Further analysis indicated that 2R/2R (OR = 1.94, 95%CI = 1.26–2.95, P = 0.0096) and 2R/1R (OR = 1.58, 95%CI = 1.11–2.26, P = 0.0388) were associated with increased risk but 1R/1R (OR = 0.55, 95%CI = 0.35–0.84, P = 0.0196) and 1R/0R (OR = 0, 95%CI = 0–0.29, P = 0.0012) were associated with decreased risk in cancer-affected BRCA1+ group; 2R/1R (OR = 1.94, 95%CI = 1.14–3.32, P = 0.0242) was associated with increased risk in cancer-affected BRCA2+ group. This evidence concerns the gene BRCA1 and cancer.