The prognostic role of BRAF mutation in metastatic colorectal cancer receiving anti-EGFR monoclonal antibodies: a meta-analysis

PLoS One. 2013 Jun 11;8(6):e65995. doi: 10.1371/journal.pone.0065995. Print 2013.

Abstract

Background: BRAF mutation has been investigated as a prognostic factor in metastatic colorectal cancer (mCRC) undergoing anti-EGFR monoclonal antibodies (moAbs), but current results are still inconclusive. The aim of this meta-analysis was to evaluate the relationship between BRAF mutation status and the prognosis of mCRC patients treated with moAbs.

Methods: Eligible studies were identified by systematically searching Pubmed, the Cochrane Library, Web of Knowledge, and OVID. Risk ratio (RR) for overall response rate (ORR), Hazard ratios (HRs) for Progression free survival (PFS) and Overall survival (OS) were extracted or calculated. Prespecified subgroup analyses were conducted in KRAS wild-type and in different study types. The source of between-trial variation was explored by sensitivity analyses. Quality assessment was conducted by the Hayden's criteria.

Results: A total of twenty one trials including 5229 patients were identified for the meta-analysis. 343 patients displayed BRAF mutations of 4616 (7.4%) patients with known BRAF status. Patients with BRAF wild-type (WT) showed decreased risks of progression and death with an improved PFS(HR 0.38, 95% confidence intervals 0.29-0.51) and an improved OS (HR 0.35 [0.29-0.42]), compared to BRAF mutant. In KRAS WT population, there were even larger PFS benefit (HR 0.29[0.19,0.43]) and larger OS benefit (HR 0.26 [0.20,0.35]) in BRAF WT. A response benefit for BRAF WT was observed (RR 0.31[0.18,0.53]) in KRAS WT patients, but not observed in unselected patients (RR 0.76 [0.43-1.33]). The results were consistent in the subgroup analysis of different study types. Heterogeneity between trials decreased in the subgroup and explained by sensitivity analysis. No publication bias of ORR, PFS and OS were detected.

Conclusions: The results indicate that BRAF mutant is a predictive biomarker for poor prognosis in mCRC patients undergoing anti-EGFR MoAbs therapy, especially in KRAS WT patients. Additional large prospective trials are required to confirm the predictive role of BRAF status.

Publication types

  • Meta-Analysis
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Antibodies, Monoclonal / immunology
  • Antibodies, Monoclonal / therapeutic use*
  • Biomarkers
  • Colorectal Neoplasms / drug therapy*
  • Colorectal Neoplasms / genetics
  • ErbB Receptors / antagonists & inhibitors*
  • ErbB Receptors / immunology
  • Humans
  • Mutation
  • Proto-Oncogene Proteins B-raf / genetics*

Substances

  • Antibodies, Monoclonal
  • Biomarkers
  • ErbB Receptors
  • BRAF protein, human
  • Proto-Oncogene Proteins B-raf

Grants and funding

The study was supported by National Natural Science Foundation of China (NSFC) (grant no. 81072042, URL: http://www.gov.cn/banshi/qy/rlzy/2005-09/03/content_29011.htm) and supported by Chinese Ministry of Education’s “Doctor Station” Foundation (grant no. 20120171110096, URL: http://www.moe.edu.cn/). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.