Risk of pancreatic cancer among individuals with a family history of cancer of the pancreas.

In a hospital based case-control study of pancreatic cancer in Ontario and Quebec, a total of 174 incident pancreatic cancer cases and 136 healthy controls were compared for their family history of cancer. Information regarding the ages and sites of cancer was taken for 966 first-degree relatives of the cancer cases and for 903 first-degree relatives of the controls. A total of 150 cancer cases were reported among the relatives of the cases, compared to 122 cases among the relatives of the controls (relative risk 1.15; p = 0.23). Pancreatic cancer was the only site statistically in excess in the case relatives, compared to the control relatives (relative risk = 5.0; p = 0.01). The lifetime risk of pancreatic cancer was 4.7% for the first-degree relatives of the pancreatic cancer cases. The risk was 7.2% for relatives of cases diagnosed before age 60, and was 12.3% for relatives of patients with multiple primary cancers (all ages). These individuals comprise a high-risk group for pancreatic cancer and might benefit from enhanced surveillance or chemoprevention. Familial site-specific pancreatic cancer appears to be a distinct genetic entity, but contributes only modestly to the total burden of pancreatic cancer.