Family history and survival after colorectal cancer diagnosis

Abstract

A history of colorectal cancer in a first-degree relative is a recognized risk factor for developing this malignancy. The influence of a family history of colorectal cancer on survival after a diagnosis of colorectal cancer was examined in a large cohort of women. We analyzed data from 1001 women diagnosed with colorectal cancer while participating in a prospective cohort study. Data on family history were obtained before cancer diagnosis. We computed Cox proportional hazards for cancer-specific and overall mortality according to a family history of colorectal cancer, adjusting for other predictors for survival. Before diagnosis, 16% of colorectal patients reported a history of colorectal cancer in a first-degree relative. Patients with a history of colorectal cancer in 1 or more first-degree relatives experienced an adjusted hazard ratio (HR) for overall mortality of 1.32 (95% confidence interval [CI], 1.01-1.72) and colorectal cancer-specific mortality of 1.38 (95% CI, 1.02-1.86) when compared with those without a family history. Moreover, patients with 2 or more affected relatives had an HR for overall mortality of 2.07 (95% CI, 1.14-3.76) and cancer-specific mortality of 2.19 (95% CI, 1.10-4.38). The significant deleterious effect of family history was limited to patients with advanced disease at presentation and cancers originating in the colon. Among women with colorectal cancer, a history of colorectal cancer in a first-degree relative was associated with a significant decrease in survival. Additional study is needed to validate these findings and determine whether specific germline polymorphisms correlate with clinical outcomes.