Risk of other cancers in individuals with a family history of pancreas cancer

Abstract

Background: Inherited predisposition to pancreas cancer accounts for approximately 10% of cases. Familial aggregation may be influenced by shared environmental factors and shared genes. We evaluate whether a family history of pancreas cancer is a risk factor for ten specified cancers in first-degree relatives: bladder, breast, colon, head and neck, lung, lymphoma, melanoma, ovary, pancreas, and prostate.

Methods: Risk factor data and cancer family history were obtained for 1,816 first-degree relatives of pancreas cancer case probands (n = 247) and 3,157 first-degree relatives of control probands (n = 420). Unconditional logistic regression models using generalized estimating equations were used to estimate odds ratios (ORs), and 95% confidence intervals of having a first-degree relative a specified cancer.

Results: A family history of pancreas cancer was associated with a doubled risk of lymphoma (OR = 2.83, 95% CI = 1.02-7.86) and ovarian cancer (OR = 2.25, 95% CI = 0.77-6.60) among relatives after adjustment. Relatives with a family history of early-onset pancreas cancer in a proband had a sevenfold increased risk of lymphoma (OR = 7.31, 95% CI = 1.45 to 36.7). Relatives who ever smoked and had a family history of pancreas cancer had a fivefold increased risk of ovarian cancer (OR = 4.89, 95% CI = 1.16-20.6).

Conclusion: Family history assessment of cancer risk should include all cancers. Assessment of other known and suspected risk factors in relatives will improve risk evaluation. As screening and surveillance methods are developed, identifying those at highest risk is crucial for a successful screening program.