Influence of a family history of cancer within and across multiple sites on patterns of cancer mortality risk for women

A case-control study nested within a large cohort, the American Cancer Soci ety Cancer Prevention Study-1, was conducted to test associations between a family history of cancer and cancer mortality in women. By using logistic regression, the authors analyzed family history, as reported by 429,483 wom en enrolled in 1959, relative to subsequent mortality through 1972 from can cer within and across multiple sites. The associations between family histo ry and cancer mortality were generally stronger within cancer sites than ac ross cancer sites. Within-site associations were found for breast cancer (o dds ratio (OR) = 1.9), colorectal cancer (OR = 1.6), stomach cancer (OR = 1 .9), and lung cancer (OR = 1.7). Across-site associations were observed for a family history of 1) breast cancer as a risk factor for ovarian cancer m ortality (OR = 1.6), 2) stomach cancer as a risk factor for ovarian cancer mortality (OR = 1.5), and 3) uterine cancer as a risk factor for pancreatic cancer mortality (OR = 1.6), A general pattern of positive associations wa s observed between a family history of cancer at several sites and subseque nt death from pancreatic cancer. These findings support the growing body of evidence from cancer genetics suggesting that inherited cancer-susceptibil ity genes increase the risk for cancer at many sites and are not specific t o cancer risk within a single site.