Hormonal exposure and risk of pancreatic cancer in the United States

Background. In the United States, the incidence of pancreatic cancer has increased; more than 37,000 new cases of pancreatic cancer were diagnosed in the year 2007. Overall, the five-year survival rate is about 5% and pancreatic cancer ranks the fourth leading cause of cancer-related mortality among men and women. Despite the observed progress in cancer diagnosis and treatment, pancreatic cancer remains an unresolved significant public health problem in the United States. Familial pancreatic cancer has been confirmed to be responsible for approximately 10% of pancreatic cancer cases. However, 90% are still without known inherited predisposition. Until now, the role of oral contraceptive pills (OCPs) and hormonal replacement therapy (HRT) among women with pancreatic cancer remain unclear. We examined the association of exogenous hormonal uses in US women with risk of pancreatic cancer. ^ Methods. This was an active hospital-based case-control study which is conducted at the department of gastrointestinal medical oncology in The University of Texas M.D. Anderson Cancer Center. Between January 2005 and December 2007, a total of 287 women with pathologically confirmed pancreatic cancer (cases) and 287 healthy women (controls) were included in this investigation. Both cases and controls were frequency matched by age and race. Information about the use of hormonal contraceptives and hormonal replacement therapy (HRT) preparations as well as information about several risk factors of pancreatic cancer were collected by personal interview. Univariate and multivariate analyses were performed in this study to analyze the data. ^ Results. We found a statistical significant protective effect for use of exogenous hormone preparations on pancreatic cancer development (adjusted odds ratio [AOR], 0.4; 95% confidence interval [CI], 0.2–0.8). In addition, a 40% reduction in pancreatic cancer risk was observed among women who ever used any of the contraceptive methods including oral contraceptive pills (AOR, 6; 95% CI, 0.4–0.9). ^ Conclusions. Consistent with previous studies, the use of exogenous hormone preparations including oral contraceptive pills may confers a protective effect for pancreatic cancer development. More studies are warranted to explore for the underlying mechanism of such protection.