BRAF; B-Raf proto-oncogene, serine/threonine kinase (7q34)

Gene Summary

Gene:BRAF; B-Raf proto-oncogene, serine/threonine kinase
Aliases: NS7, BRAF1, RAFB1, B-RAF1
Summary:This gene encodes a protein belonging to the raf/mil family of serine/threonine protein kinases. This protein plays a role in regulating the MAP kinase/ERKs signaling pathway, which affects cell division, differentiation, and secretion. Mutations in this gene are associated with cardiofaciocutaneous syndrome, a disease characterized by heart defects, mental retardation and a distinctive facial appearance. Mutations in this gene have also been associated with various cancers, including non-Hodgkin lymphoma, colorectal cancer, malignant melanoma, thyroid carcinoma, non-small cell lung carcinoma, and adenocarcinoma of lung. A pseudogene, which is located on chromosome X, has been identified for this gene. [provided by RefSeq, Jul 2008]
Databases:OMIM, VEGA, HGNC, Ensembl, GeneCard, Gene
Protein:serine/threonine-protein kinase B-raf
Updated:14 December, 2014


What does this gene/protein do?
Show (28)


What pathways are this gene/protein implicaed in?
- Dorso-ventral axis formation KEGG
- Focal adhesion KEGG
- MAPK signaling pathway KEGG
- mTOR signaling pathway KEGG
- Regulation of actin cytoskeleton KEGG
Data from KEGG and BioCarta [BIOCARTA terms] via CGAP

Cancer Overview

Research Indicators

Publications Per Year (1989-2014)
Graph generated 14 December 2014 using data from PubMed using criteria.

Literature Analysis

Mouse over the terms for more detail; many indicate links which you can click for dedicated pages about the topic.

  • Epidermal Growth Factor Receptor
  • Molecular Targeted Therapy
  • Disease-Free Survival
  • Health Care Quality Assurance
  • Adenocarcinoma
  • Immunohistochemistry
  • Ubiquitination
  • X-Ray Computed Tomography
  • Cancer Gene Expression Regulation
  • Indoles
  • Tubulin Modulators
  • Skin Cancer
  • Phosphatidylinositol 3-Kinases
  • Colorectal Cancer
  • DNA Methylation
  • Sirtuin 1
  • Recurrence
  • DNA Mutational Analysis
  • Non-Hodgkin Lymphoma
  • Treatment Failure
  • Staging
  • Melanoma
  • Thyroid Cancer
  • GTP Phosphohydrolases
  • Drug Resistance
  • p53 Protein
  • Antineoplastic Agents
  • Up-Regulation
  • BRAF
  • Proto-Oncogene Proteins
  • Lung Cancer
  • Sulfonamides
  • Protein Kinase Inhibitors
  • Chromosome 7
  • Sirolimus
  • Rectum
  • Membrane Proteins
  • Adolescents
  • Thyroid Nodule
  • Valine
  • Mutation
Tag cloud generated 14 December, 2014 using data from PubMed, MeSH and CancerIndex

Notable (5)

Scope includes mutations and abnormal protein expression.

Entity Topic PubMed Papers
MelanomaBRAF and Melanoma View Publications1309
Colorectal CancerBRAF and Colorectal Cancer View Publications1043
Thyroid CancerBRAF and Thyroid Cancer View Publications723
Lung CancerBRAF and Lung Cancer View Publications166
Non-Hodgkin LymphomaBRAF and Non-Hodgkin's Lymphoma View Publications16

Note: list is not exhaustive. Number of papers are based on searches of PubMed (click on topic title for arbitrary criteria used).

Related Links

Latest Publications: BRAF (cancer-related)

Fang M, Ou J, Hutchinson L, Green MR
The BRAF oncoprotein functions through the transcriptional repressor MAFG to mediate the CpG Island Methylator phenotype.
Mol Cell. 2014; 55(6):904-15 [PubMed] Article available free on PMC after 18/09/2015 Related Publications
Most colorectal cancers (CRCs) containing activated BRAF (BRAF[V600E]) have a CpG island methylator phenotype (CIMP) characterized by aberrant hypermethylation of many genes, including the mismatch repair gene MLH1. MLH1 silencing results in microsatellite instability and a hypermutable phenotype. Through an RNAi screen, here we identify the transcriptional repressor MAFG as the pivotal factor required for MLH1 silencing and CIMP in CRCs containing BRAF(V600E). In BRAF-positive human CRC cell lines and tumors, MAFG is bound at the promoters of MLH1 and other CIMP genes, and recruits a corepressor complex that includes its heterodimeric partner BACH1, the chromatin remodeling factor CHD8, and the DNA methyltransferase DNMT3B, resulting in hypermethylation and transcriptional silencing. BRAF(V600E) increases BRAF/MEK/ERK signaling resulting in phosphorylation and elevated levels of MAFG, which drives DNA binding. Analysis of transcriptionally silenced CIMP genes in KRAS-positive CRCs indicates that different oncoproteins direct the assembly of distinct repressor complexes on common promoters.

Related: Colorectal (Bowel) Cancer Signal Transduction MLH1

Griewank KG, Murali R, Puig-Butille JA, et al.
TERT promoter mutation status as an independent prognostic factor in cutaneous melanoma.
J Natl Cancer Inst. 2014; 106(9) [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND: Recently, TERT promoter mutations were identified at high frequencies in cutaneous melanoma tumor samples and cell lines. The mutations were found to have a UV-signature and to lead to increased TERT gene expression. We analyzed a large cohort of melanoma patients for the presence and distribution of TERT promoter mutations and their association with clinico-pathological characteristics.
METHODS: 410 melanoma tumor samples were analyzed by Sanger sequencing for the presence of TERT promoter mutations. An analysis of associations between mutation status and various clinical and pathologic variables was performed.
RESULTS: TERT promoter mutations were identified in 154 (43%) of 362 successfully sequenced melanomas. Mutation frequencies varied between melanoma subtype, being most frequent in melanomas arising in nonacral skin (48%) and melanomas with occult primary (50%), and less frequent in mucosal (23%), and acral (19%) melanomas. Mutations carried a UV signature (C>T or CC>TT). The presence of TERT promoter mutations was associated with factors such as BRAF or NRAS mutation (P < .001), histologic type (P = .002), and Breslow thickness (P < .001). TERT promoter mutation was independently associated with poorer overall survival in patients with nonacral cutaneous melanomas (median survival 80 months vs 291 months for wild-type; hazard ratio corrected for other covariates 2.47; 95% confidence interval [CI] = 1.29 to 4.74; P = .006).
CONCLUSIONS: UV-induced TERT promoter mutations are one of the most frequent genetic alterations in melanoma, with frequencies varying depending on melanoma subtype. In nonacral cutaneous melanomas, presence of TERT promoter mutations is independently associated with poor prognosis.

Related: Melanoma Cancer of Unknown Primary TERT

Koopmans AE, Ober K, Dubbink HJ, et al.
Prevalence and implications of TERT promoter mutation in uveal and conjunctival melanoma and in benign and premalignant conjunctival melanocytic lesions.
Invest Ophthalmol Vis Sci. 2014; 55(9):6024-30 [PubMed] Related Publications
PURPOSE: Hot-spot mutations in the promoter region of telomerase reverse transcriptase (TERT promoter mutations) occur frequently in cutaneous and conjunctival melanoma and are exceedingly rare in uveal melanoma. No information is available on the presence of these mutations in the conjunctival melanocytic precursor lesion primary acquired melanosis (PAM). We tested a cohort of uveal and conjunctival melanomas as well as conjunctival benign and premalignant melanocytic lesions for TERT promoter mutations in order to elucidate the role of these mutations in tumor progression.
METHODS: TERT promoter mutation analysis on fresh tumor DNA and DNA from formalin-fixed, paraffin-embedded specimens was performed by SNaPshot analysis in 102 uveal melanomas, 39 conjunctival melanomas, 26 PAM with atypia, 14 PAM without atypia, and 56 conjunctival nevi.
RESULTS: Mutations of the TERT promoter were not identified in conjunctival nevi or PAM without atypia, but were detected in 2/25 (8%) of PAM with atypia and 16/39 (41%) of conjunctival melanomas. A single TERT promoter mutation was detected in 102 uveal melanomas (1%).
CONCLUSIONS: We present the second documented case of TERT promoter mutation in uveal melanoma. In comparison with other types of melanoma, TERT promoter mutations occur at extremely low frequency in uveal melanoma. TERT promoter mutations are frequent in conjunctival melanoma and occur at lower frequency in PAM with atypia but were not detected in benign conjunctival melanocytic lesions. These findings favor a pathogenetic tumor progression role for TERT promoter mutations in conjunctival melanocytic lesions.

Related: Melanoma Ocular Melanoma IntraOcular Melanoma Cancer Prevention and Risk Reduction TERT

Wiland HO, Shadrach B, Allende D, et al.
Morphologic and molecular characterization of traditional serrated adenomas of the distal colon and rectum.
Am J Surg Pathol. 2014; 38(9):1290-7 [PubMed] Related Publications
Of the serrated polyps, the origin, morphologic features, molecular alterations, and natural history of traditional serrated adenomas (TSAs) are the least understood. Recent studies suggest that these polyps may arise from precursor lesions. The frequencies of KRAS and BRAF mutations vary between these studies, and only 1 small study has measured CpG island methylation using current markers of methylation. Mutations in GNAS, a gene commonly mutated in colorectal villous adenomas, have not been fully evaluated in TSAs. Finally, the expression of annexin A10 (ANXA10), a recently discovered marker of sessile serrated adenomas/polyps, has not been studied in these polyps. To further characterize these polyps, 5 gastrointestinal pathologists reviewed 55 left-sided polyps diagnosed as TSA at a single institution. Pathologists assessed various histologic features including cytoplasmic eosinophilia, ectopic crypt foci, presence of conventional dysplasia, and presence of precursor serrated lesions. KRAS, BRAF, and GNAS mutational analysis was performed, as well as CpG island methylation and ANXA10 immunohistochemistry. Ectopic crypt foci were seen in 62% of TSAs. Precursor lesions were seen in 24% of the study polyps, most of which were hyperplastic polyps. KRAS and BRAF mutations were common and were present in 42% and 48% of polyps, respectively. GNAS mutations occurred in 8% of polyps, often in conjunction with a BRAF mutation. Unlike sessile serrated adenomas/polyps, TSAs rarely had diffuse expression of ANXA10. Importantly, BRAF-mutated TSAs had more widespread methylation of a 5-marker CpG island panel compared with KRAS-mutated polyps. However, ectopic crypt foci, a proposed defining feature of TSA, were not associated with any specific molecular alteration.

Related: KRAS gene

McDaniel AS, Zhai Y, Cho KR, et al.
HRAS mutations are frequent in inverted urothelial neoplasms.
Hum Pathol. 2014; 45(9):1957-65 [PubMed] Article available free on PMC after 01/03/2015 Related Publications
Inverted urothelial papilloma (IUP) is an uncommon neoplasm of the urinary bladder with distinct morphologic features. Studies regarding the role of human papillomavirus (HPV) in the etiology of IUP have provided conflicting evidence of HPV infection. In addition, little is known regarding the molecular alterations present in IUP or other urothelial neoplasms, which might demonstrate inverted growth pattern like low-grade or high-grade urothelial carcinoma (UCA). Here, we evaluated for the presence of common driving somatic mutations and HPV within a cohort of IUPs, (n = 7) noninvasive low-grade papillary UCAs with inverted growth pattern (n = 5), and noninvasive high-grade papillary UCAs with inverted growth pattern (n = 8). HPV was not detected in any case of IUP or inverted UCA by either in situ hybridization or by polymerase chain reaction. Next-generation sequencing identified recurrent mutations in HRAS (Q61R) in 3 of 5 IUPs, described for the first time in this neoplasm. Additional mutations of Ras pathway members were detected including HRAS, KRAS, and BRAF. The presence of Ras pathway member mutations at a relatively high rate suggests this pathway may contribute to pathogenesis of inverted urothelial neoplasms. In addition, we did not find any evidence supporting a role for HPV in the etiology of IUP.

Related: Transitional Cell Cancer of the Renal Pelvis and Ureter Bladder Cancer Bladder Cancer - Molecular Biology

Ryslik GA, Cheng Y, Cheung KH, et al.
A spatial simulation approach to account for protein structure when identifying non-random somatic mutations.
BMC Bioinformatics. 2014; 15:231 [PubMed] Article available free on PMC after 01/03/2015 Related Publications
BACKGROUND: Current research suggests that a small set of "driver" mutations are responsible for tumorigenesis while a larger body of "passenger" mutations occur in the tumor but do not progress the disease. Due to recent pharmacological successes in treating cancers caused by driver mutations, a variety of methodologies that attempt to identify such mutations have been developed. Based on the hypothesis that driver mutations tend to cluster in key regions of the protein, the development of cluster identification algorithms has become critical.
RESULTS: We have developed a novel methodology, SpacePAC (Spatial Protein Amino acid Clustering), that identifies mutational clustering by considering the protein tertiary structure directly in 3D space. By combining the mutational data in the Catalogue of Somatic Mutations in Cancer (COSMIC) and the spatial information in the Protein Data Bank (PDB), SpacePAC is able to identify novel mutation clusters in many proteins such as FGFR3 and CHRM2. In addition, SpacePAC is better able to localize the most significant mutational hotspots as demonstrated in the cases of BRAF and ALK. The R package is available on Bioconductor at: http://www.bioconductor.org/packages/release/bioc/html/SpacePAC.html.
CONCLUSION: SpacePAC adds a valuable tool to the identification of mutational clusters while considering protein tertiary structure.

Related: Cancer Prevention and Risk Reduction

Soeda H, Shimodaira H, Gamoh M, et al.
Phase II trial of cetuximab plus irinotecan for oxaliplatin- and irinotecan-based chemotherapy-refractory patients with advanced and/or metastatic colorectal cancer: evaluation of efficacy and safety based on KRAS mutation status (T-CORE0801).
Oncology. 2014; 87(1):7-20 [PubMed] Related Publications
BACKGROUND: Mutations in the KRAS gene have been identified as negative predictors of response to anti-epidermal growth factor receptor (EGFR) monoclonal antibody therapy by patients with metastatic colorectal cancer (mCRC). However, it has been based on the study of mainly Caucasian mCRC patients. This prospective study investigated the relationship between the mutation status of EGFR-related genes including KRAS and the response rate (RR) to cetuximab plus irinotecan therapy in Japanese mCRC patients.
METHODS: Samples taken from 43 chemotherapy-refractory mCRC patients who had undergone cetuximab plus irinotecan therapy at 11 medical centers in Japan were subjected to direct DNA sequencing to determine the KRAS, BRAF, PIK3CA, NRAS, and AKT1 mutation status. The clinical outcome after the treatment was evaluated for each mutation status.
RESULTS: KRAS mutations were detected in 31.7% of 41 eligible patients. The RR to cetuximab plus irinotecan therapy was found to be 17.9 and 0% in the KRAS wild-type and mutant subgroups, respectively.
CONCLUSION: Despite the identification of a lower-than-expected RR to treatment by the KRAS wild-type subgroup, KRAS mutation status appears to be a useful predictive marker of response to cetuximab plus irinotecan therapy in Japanese mCRC patients.

Related: Colorectal (Bowel) Cancer KRAS gene Oxaliplatin Irinotecan NRAS Cetuximab (Erbitux)

Lin CC, Lin JK, Lin TC, et al.
The prognostic role of microsatellite instability, codon-specific KRAS, and BRAF mutations in colon cancer.
J Surg Oncol. 2014; 110(4):451-7 [PubMed] Related Publications
BACKGROUND: This study aimed to establish a correlation between MSI, KRAS mutations, and BRAF(V600E) in colon cancer and to investigate the prognostic effect.
METHODS: Colon cancer patients who underwent surgical intervention were enrolled. MSI status was identified by genotyping, and the mutational statuses of KRAS and BRAF were determined by MassARRAY, targeting 22 mutations. The clinicopathological differences and correlations between these factors were analyzed.
RESULTS: Among 1,063 patients, tumors with MSI-H were significantly associated with BRAF(V600E) (P = 0.001). KRAS and BRAF mutations were mutually exclusive (P = 0.001). Patients with MSI-H tumors had significantly improved overall survival compared with patients that had microsatellite instability-low/stable (MSI-L/MSS) tumors (hazard ratio 0.686: 95% confidence interval: 0.479-1.162, P = 0.040). In addition, the BRAF(V600E) mutation was a poor prognostic factor in tumors with MSI-L/MSS (P = 0.020). KRAS mutations were not prognostic factors, but sub-group analysis demonstrated that mutations in KRAS codon 12 were associated with significantly worse survival than wild-type KRAS, mutations in KRAS codon 13, or mutations elsewhere.
CONCLUSIONS: MSI and the BRAF(V600E) mutation have a prognostic impact in colon cancer. Variable KRAS mutations may have different effects on colon cancers; further studies are needed to verify these results.

Related: KRAS gene

Holderfield M, Deuker MM, McCormick F, McMahon M
Targeting RAF kinases for cancer therapy: BRAF-mutated melanoma and beyond.
Nat Rev Cancer. 2014; 14(7):455-67 [PubMed] Article available free on PMC after 01/07/2015 Related Publications
The identification of mutationally activated BRAF in many cancers altered our conception of the part played by the RAF family of protein kinases in oncogenesis. In this Review, we describe the development of BRAF inhibitors and the results that have emerged from their analysis in both the laboratory and the clinic. We discuss the spectrum of RAF mutations in human cancer and the complex interplay between the tissue of origin and the response to RAF inhibition. Finally, we enumerate mechanisms of resistance to BRAF inhibition that have been characterized and postulate how strategies of RAF pathway inhibition may be extended in scope to benefit not only the thousands of patients who are diagnosed annually with BRAF-mutated metastatic melanoma but also the larger patient population with malignancies harbouring mutationally activated RAF genes that are ineffectively treated with the current generation of BRAF kinase inhibitors.

Related: Melanoma Skin Cancer

Taieb J, Tabernero J, Mini E, et al.
Oxaliplatin, fluorouracil, and leucovorin with or without cetuximab in patients with resected stage III colon cancer (PETACC-8): an open-label, randomised phase 3 trial.
Lancet Oncol. 2014; 15(8):862-73 [PubMed] Related Publications
BACKGROUND: Since the 1990s, fluorouracil-based adjuvant chemotherapy has significantly reduced the risk of tumour recurrence in patients with stage III colon cancer. We aimed to assess whether the addition of cetuximab to standard adjuvant oxaliplatin, fluorouracil, and leucovorin chemotherapy (FOLFOX4) in patients with stage III colon cancer improved disease-free survival (DFS).
METHODS: For this open-label, randomised phase 3 study done in nine European countries, we enrolled patients through an interactive voice response system to the central randomisation centre, with a central stratified permuted block randomisation procedure. We randomly assigned patients with resected (R0) stage III disease (1:1) to receive 12 cycles of FOLFOX4 twice a week with or without cetuximab. Patients were stratified by N-status (N1 vs N2), T-status (T1-3 vs T4), and obstruction or perforation status (no obstruction and no perforation vs obstruction or perforation or both). A protocol amendment (applied in June, 2008, after 2096 patients had been randomly assigned to treatment-restricted enrolment to patients with tumours wild-type at codons 12 and 13 in exon 2 of the KRAS gene (KRAS exon 2 wild-type). The primary endpoint was DFS. Analysis was intention to treat in all patients with KRAS exon 2 wild-type tumours. The study is registered at EudraCT, number 2005-003463-23.
FINDINGS: Between Dec 22, 2005, and Nov 5, 2009, 2559 patients from 340 sites in Europe were randomly assigned. Of these patients, 1602 had KRAS exon 2 wild-type tumours (intention-to-treat population), 791 in the FOLFOX4 plus cetuximab group and 811 in the FOLFOX4 group. Median follow-up was 3·3 years (IQR 3·2-3·4). In the experimental and control groups, DFS was similar in the intention-to-treat population (hazard ratio [HR] 1·05; 95% CI 0·85-1·29; p=0·66), and in patients with KRAS exon 2/BRAF wild-type (n=984, HR 0·99; 95% CI 0·76-1·28) or KRAS exon 2-mutated tumours (n=742, HR 1·06; 95% CI 0·82-1·37). We noted heterogeneous responses to the addition of cetuximab in preplanned subgroup analyses. Grade 3 or 4 acne-like rash (in 209 of 785 patients [27%] vs four of 805 [<1%]), diarrhoea (113 [14%] vs 70 [9%]), mucositis (63 [8%] vs 10 [1%]), and infusion-related reactions (55 [7%] vs 30 [4%]) were more frequent in patients treated with FOLFOX4 plus cetuximab than in those patients who received FOLFOX4 alone.
INTERPRETATION: The addition of cetuximab to FOLFOX4 did not improve DFS compared with FOLFOX4 alone in patients with KRAS exon 2 wild-type resected stage III colon cancer. This trial cannot conclude on the benefit of cetuximab in the studied population, but the heterogeneity of response suggests that further investigation of the role of FOLFOX4 plus cetuximab in specific patient subgroups is warranted.
FUNDING: Fédération Francophone de Cancérologie Digestive (FFCD), Merck KGaA, and Sanofi-Aventis.

Related: Fluorouracil Leucovorin KRAS gene Cetuximab (Erbitux)

Chou A, Toon CW, Clarkson A, et al.
Loss of ARID1A expression in colorectal carcinoma is strongly associated with mismatch repair deficiency.
Hum Pathol. 2014; 45(8):1697-703 [PubMed] Related Publications
ARID1A is a tumor suppressor gene involved in chromatin remodelling. ARID1A mutations and loss of protein expression occur commonly in endometrioid and gynecological clear cell carcinoma where they are associated with mismatch repair (MMR) deficiency. We assessed ARID1A expression in a large cohort of colorectal carcinomas (CRCs). Immunohistochemistry for ARID1A was performed on whole sections from 100 CRCs and on 1876 CRCs in tissue microarray format. There was complete concordance between the staining on whole slides and tissue microarray sections. Loss of staining was found in 110 (5.9%) of 1876 CRCs and was strongly associated with older age, right sided location, large size, BRAF V600E mutation, MMR deficiency, high histological grade and medullary morphology, (all P < .01). There was a trend towards loss of expression being more common in females (P = .06). When subclassified by combined BRAF V600E mutation and MMR status, loss of ARID1A expression was found most commonly in CRCs with the BRAF V600E mutated, MMR- deficient phenotype (58 of 232 cases, 25%, P < .01). In univariate and multivariate analysis, loss of ARID1A expression was not associated with overall survival-hazard ratio 1.05 (0.68-1.64) and 0.60 (0.24-1.44), respectively. All carcinomas arising in patients with known Lynch syndrome (n = 12) were ARID1A positive. We conclude that loss of ARID1A expression occurs in a small but significant proportion of CRCs where it is strongly correlated with mismatch repair deficiency and other clinical and pathological features associated with somatic hypermethylation.

Related: Colorectal (Bowel) Cancer ARID1A gene

Viros A, Sanchez-Laorden B, Pedersen M, et al.
Ultraviolet radiation accelerates BRAF-driven melanomagenesis by targeting TP53.
Nature. 2014; 511(7510):478-82 [PubMed] Article available free on PMC after 24/01/2015 Related Publications
Cutaneous melanoma is epidemiologically linked to ultraviolet radiation (UVR), but the molecular mechanisms by which UVR drives melanomagenesis remain unclear. The most common somatic mutation in melanoma is a V600E substitution in BRAF, which is an early event. To investigate how UVR accelerates oncogenic BRAF-driven melanomagenesis, we used a BRAF(V600E) mouse model. In mice expressing BRAF(V600E) in their melanocytes, a single dose of UVR that mimicked mild sunburn in humans induced clonal expansion of the melanocytes, and repeated doses of UVR increased melanoma burden. Here we show that sunscreen (UVA superior, UVB sun protection factor (SPF) 50) delayed the onset of UVR-driven melanoma, but only provided partial protection. The UVR-exposed tumours showed increased numbers of single nucleotide variants and we observed mutations (H39Y, S124F, R245C, R270C, C272G) in the Trp53 tumour suppressor in approximately 40% of cases. TP53 is an accepted UVR target in human non-melanoma skin cancer, but is not thought to have a major role in melanoma. However, we show that, in mice, mutant Trp53 accelerated BRAF(V600E)-driven melanomagenesis, and that TP53 mutations are linked to evidence of UVR-induced DNA damage in human melanoma. Thus, we provide mechanistic insight into epidemiological data linking UVR to acquired naevi in humans. Furthermore, we identify TP53/Trp53 as a UVR-target gene that cooperates with BRAF(V600E) to induce melanoma, providing molecular insight into how UVR accelerates melanomagenesis. Our study validates public health campaigns that promote sunscreen protection for individuals at risk of melanoma.

Related: Melanoma Skin Cancer TP53

Steinestel K, Lennerz JK, Eder S, et al.
Invasion pattern and histologic features of tumor aggressiveness correlate with MMR protein expression, but are independent of activating KRAS and BRAF mutations in CRC.
Virchows Arch. 2014; 465(2):155-63 [PubMed] Related Publications
KRAS/BRAF mutation testing and mismatch repair (MMR) protein immunohistochemistry have an established role in routine diagnostic evaluation of colorectal carcinoma (CRC). However, since the exact impact of these molecular characteristics on tumor morphology and behavior is still subject to research, the aim of our study was to examine associations between molecular and morphologic features that had not been analyzed in this combination before. KRAS (codons 12, 13, and 61) and BRAF (codon 600) mutation status and MMR protein expression were analyzed in a consecutive series of 117 CRC samples using DNA pyrosequencing and immunohistochemistry. Tumor cell budding, infiltration pattern, and peritumoral lymphocytic (PTL) reaction was assessed applying established criteria. Molecular and morphological findings were correlated applying chi-square and Fisher's exact test. We found KRAS or BRAF mutations in 40 and 8 % of samples, while loss of MMR protein expression was observed in 11 %. Tumor budding was significantly associated with infiltrative growth, absence of PTLs, and blood and lymph vessel infiltration. Neither KRAS nor BRAF mutations were associated with a certain growth pattern or budding intensity of CRC, but loss of MMR protein expression was found in context with BRAF mutation, expanding growth, and presence of PTLs. Our results confirm an association between loss of MMR protein expression, presence of activating BRAF mutation, expanding growth, and PTL reaction as well as between tumor budding, infiltrative growth pattern, and tumor aggressiveness; however, there was no such association between the presence of an activating KRAS or BRAF mutation and a distinct invasion pattern or tumor aggressiveness in CRC.

Related: Colorectal (Bowel) Cancer KRAS gene

Zannoni GF, Improta G, Chiarello G, et al.
Mutational status of KRAS, NRAS, and BRAF in primary clear cell ovarian carcinoma.
Virchows Arch. 2014; 465(2):193-8 [PubMed] Related Publications
Ovarian clear cell carcinoma (OCCC) is a subtype of epithelial ovarian cancer with characteristic biological features and aggressive clinical behavior. OCCCs show a pattern of gene mutations different from other type I ovarian malignancies, notably a higher frequency of PIK3CA mutations. In low grade serous ovarian cancer, KRAS and BRAF mutations are frequent, but little data are available on the mutational status of these genes in OCCCs. To clarify this issue, we designed a clinicopathological study with the aim to establish the incidence of KRAS, NRAS, and BRAF hot spot mutations in OCCC. Between December 2006 and June 2012, 22 patients with a proven diagnosis of OCCC were admitted to our Institutions. In all cases, final diagnosis was established according to FIGO and WHO criteria. All women received complete surgical staging. The PyroMark Q24 system (Qiagen GmbH, Hilden, Germany) was used for pyrosequencing analysis of KRAS, NRAS, and BRAF hot spot regions on 2.5-μm sections of formalin-fixed paraffin-embedded tissue from primary OCCC. Pyrosequencing analysis of KRAS, NRAS, and BRAF hot spot regions revealed the presence of mutations only at codon 12 in exon 2 of KRAS in 3 of 22 (14 %) cases. We found no mutations in the hot spot regions of NRAF (exons 2, 3, 4) or BRAF (exon 15). The median age of women with a KRAS mutated OCCC was 74 years. These OCCC were unilateral FIGO stage IA lesions in two cases associated with foci of endometriosis. We conclude that in 14 % of OCCCs, a KRAS mutation occurs in codon 2 exon 2. NRAS and BRAF mutations were not found.

Related: Ovarian Cancer KRAS gene NRAS

Poller DN, Glaysher S, Agrawal A, et al.
BRAF V600 co-testing in thyroid FNA cytology: short-term experience in a large cancer centre in the UK.
J Clin Pathol. 2014; 67(8):684-9 [PubMed] Related Publications
AIMS: To ascertain whether BRAF V600 mutational analysis is useful for diagnosis of thyroid cancer in thyroid fine needle aspirate (FNA).
METHODS: Over 8 months thyroid FNAs reported as Thy 3F (neoplasm possible/suggestive of follicular neoplasm), Thy4 (suspicious of malignancy) and Thy 5 (malignant) were tested for BRAF V600 mutation and managed as malignant if mutations were present.
RESULTS: Of 207 FNAs from 176 patients, 5 were Thy 5, 19 Thy 4, 36 Thy 3f, 13 Thy 3a, 84 Thy 2 and 50 Thy 1. 11 Thy 3f, 15 Thy 4 and 3 Thy 5 FNAs were tested for BRAF V600 mutation. 0 Thy 3F cases, 6 Thy 4 and 1 Thy 5 (24% of the total tested) showed evidence of mutation. Four patients with BRAF V600 mutation underwent surgery to remove all thyroid tissue, two patients received a lobectomy and one patient is awaiting thyroidectomy. All patients with BRAF V600 mutation were found to have malignancy on final histology, with a diagnostic sensitivity for malignancy excluding coincidental microcarcinoma of 43% and specificity of 100%.
CONCLUSIONS: BRAF V600 mutational analysis can enable single-stage total thyroidectomy for carcinoma if gene mutation is present in preoperative FNA. BRAF V600 co-testing may reduce the need for completion thyroidectomy with implied cost savings and lower patient morbidity associated with completion thyroidectomy when the cytology is inconclusive but where BRAF V600 mutation is identified in preoperative thyroid FNA.

Related: Thyroid Cancer

Shiovitz S, Bertagnolli MM, Renfro LA, et al.
CpG island methylator phenotype is associated with response to adjuvant irinotecan-based therapy for stage III colon cancer.
Gastroenterology. 2014; 147(3):637-45 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
BACKGROUND & AIMS: The CpG island methylator phenotype (CIMP), defined by a high frequency of aberrantly methylated genes, is a characteristic of a subclass of colon tumors with distinct clinical and molecular features. Cohort studies have produced conflicting results on responses of CIMP-positive tumors to chemotherapy. We assessed the association between tumor CIMP status and survival of patients receiving adjuvant fluorouracil and leucovorin alone or with irinotecan (IFL).
METHODS: We analyzed data from patients with stage III colon adenocarcinoma randomly assigned to groups given fluorouracil and leucovorin or IFL after surgery, from April 1999 through April 2001. The primary end point of the trial was overall survival and the secondary end point was disease-free survival. DNA isolated from available tumor samples (n = 615) was used to determine CIMP status based on methylation patterns at the CACNA1G, IGF2, NEUROG1, RUNX3, and SOCS1 loci. The effects of CIMP on survival were modeled using Kaplan-Meier and Cox proportional hazards; interactions with treatment and BRAF, KRAS, and mismatch repair (MMR) status were also investigated.
RESULTS: Of the tumor samples characterized for CIMP status, 145 were CIMP positive (23%). Patients with CIMP-positive tumors had shorter overall survival times than patients with CIMP-negative tumors (hazard ratio = 1.36; 95% confidence interval: 1.01-1.84). Treatment with IFL showed a trend toward increased overall survival for patients with CIMP-positive tumors, compared with treatment with fluorouracil and leucovorin (hazard ratio = 0.62; 95% CI: 0.37-1.05; P = .07), but not for patients with CIMP-negative tumors (hazard ratio = 1.38; 95% CI: 1.00-1.89; P = .049). In a 3-way interaction analysis, patients with CIMP-positive, MMR-intact tumors benefited most from the addition of irinotecan to fluorouracil and leucovorin therapy (for the interaction, P = .01). CIMP was more strongly associated with response to IFL than MMR status. Results for disease-free survival times were comparable among all analyses.
CONCLUSIONS: Patients with stage III, CIMP-positive, MMR-intact colon tumors have longer survival times when irinotecan is added to combination therapy with fluorouracil and leucovorin.

Related: Fluorouracil Leucovorin Irinotecan

Kris MG, Johnson BE, Berry LD, et al.
Using multiplexed assays of oncogenic drivers in lung cancers to select targeted drugs.
JAMA. 2014; 311(19):1998-2006 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
IMPORTANCE: Targeting oncogenic drivers (genomic alterations critical to cancer development and maintenance) has transformed the care of patients with lung adenocarcinomas. The Lung Cancer Mutation Consortium was formed to perform multiplexed assays testing adenocarcinomas of the lung for drivers in 10 genes to enable clinicians to select targeted treatments and enroll patients into clinical trials.
OBJECTIVES: To determine the frequency of oncogenic drivers in patients with lung adenocarcinomas and to use the data to select treatments targeting the identified driver(s) and measure survival.
DESIGN, SETTING, AND PARTICIPANTS: From 2009 through 2012, 14 sites in the United States enrolled patients with metastatic lung adenocarcinomas and a performance status of 0 through 2 and tested their tumors for 10 drivers. Information was collected on patients, therapies, and survival.
INTERVENTIONS: Tumors were tested for 10 oncogenic drivers, and results were used to select matched targeted therapies.
MAIN OUTCOMES AND MEASURES: Determination of the frequency of oncogenic drivers, the proportion of patients treated with genotype-directed therapy, and survival.
RESULTS: From 2009 through 2012, tumors from 1007 patients were tested for at least 1 gene and 733 for 10 genes (patients with full genotyping). An oncogenic driver was found in 466 of 733 patients (64%). Among these 733 tumors, 182 tumors (25%) had the KRAS driver; sensitizing EGFR, 122 (17%); ALK rearrangements, 57 (8%); other EGFR, 29 (4%); 2 or more genes, 24 (3%); ERBB2 (formerly HER2), 19 (3%); BRAF, 16 (2%); PIK3CA, 6 (<1%); MET amplification, 5 (<1%); NRAS, 5 (<1%); MEK1, 1 (<1%); AKT1, 0. Results were used to select a targeted therapy or trial in 275 of 1007 patients (28%). The median survival was 3.5 years (interquartile range [IQR], 1.96-7.70) for the 260 patients with an oncogenic driver and genotype-directed therapy compared with 2.4 years (IQR, 0.88-6.20) for the 318 patients with any oncogenic driver(s) who did not receive genotype-directed therapy (propensity score-adjusted hazard ratio, 0.69 [95% CI, 0.53-0.9], P = .006).
CONCLUSIONS AND RELEVANCE: Actionable drivers were detected in 64% of lung adenocarcinomas. Multiplexed testing aided physicians in selecting therapies. Although individuals with drivers receiving a matched targeted agent lived longer, randomized trials are required to determine if targeting therapy based on oncogenic drivers improves survival.
TRIAL REGISTRATION: clinicaltrials.gov Identifier: NCT01014286.

Related: Lung Cancer

Tseng D, Kim J, Warrick A, et al.
Oncogenic mutations in melanomas and benign melanocytic nevi of the female genital tract.
J Am Acad Dermatol. 2014; 71(2):229-36 [PubMed] Related Publications
BACKGROUND: The genetic heterogeneity of melanomas and melanocytic nevi of the female genital tract is poorly understood.
OBJECTIVE: We aim to characterize the frequency of mutations of the following genes: BRAF, NRAS, KIT, GNA11, and GNAQ in female genital tract melanomas. We also characterize the frequency of BRAF mutations in female genital tract melanomas compared with melanocytic nevi.
METHODS: Mutational screening was performed on the following female genital tract melanocytic neoplasms: 25 melanomas, 7 benign melanocytic nevi, and 4 atypical melanocytic nevi.
RESULTS: Of the 25 female genital tract melanoma specimens queried, KIT mutations were detected in 4 (16.0%), NRAS mutations in 4 (16.0%), and BRAF mutations in 2 (8.0%) samples. Two of the tumors with KIT mutations harbored double mutations in the same exon. No GNAQ or GNA11 mutations were identified among 11 melanomas screened. BRAF V600E mutations were detected in 7 of 7 benign melanocytic genital nevi (100%) and 3 of 4 atypical genital nevi (75%).
LIMITATIONS: Our study is limited by the small sample size of this rare subset of melanomas.
CONCLUSION: KIT, NRAS, and BRAF mutations are found in a subset of female genital tract melanomas. Screening for oncogenic mutations is important for developing and applying clinical therapies for melanomas of the female genital tract.

Related: Gynacological Cancers Melanoma NRAS

Bellido F, Pineda M, Sanz-Pamplona R, et al.
Comprehensive molecular characterisation of hereditary non-polyposis colorectal tumours with mismatch repair proficiency.
Eur J Cancer. 2014; 50(11):1964-72 [PubMed] Related Publications
BACKGROUND: Hereditary non-polyposis colorectal cancer (CRC) without mismatch repair (MMR) defects occurs in almost half of high-risk CRC families, but its genetic cause(s) is(are) still unknown. We aimed to identify unique molecular features that differentiate hereditary from sporadic MMR-proficient colorectal tumours.
METHODS: Genomic alterations in 16 tumours from 14 Amsterdam I-II families were studied using the genome-wide copy number OncoScan™ FFPE microarray. Somatic mutation hotspots in BRAF, KRAS, PIK3CA and TP53 were analysed in 37 colorectal tumours from 26 families and in 99 sporadic MMR-proficient CRCs, using direct automated sequencing and KASPar genotyping assays. CpG methylation index was studied in 25 tumours from 19 families by methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA).
RESULTS: Our findings indicate that hereditary MMR-proficient tumours have overlapping genomic profiles to those obtained in sporadic cases, both suggestive of high chromosomal instability, and no high CpG methylation index. Nevertheless, we identified a significant increase in the frequency of chromosome 2p and 2q gains, and of 10 q loss in Amsterdam I families, as well as low frequency of >2 Mb copy-neutral or -gained loss of heterozygosity (LOH). No statistically significant differences in the frequency of BRAF, KRAS, PIK3CA and TP53 mutations or in the gene mutation patterns were observed. However, TP53 mutations appeared almost twice more frequently in sporadic tumours.
CONCLUSIONS: Overall, hereditary MMR-proficient CRCs display similar molecular characteristics than their sporadic counterparts. However, the differences identified, such as the chromosome 2 gain, 10 q loss, or the under-representation of TP53 mutations, if validated in larger series, might be of relevance in the clinical setting and/or in the identification of germline defects underlying some of these familial cases.

Takahashi N, Yamada Y, Taniguchi H, et al.
Combined assessment of endothelial growth factor receptor dual color in situ hybridization and immunohistochemistry with downstream gene mutations in prediction of response to the anti-EGFR therapy for patients with metastatic colorectal cancer.
Arch Med Res. 2014; 45(5):366-74 [PubMed] Related Publications
BACKGROUND AND AIMS: Biomarkers associated with anti-EGFR antibodies therapy have been investigated in metastatic colorectal cancer (CRC). We conducted this study to evaluate the clinical utility of a combined assessment of EGFR status and genomic mutations of the EGFR downstream signal pathway in predicting the efficacy of anti-EGFR antibody treatment.
METHODS: We collected formalin-fixed paraffin-embedded tumor tissues and evaluated the EGFR status by immunohistochemistry (IHC), dual color in situ hybridization (DISH) and genomic analyses of KRAS, BRAF, PIK3CA and NRAS by direct sequencing.
RESULTS: A total of 129 patients were evaluated in our study. Among KRAS wild-type patients, EGFR DISH positivity was associated with a higher response rate than DISH negativity (56.3 vs. 21.1%, p = 0.011). A subgroup with EGFR DISH positivity plus IHC3+ and wild-type of EGFR downstream gene mutations achieved higher response rate and disease control rate. EGFR DISH positivity, KRAS codon 146 mutation and NRAS codon 61 mutation were prognostic factors in both progression-free survival and overall survival by multivariate analyses.
CONCLUSIONS: Combined assessment of DISH plus IHC and EGFR downstream gene mutations was useful to predict the response to anti-EGFR antibodies treatment in metastatic colorectal cancer patients in our study.

Related: Monoclonal Antibodies Colorectal (Bowel) Cancer KRAS gene Panitumumab (Vectibix) Irinotecan NRAS Cetuximab (Erbitux)

Giordano TJ, Beaudenon-Huibregtse S, Shinde R, et al.
Molecular testing for oncogenic gene mutations in thyroid lesions: a case-control validation study in 413 postsurgical specimens.
Hum Pathol. 2014; 45(7):1339-47 [PubMed] Related Publications
Molecular testing for oncogenic gene alterations provides clinically actionable information essential for the optimal management of follicular cell thyroid cancer. We aimed to establish the distribution and frequency of common oncogenic gene mutations and chromosomal rearrangements in a comprehensive set of benign and malignant thyroid lesions. A case-control study was conducted in 413 surgical cases comprising 17 distinct histopathologic categories, 244 malignant, 169 benign, and 304 double-blinded specimens. Seventeen alterations of BRAF, HRAS, KRAS, NRAS, PAX8, and RET genes were evaluated using a single validated technology platform. Following verification of analytical sensitivity, accuracy, and precision in model and surgical specimens, 152 molecular positive results were generated in lesions representing multiple stages of progression and epithelial differentiation as well as rare subtypes of primary, secondary, or recurring tumors. Single mutations were found in 58% of primary malignant lesions and 12% of benign (P < .001). In the blinded validation set, mutation distribution and frequency were distinct across variants of follicular and papillary carcinomas. BRAF or RET-PTC was detected exclusively in malignant lesions but not in follicular carcinomas (P < .001). RAS or PAX8-PPARG were present in 23% of adenomas, and NRAS was found in a single nonneoplastic lesion (P = .0014). These data substantiate the diagnostic utility of molecular testing for oncogenic mutations and validate its performance in a variety of surgical specimens. Standardized and validated multianalyte molecular panels can complement the preoperative and postoperative assessment of thyroid nodules and support a growing number of clinical and translational applications with potential diagnostic, prognostic, or theranostic utility.

Related: Thyroid Cancer

van Engen-van Grunsven AC, Küsters-Vandevelde HV, De Hullu J, et al.
NRAS mutations are more prevalent than KIT mutations in melanoma of the female urogenital tract--a study of 24 cases from the Netherlands.
Gynecol Oncol. 2014; 134(1):10-4 [PubMed] Related Publications
OBJECTIVE: The aim of this study was to evaluate a series of primary melanomas of the female urogenital tract for oncogenic mutations in KIT, NRAS and BRAF in order to identify patients who may be amenable to targeted therapy.
METHODS: We reviewed twenty-four cases of female urogenital tract melanomas and used Sanger sequencing analysis for the detection of oncogenic mutations in exons 9, 11, 13, and 17 of KIT; exons 2 and 3 of NRAS; and exon 15 of BRAF.
RESULTS: Twenty-four patients were included: fourteen vaginal melanomas, four cervical melanomas, five urethral melanomas and one vulvar melanoma. NRAS mutations (4/24, 21%) were more prevalent than KIT mutations (1/24, 4%), while BRAF mutations were absent. Three of four NRAS mutations were present in vaginal melanomas (21%), mainly affecting codon 61 (3/4). They were mutually exclusive with the KIT mutation. The KIT mutation was present in a vaginal melanoma and affected exon 17.
CONCLUSIONS: Melanomas of the female urogenital tract relatively commonly harbor mutations in NRAS; this makes NRAS an interesting therapeutic target for these patients in the advanced setting. KIT mutations were rare in our study in contrast to some previous reports. We cannot exclude that anatomical site-related differences and/or population related differences in KIT mutation frequency exist within urogenital tract melanomas.

Related: Gynacological Cancers Melanoma NRAS

Laforest A, Aparicio T, Zaanan A, et al.
ERBB2 gene as a potential therapeutic target in small bowel adenocarcinoma.
Eur J Cancer. 2014; 50(10):1740-6 [PubMed] Related Publications
AIM OF THE STUDY: Small bowel adenocarcinoma (SBA) is a rare and aggressive tumour with poor outcomes. Because of its low incidence, the number prospective studies remains insufficient leading to poor knowledge and absence of standard of care. Aiming to better understand small bowel carcinogenesis we investigated the frequency of somatic mutations in a large data set of patients in more than 740 mutational hotspots among 46 genes.
METHODS: In total, 83 SBA cases were selected from two European databases. The sequencing was performed using the Ion 316 Chip. Additionally we looked into ERBB2 expression and microsatellite instability (MSI) status.
RESULTS: The tumours most frequently were duodenal (47%) and stage ⩾3 (63%). Eight genes were mutated with a frequency >5%: KRAS, TP53, APC, SMAD4, PIK3CA, ERBB2, BRAF and FBXW7. ERBB2 alterations are present in 10 patients (12%) through mutations (7 cases) or amplifications (3 cases). ERBB2 mutations were significantly associated with duodenal tumour location (P=0.04). In this group, there was a positive association with dMMR status (P=0.006) and APC mutation (P=0.02) but negative association with p53 mutations (P=0.038).
CONCLUSIONS: This study describes the first large screening of somatic mutations in SBA using next generation sequencing. The ERBB2 mutation was revealed to be one of the most frequent alterations in SBA with a distribution dependent on tumour location. In most cases ERBB2 mutation was identical (p.L755S). In clinical practice, this may suggest that more than 10% of the patients with SBA could be treated using an anti-ERBB2-targeted agent.

Related: TP53

de Biase D, Cesari V, Visani M, et al.
High-sensitivity BRAF mutation analysis: BRAF V600E is acquired early during tumor development but is heterogeneously distributed in a subset of papillary thyroid carcinomas.
J Clin Endocrinol Metab. 2014; 99(8):E1530-8 [PubMed] Related Publications
CONTEXT: The homogeneous distribution of BRAF V600E in papillary thyroid carcinoma (PTC) has been called into question by recent reports. These studies claim that BRAF V600E is heterogeneous and is limited to tumor cell subsets in the majority of PTCs.
OBJECTIVE: The objective of the study was to understand the allele distribution of BRAF V600E by evaluating the percentage of mutated neoplastic cells in a group of PTCs using two different highly sensitive analytical approaches: allele-specific locked nucleic acid PCR and 454 next-generation sequencing targeted to BRAF exon 15.
STUDY DESIGN: BRAF V600E was investigated using allele-specific locked nucleic acid PCR on 155 consecutive samples of PTC. Mutated cases were reanalyzed by 454 next-generation sequencing and immunohistochemistry. Because the evaluation of genetic heterogeneity in tumor samples can be profoundly biased by contamination with normal cells, all mutation frequency data were normalized to the real amount of neoplastic cells within each tumor.
RESULTS: Eighty-five of 155 PTCs (54.8%) were BRAF V600E mutated. The distribution of mutated neoplastic cells within the tumor was as follows: greater than 80% in 37 of 85 (43.5%), 30-80% in 39 of 85 (45.9%), and less than 30% in 9 of 85 (10.6%). In most of the PTCs with less than 80% BRAF V600E-positive neoplastic cells, the mutation was present in large neoplastic cell subpopulations. Tumors with less than 30% mutated neoplastic cells were smaller than tumors with a percentage of mutated cells greater than 80% or between 30% and 80% (P < .05).
CONCLUSIONS: BRAF V600E is heterogeneously distributed in some PTCs. The large BRAF V600E neoplastic cell subpopulations found in mutated cases is consistent with the view that the BRAF V600E is acquired early during PTC development.

Related: Thyroid Cancer

Sideris M, Papagrigoriadis S
Molecular biomarkers and classification models in the evaluation of the prognosis of colorectal cancer.
Anticancer Res. 2014; 34(5):2061-8 [PubMed] Related Publications
Colorectal cancer (CRC) is the second leading cause of cancer-related death. Despite the progress that has been made towards the identification of the molecular mechanisms involved in CRC, currently there are many unclear points. The current opinion is that microsatellite instability (MSI), CpG island methylator phenotype (CIMP) and chromosomal instability (CIN) seem to play a significant role. MSI is related to point mutations in defect mismatch repair system of DNA. There are two well-established MSI phenotypes: MSI-high (MSI-H) and MSI-low (MSI-L or MSS). CIN refers to a different cellular event which originates from the presence of an abnormal chromosome complement or number. CIMP is the third most commonly involved event, and is defined by widespread methylation of CpG islands of suppressor promoters, with two phenotypes: CIMP-high and CIMP-low which interact with MSI or CIN status V-raf murine sarcoma viral oncogene homolog B (BRAF) is a serine-threonine protein kinase that acts as a downstream effector of the Kirsten rat sarcoma viral oncogene homolog (KRAS) pathway. Various studies have revealed that BRAF V600E mutations appear to be a valid indicator of poor prognosis. KRAS is a proto- oncogene which encodes a GTP-ase involved in cellular response to extracellular stimuli. Its prognostic value is still controversial. However, wild-type KRAS is associated with better response to Endothelial Growth Factor Receptor inhibitors combined with standard chemotherapy. Loss of Heterozygosity, especially involving 18q, is a well-known potential mechanism for tumorigenesis that has been studied in CRC. Vascular endothelial growth factor is a pro-angiogenic factor linked with the aggressiveness of CRC. Emerging data show that cycloxygenase 2 overexpression is significantly associated with worse outcomes in CRC. Recent studies highlight mi-croRNAs as promising prognostic biomarkers. More specifically, the down-regulation of miR-451, miR-625, miR-29c, miR-126, miR-129 and miR133 is purported to be a poor prognostic factor, while miR-224 was overexpressed in CRC.

Related: Colorectal (Bowel) Cancer

Rossi ED, Martini M, Straccia P, et al.
Thyroglossal duct cyst cancer most likely arises from a thyroid gland remnant.
Virchows Arch. 2014; 465(1):67-72 [PubMed] Related Publications
Thyroglossal duct cancer is a rare entity, occurring in 1.5 % of all thyroglossal duct cysts (TDC). A definitive consensus about its neoplastic origin has not been established as two contrasting theories exist, one proposing an origin in extra-thyroid remnants and the other a metastatic localization of a primary thyroid cancer. We compare morphological and molecular characteristics of both thyroglossal and thyroid carcinomas in a case series from our institute. We evaluated histology of 80 TDC. In 12 cases, prior cytological evaluation had been performed by liquid-based cytology (LBC). The BRAF gene was examined for mutations, and the histology of both thyroglossal duct and synchronous thyroid carcinoma was reevaluated. In 9 out of 80 (11 %) TDC cases, a papillary thyroid cancer (PTC) was diagnosed. In five out of nine (56 %) thyroglossal carcinomas, a synchronous thyroid cancer was diagnosed: 3 PTC and 2 follicular variant PTC (FVPC). In five thyroglossal carcinomas, mutated BRAF (V600E) was found, three in PTC and in thyroglossal as well as in the synchronous tumor in the thyroid. All the patients are in a disease-free status and still alive. Our results suggest that the majority of thyroglossal carcinomas most likely develop as a primary malignancy from a thyroid remnant. Neither the presence of V600E BRAF mutations nor that of a well-differentiated thyroid carcinoma changed the outcome or disease-free survival. We suggest that a diagnosis of thyroglossal carcinoma should be followed by a detailed evaluation of the thyroid gland. In the absence of clinical and radiological thyroid alterations, follow-up as for thyroid cancer is the correct management.

Related: Thyroid Cancer

Foletto MC, Haas SE
Cutaneous melanoma: new advances in treatment.
An Bras Dermatol. 2014 Mar-Apr; 89(2):301-10 [PubMed] Article available free on PMC after 01/09/2015 Related Publications
Cutaneous melanoma is a challenge to treat. Over the last 30 years, no drug or combination of drugs demonstrated significant impact to improve patient survival. From 1995 to 2000, the use of cytokines such as interferon and interleukin become treatment options. In 2011, new drugs were approved by the U.S. Food and Drug Administration, including peginterferon alfa-2b for patients with stage III disease, vemurafenib for patients with metastatic melanoma with the BRAF V600E mutation, and ipilimumab, a monoclonal antibody directed to the CTLA-4 T lymphocyte receptor, to combat metastatic melanoma in patients who do not have the BRAF V600E mutation. Both ipilimumab and vemurafenib showed results in terms of overall survival. Other trials with inhibitors of other genes, such as the KIT gene and MEK, are underway in the search for new discoveries. The discovery of new treatments for advanced or metastatic disease aims to relieve symptoms and improve patient quality of life.

Related: Monoclonal Antibodies Interleukin 2 (Aldesleukin) Melanoma Skin Cancer Vemurafenib (Zelboraf) Ipilimumab (Yervoy)

Musulén E, Sanz C, Muñoz-Mármol AM, Ariza A
Mismatch repair protein immunohistochemistry: a useful population screening strategy for Lynch syndrome.
Hum Pathol. 2014; 45(7):1388-96 [PubMed] Related Publications
Lynch syndrome (LS), the most frequent form of hereditary colorectal cancer, shows a highly penetrant, autosomal dominant pattern of inheritance. Distinction of LS colorectal carcinoma instances from the much more common sporadic colorectal carcinoma cases is of paramount importance. Revised Bethesda Guidelines were developed to diagnose LS by evaluating a combination of clinical and pathologic data. The aim of the present study was to evaluate the usefulness of the pathology items included in the Revised Bethesda Guidelines. We have prospectively studied a series of 1624 consecutive colorectal carcinomas with an algorithm including immunohistochemical analysis of mismatch repair proteins and molecular study of microsatellite instability and BRAF c.1799 T > A (p.V600E) gene mutations. Patients with tumors showing LS features were referred for germline mutation analysis. By applying our algorithmic approach, we were able to identify LS features in 89 colorectal cancer patients, of whom only 27 met Revised Bethesda Guidelines pathology criteria. Of the 89 patients, 47 were then studied at the Genetic Counseling Unit, and LS was confirmed in 18, of whom 7 had not been identified by the Revised Bethesda Guidelines. Our study shows that the Revised Bethesda Guidelines failed to detect 70% of patients at risk of LS. Our algorithmic approach is a realistic and effective tool for LS identification. We strongly recommend the implementation of universal population screening for LS among all patients with newly diagnosed colorectal carcinoma.

Related: Colorectal (Bowel) Cancer

Cornejo KM, Hutchinson L, Deng A, et al.
BRAF/KRAS gene sequencing of sebaceous neoplasms after mismatch repair protein analysis.
Hum Pathol. 2014; 45(6):1213-20 [PubMed] Related Publications
Sebaceous neoplasms are cutaneous markers for the autosomal-dominant Muir-Torre syndrome (MTS). This phenotypic variant of Lynch syndrome (LS) is caused by germline mutations in DNA mismatch repair (MMR) genes. Microsatellite instability or loss of protein expression suggests a mutation or promoter hypermethylation in 1 of the MMR genes. BRAF gene sequencing may help to distinguish between patients with sporadic and LS-associated colorectal carcinomas with loss of MLH1 expression. LS-associated carcinomas are virtually negative for BRAF mutations, but a subset harbors KRAS mutations. The aim of our study was to test sebaceous neoplasms for V600E BRAF or KRAS mutations to determine if these mutations are associated with somatic or germline MMR defects, analogous to colorectal carcinomas. Over a 4-year period, 32 cases comprising 21 sebaceous adenomas, 3 sebaceomas, and 8 sebaceous carcinomas with sufficient material for testing were collected. MMR immunohistochemistry showed that 7 neoplasms had combined loss of MLH1-PMS2, 16 neoplasms had combined loss of MSH2-MSH6, 2 neoplasms had solitary loss of MSH6, and 7 sebaceous neoplasms had intact protein expression. BRAF/KRAS testing revealed all sebaceous neoplasms contained a wild-type BRAF gene. Two (15%) of 13 patients with MTS were found to harbor a KRAS mutation and loss of MLH1 expression. We conclude that a V600E BRAF mutation may not be helpful in distinguishing sporadic from MTS-associated sebaceous neoplasms. Further studies are needed to determine if KRAS mutations are restricted to patients with MTS or are also present in sporadic sebaceous neoplasms.

Related: KRAS gene MLH1

Gomes CC, Diniz MG, Gomez RS
Progress towards personalized medicine for ameloblastoma.
J Pathol. 2014; 232(5):488-91 [PubMed] Related Publications
Ameloblastoma is a locally infiltrative benign odontogenic neoplasm. Tumours may be large, destructive and recurrent, requiring radical surgery with associated facial deformity and morbidity. The molecular pathogenesis of this tumour has been unclear, retarding the development of non-invasive gene-targeted therapies. In a recent paper in this journal, Kurppa et al. [4] showed that EGFR-targeted therapy blocked cell proliferation in an ameloblastoma primary cell culture. That this therapy was not effective in another primary cell culture led to the discovery of the oncogenic BRAF V600E mutation in a high proportion (63%) of ameloblastoma samples. By defining two separate pathways, both of which can be specifically targeted, these findings are an important step towards personalized medicine of ameloblastoma. We discuss the findings in the broader context of ameloblastoma, as well as the effects of tumour microenvironment and molecular heterogeneity that need to be taken into account when considering the use of personalized therapies based on specific genetic mutations in individual patients.


Found this page useful?

Disclaimer: This site is for educational purposes only; it can not be used in diagnosis or treatment.

Cite this page: Cotterill SJ. BRAF gene, Cancer Genetics Web: http://www.cancerindex.org/geneweb/BRAF.htm Accessed: date

Creative Commons License
This page in Cancer Genetics Web by Simon Cotterill is licensed under a Creative Commons Attribution-ShareAlike 4.0 International License.
Note: content of abstracts copyright of respective publishers - seek permission where appropriate.

 [Home]    Page last revised: 14 December, 2014     Cancer Genetics Web, Established 1999