Moreover, a 47-year-old female with a recurrent adenocarcinoma and a BRAF V600E mutation exhibited tumor regression after a fourth line therapy with dabrafenib and trametinib, targeting agents against BRAF mutations.
Patients (<i>n</i> = 59) from 24 centres were included: 57.6% men; mean age: 64.5 ± 14.5 years; 82% with a performance status of 0-1 at diagnosis; smoking status: 40.3% current, 32.6% former; 93% with adenocarcinoma histology; 75% stage iv; 78% with V600E mutations; 2 with <i>EGFR</i> and 2 with <i>ALK</i> co-mutations.
IHC cytoplasmic expression of BRAF V600E (VE1) protein was found in two of 95 cases: one case of adenocarcinoma NOS (one of three; 33%) and one case of carcinoma ex pleomorphic adenoma (one of five; 20%).
None of the MMRD small bowel adenocarcinomas harbored the BRAF V600E mutation, whereas 60% of MMRD colorectal carcinomas were positive for BRAF V600E with concurrent loss of MLH1 and PMS2 expression.
In addition, MC had a higher MMRd rate (0.892, 95% CI 0.758-0.956), higher BRAF(V600E) mutation rate (0.652, 95% CI 0.143-0.954) and lower KRAS mutation rate (0.171, 95% CI 0.065-0.378) than PDA/UDA and conventional adenocarcinoma.
Twenty-one BRAF mutations were identified in 951 patients with adenocarcinomas (2.2%; 95% confidence interval [CI], 1.4%-3.4%): 17 (81%; 95% CI, 60%-92%) were BRAF(V600E) mutations, and 4 were non-BRAF(V600E) mutations.
Median age was 63 years (range 42-85); gender was balanced; 14 (40%) were never smokers; all (100%) had adenocarcinoma; 29 (83%) had V600E; 6 (17%) had other mutations; one of them had a concomitant KRAS mutation.
Somatic BRAF mutations have been reported in 1-4% of non-small cell lung cancer (NSCLC), primarily in adenocarcinomas with the BRAF (V600E) mutation in about 50% of the cases.
CIMP(+) was detected in 27 of 99 (27.3%) duodenal adenocarcinomas and was associated with MSI (P = 0.011) and MLH1 methylation (P < 0.001), but not with KRAS mutations (P = 0.114), as compared with CIMP(-) tumors.No BRAF V600E mutation was detected.
BRAF V600E mutation and CpG island methylation phenotype-positive status are similar in signet ring cell carcinoma and mucinous adenocarcinoma but more frequent when compared with conventional adenocarcinoma.
Of the 259 proximal colon adenocarcinomas analyzed for mismatch repair protein abnormalities and/or MSI, 181 proximal colonic adenocarcinomas demonstrated proficient DNA mismatch repair using either MSI PCR (n=78), mismatch repair protein immunohistochemistry (n=91), or both MSI PCR and mismatch repair immunohistochemistry (n=12); these were tested for the BRAF V600E mutation and KRAS mutations.
Adenocarcinomas with this clinicopathologic phenotype may be worthwhile investigating for BRAF-V600E mutation as more genetically oriented drug therapies emerge.
The V600E mutation of the B-RAF gene was analyzed using allele-specific polymerase chain reaction in 79 archival prostatic adenocarcinomas (pT1aG1 to pT3cG3, median Gleason score 6); exons 11 and 15 were sequenced.