373 Long-Term Outcome of Gallbladder Polyps in Patients With Primary Sclerosing Cholangitis

Abstract

Background and Aims: Gallbladder (GB) polyps in PSC patients have a risk of malignancy. Recently, European Association for the study of the liver (EASL) guideline recommends cholecystectomy for GB polyp at any size in patients with PSC without strong evidences of back-up studies. We aimed to evaluate the predictors and long-term outcomes of PSC patients with GB polyps for developing malignancy. Methods: We identified 86 patients with PSC and GB polyp using HICDA codes (05756-21 with 05760-31) and radiological diagnosis codes of GB polyp/mass (760.3104) at the Mayo Clinic, Rochester, MN between January 1, 2000 and August 31, 2009. Twenty-six patients were excluded due to the indefinite diagnosis of PSC or GB polyp (n=22), known cases of cholangiocarcinoma (n=2) and no follow up data (n=2). Clinical information and pathological findings of GB polyps were reviewed. GB polyp was defined by at least two serial reports of radiological diagnosis. The estimated size of small GB polyp was 0.2 cm. Results: Of the 2281 patients with PSC, 60 patients (2.6%) were diagnosed as GB polyp with median age (interquartile range; IQR) of 49.8 years (39.3, 58.6) and 67% of them were male. Median (IQR) Mayo risk score at baseline were 0.33 (-0.11, 1.36). At baseline, 35.7% of patients had GB polyps of at least 2 polyps and 70% of patients had GB polyp with size of less than 0.6 cm. Thirty-one patients (52%) were subsequent received cholecystectomy. Eight of 60 patients (13.3%) develop GB cancer (n=8) while 2 patients had GB dysplasia. No patients without cholecystectomy develop malignant GB lesion during the median (IQR) duration of follow up of 44 (17.5, 84.3) months. By univariate analysis, patients with malignant GB lesions had significantly less frequent number of GB polyp of less than 0.6 cm at first diagnosis and at the last follow up, larger size of GB polyps at first diagnosis and at the last follow up than those with benign GB lesions. By a multivariable logistic analysis, the size of GB polyps at the last follow up was associated with malignant GB lesions (OR= 8.9; 95%CI 2.6-30.3). By using the ROC curve, the GB polyp' size ≥ 1.0 cm had a sensitivity of 99%, specificity of 94%, a negative predictive value of 99% and a positive predictive value of 77%, with an area under the curve of 98% for predicting malignant GB lesion. At the end of follow up, 6 patients (10%) died and 9 patients (15%) received liver transplantation. Conclusions: Thirteen percent of GB polyps in patients with PSC develop GB cancer. The size of GB polyps of at least 1.0 cm at the last follow up was a good predictor for malignant GB lesion.