Cholelithiasis and pancreatic cancer. A case-control study.

To study the possible association between pancreatic cancer and cholelithiasis, we conducted a retrospective case-control study. Abdominal ultrasound of 100 consecutive cases of pancreatic cancer and that of 140 age- and gender-matched control subjects were examined by 2 observers who did not know the diagnosis. Thirty-seven patients with pancreatic cancer had cholelithiasis (37%), as compared with 23 (16%) of the control group (p < 0.001). The increased prevalence of gallstones in patients with pancreatic carcinoma remained significant when either male or female patients were compared (p < 0.02), as well as in the various age groups studied. For example, 30 (43.5%) of 69 patients 65 years of age and older had cholelithiasis versus 21 (22%) of 95 control subjects (p < 0.005). Thus, patients with pancreatic cancer were found to have a higher prevalence of gallstone disease than expected in a matched control population (relative risk, 2.2; 95% confidence interval, 1.2-4.3). This finding does not establish a causal link; however, the possibility should be pursued, more so because gallstones have been identified previously as likely risk factors for cancer in other parts of the biliary-pancreatic tract.