Ultrasonographic evidence of association of polyps and stones with gallbladder cancer

Objective: The purpose of this study was to evaluate the level of gallbladd er cancer risk associated with polyps and stones of the gallbladder by ultr asound examinations, Methods: We investigated abdominal ultrasonographic fi ndings for gallstones and polyps of the gallbladder and the relationship of these findings to malignancy in 194,767 asymptomatic participants in healt h screening examinations. Results: Gallstones were detected in 7,985 partic ipants (4.1%), at a prevalence of 5.3% in male and 4.5% in female participa nts. The prevalence was highest in the participants' seventh decade, follow ed by the sixth and the fifth decades, in both male and female participants . Polyps were found in 10,926 (5.6%), at a prevalence of 6.9% in the male a nd 4.5% in the female participants. In the male participants, prevalence wa s highest in the fourth decade, followed by the third and the fifth decades , whereas in the female participants it was highest in the fifth decade, fo llowed by the fourth and third, High prevalence of polyps greater than or e qual to 10 mm in diameter was found in the fifth to seventh decades in both sexes. Nineteen participants (0.01%) were diagnosed as having gallbladder cancer, and many of them were in the sixth or seventh decade in both sexes, Patients with stones showed a higher prevalence of gallbladder cancer. Thi s difference was shown to be statistically significant by age-adjusted anal ysis (p < 0.01). The age distribution of the participants with polyps great er than or equal to 10 mm in diameter was correlated with that of patients diagnosed with gallbladder cancer. Furthermore, polyp incidence was signifi cantly related to cancer by statistical analysis (p < 0.01). Conclusion: Th ese results suggest an association between gallstone or polyp of the gallbl adder and increased risk of malignancy, implying that an etiological associ ation may also exist. (Am J Gastroenterol 1999;94:446-450. (C) 1999 by Am. Coll. of Gastroenterology).