Why do Black Americans have a higher risk of pancreatic cancer than White Americans?

BACKGROUND: For several decades, the incidence of pancreatic cancer has been 50% to 90% higher among blacks than among whites in the United States. The purpose of this study was to identify risk factors that may contribute to this racial disparity.
METHODS: We conducted a population-based case-control study of pancreatic cancer diagnosed in Atlanta (GA), Detroit (MI), and 10 New Jersey counties from August 1986 through April 1989. In-person interviews were exclusively with subjects (526 cases and 2153 population controls), rather than with next of kin.
RESULTS: The determinants of the higher incidence of pancreatic cancer among blacks than among whites differed by sex. Among men, established risk factors (, cigarette smoking, long-term diabetes mellitus, family history of pancreatic cancer) account for 46% of the disease in blacks and 37% in whites, potentially explaining all but 6% of the excess risk among blacks. Among women, however, other factors appear to contribute to the racial disparity, notably moderate/heavy alcohol consumption (>7 drinks per week) and elevated body mass index (above the first quartile). When these less accepted risk factors were combined with the established risk factors, 88% of the disease in black women and 47% in white women were explained, potentially accounting for all of the excess risk among blacks in our female study population.
CONCLUSIONS: Among men, the established risk factors (mainly cigarette smoking and diabetes mellitus) explain almost the entire black/white disparity in incidence. Among women, however, other factors appear to contribute to the racial disparity, notably moderate/heavy alcohol consumption and elevated body mass index. In the absence of these factors, pancreatic cancer incidence rates among blacks probably would not exceed those among whites of either sex.