BRCA1 and BRCA2 Gene Mutations and Colorectal Cancer Risk

Systematic Review and Meta-analysis

Mok Oh; Ali McBride; Seongseok Yun; Sandipan Bhattacharjee; Marion Slack; Jennifer R. Martin; Joanne Jeter; Ivo Abraham


J Natl Cancer Inst. 2018;110(11):1178-1189. 

In This Article


Study Selection

Our initial literature search yielded a total of 442 relevant abstracts from PubMed, 616 relevant abstracts from Embase, and 12 relevant abstracts from Cochrane Library (Figure 2). An additional 12 records were identified by reviewing the reference lists of articles retrieved in the Scopus search or known to the authors. ProQuest was searched for theses and dissertations and none were found. After removing duplicates, 949 records were screened. A total of 917 publications were excluded based on abstracts review, leaving 32 publications assessed in full text. Of these, 14 were excluded: 10 publications did not include an incidence rate for colorectal cancer, one was an editorial, one study was a review paper, and two publications did not include information on BRCA mutation. A total of 18 separate studies were retained for the systematic review. Four of these studies were omitted from the meta-analysis: two did not include sufficient statistical information to compute an effect size, and two were kin–cohort studies using frequency of family history of colorectal cancer as an outcome.

Figure 2.

Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) flow diagram.