BRAF mutation increased mortality risk in melanoma, colorectal cancer patients
BRAF mutation was a risk factor for survival among patients with melanoma and patients with colorectal cancer, according to study results.
Researchers gathered clinical studies correlating BRAF mutation and patient survival from Medline and Embase databases between June 2002 and December 2011. They searched for the terms “BRAF,” “BRAF mutation,” “BRAF V600E,” “cancer,” “patient survival,” “colorectal cancer,” “melanoma” and “papillary thyroid carcinoma” in various combinations. Contingent on study design and cancer type, 120 relevant studies were categorized, with publication bias evaluated for each study. Random or fixed-effect meta-analysis based on percentage of heterogeneity was used to calculate pooled hazard ratios.
Final meta-analysis included 26 studies on colorectal cancer (five randomized control trials [RCTs], 21 cohorts; 11,773 patients) and four studies on melanoma (one RCT, three cohorts; 674 patients). Meta-analysis was not performed on papillary thyroid carcinoma for lack of study numbers.
In the reports, BRAF mutation prevalence averaged 47.8% for melanoma and 9.6% for patients with colorectal cancer. With BRAF mutation, mortality risk in patients with melanoma revealed a final pooled log of 0.53 (95% CI, 0.32-0.75), translating to an increased HR of 1.70 (95% CI, 1.37-2.12). Among patients with colorectal cancer, final log HR across all studies was 0.81 (95% CI, 0.60-1.03), which corresponded to a risk that more than doubled (HR=2.24; 95% CI, 1.82-2.83) when BRAF mutation was present.
“BRAF plays a very important role in cancer initiation and progression,” the researchers said. “[These data highlight] the important role of mutant BRAF in patient survival and suggest that with successful BRAF inhibition we may be able to increase the survival of colorectal cancer and melanoma patients harboring BRAF mutation.”