Risk of gallbladder cancer in patients with primary sclerosing cholangitis and radiographically detected gallbladder polyps.

Abstract

Primary sclerosing cholangitis (PSC) is associated with an increased risk of gallbladder cancer (GBC). Gallbladder polyps potentially harbour malignancy and thus international guidelines recommend prophylactic cholecystectomy for gallbladder polyps of any size in patients with PSC. To best inform patient care we sought to quantify the malignant risk of gallbladder polyps in patients with PSC. A retrospective cohort study of patients followed in secondary and tertiary care settings in two large PSC clinics in North America was performed. In total, 453 patients were included with a median (IQR) follow-up time of 7.7 (4.1-12) years. A gallbladder polyp was radiographically detected in 16% (n=71) with median size (range) of 4 (2-18) mm. In this group, post-cholecystectomy histology (n=17) reported benign or no polyp in 77% (n=13), dysplasia in 5.9% (n=1) and malignancy in 18% (n=3). The GBC rate was 8.8 (95% CI 1.8-25.7) per 1000 person-years in patients with a radiographically detected gallbladder polyp. GBC was associated with polyps >10mm, interval growth or mass-like lesions on pre-operative imaging. In patients who did not have cholecystectomy (n=50), the polyp was only transiently seen in 80% (n=40), remained stable or decreased in size in 10% (n=5) and increased in size in 6% (n=3). The majority of gallbladder polyps did not show significant growth over time (0.041mm/year [95% CI -0.017 to 0.249]). Most gallbladder polyps in patients with PSC are benign. Short-term surveillance imaging may be considered prior to recommending immediate cholecystectomy in patients with PSC without high-risk imaging features.