The risk of gallbladder cancer from polyps in a large multiethnic series.

Background: The aim of this study is assess whether patients with Indian ethnic background are at an increased risk of developing gallbladder cancer (GBC) if they have been diagnosed with ultrasonic abnormalities of the gallbladder.

Methods: Between January 1998 and July 2006, 137,655 abdominal ultrasound examinations were performed in Leeds Teaching Hospitals NHS Trust. After the exclusion of repeat scans and those performed for renal or pelvic disease, 71,431 reports were included in this analysis. Patients in whom the diagnosis of GBC has been made without histology have been identified from the database of Northern and Yorkshire Cancer Registry and the presence of GBC was correlated with ultrasonic gallbladder abnormalities.

Results: Gallbladder polyps (GBP) were detected in 3.3% of patients and these were larger than 10 mm in 0.1% of the cases. Age above 60 years, Indian ethnic background, single GBP larger than 10mm, the presence of gallstones, severe gallbladder wall thickening and irregular thickening were independently associated with the higher odds of developing GBC. The prevalence of malignancy in those with GBP was significantly higher among patients with Indian ethnic background compared to Caucasian patients, 5.5% versus 0.08%, p<0.001.

Conclusions: The presence of GBP, irrelevant of size, amongst patients of Indian ethnic decent, is an indication for further investigation and/or cholecystectomy.