Risk factors analysis of malignancy from gallbladder polyps

Objective To investigate the risk factors of malignancy from gallbladder polyps (GBPs). Methods The retrospective case-control study was conducted. The clinicopathological data of 604 patients with GBPs who were admitted to the Chinese PLA General Hospital between January 2011 and October 2016 were collected. There were 255 males and 349 females, aged from 19 to 88 years, with an average age of 47 years. There were 565 of 604 patients with benign GBPs and 39 with malignant GBPs. Observation indicators: (1) risk factors analysis of malignancy from GBPs; (2) the predictive ability of polyp diameter for malignancy from GBPs. Measurement data with normal distribution were expressed as Mean±SD, measurement data with skewed distribution were described as M (range), and the univariate analysis was done using the t test or rank-sum test. Count data were described by the absolute amount, and the univariate analysis was done using the chi-square test or Fisher exact probability. The indicators with P<0.05 in the univariate analysis based on clinical application were used in the Logistic regression models for multivariate analysis. The receiver operating characteristic (ROC) curve was drawn. The Youden index was calculated to analyze the predictive ability of polyp diameter for malignancy from GBPs. Results (1) Risk factors analysis of malignancy from GBPs: results of univariate analysis showed that age, polyp diameter, polyp number, chronic cholecystitis and carcinoembryonic antigen (CEA) level were related factors affecting malignancy from GBPs (t=-5.50, Z=-9.65, χ2=15.92, 312.65, Z=-1.78, P<0.05). The results of multivariate analysis showed that age, polyp diameter and polyp number were independent factors affecting malignancy from GBPs (odds ratio=1.088, 45.190, 9.655, 95% confidence interval: 0.974-1.159, 4.312-121.139, 0.890-117.551, P<0.05). (2) The predictive ability of polyp diameter for malignancy from GBPs. The sensitivity and specificity predicting malignancy from GBPs were 94.9% and 81.2% in patients with polyp diameter=10 mm and Youden index=0.761, 89.7% and 90.6% in patients with polyp diameter=12 mm and Youden index=0.803, 84.6% and 92.6% in patients with polyp diameter=13 mm and Youden index=0.772, respectively. Conclusions The age, polyp diameter and polyp number are the independant factors affecting malignancy from GBPs. The malignancy possibility from GBPs is higher in patients with the age > 50 years, polyp diameter >12 mm, solitary polyp, and should undergo surgical therapy actively. Key words: Gallbladder neoplasms; Gallbladder polyps; Malignancy; Risk factors; Cholecystectomy