Cancer risk among the relatives of patients with pancreatic ductal adenocarcinoma.

BACKGROUND/AIMS: Pancreatic cancer is a leading cause of cancer-related death; the most consistently identified risk factors are smoking and family history. Our aims were to examine familial aggregations of pancreas and other cancers, and to determine the relative risk of the family members. METHODS: We prospectively collected data on the families of patients presenting with pancreatic ductal adenocarcinoma. Smoking habits and alcohol consumption of the probands were compared with the available statistics on the Italian population. Mortality from cancer was investigated in first-degree relatives, and age-dependent risks of dying from pancreatic cancer and other tumors were compared with background population levels. RESULTS: Data for 570 families were collected, including 9,204 relatives. Probands were 3- to 5-fold more often heavy smokers than the general population, and 9.3% of them reported a positive family history of pancreatic cancer. In first-degree relatives, only mortality from pancreatic cancer was significantly increased (relative risk at age 85 years = 2.7). Lifetime risk of dying of pancreas cancer was 4.1% for the relatives of all probands, and was 7.2% for the relatives of probands who developed disease before 60 years of age. CONCLUSIONS: The data suggest that genetic susceptibility to pancreatic cancer may be attributable, in addition to BRCA2, to moderate- to low-penetrance gene(s).