Surveillance for Gallbladder Polyps

Up to 95% of lesions seen on ultrasonography (USS) are benign. Certain polyps, in particular adenomas of the gallbladder, may carry neoplastic potential, according to researchers. Although these represent the minority of gallbladder polyps, the poor survival rate from gallbladder cancer mandates their removal.

Because the majority of gallbladder polyps are benign, there are no clear guidelines to best manage gallbladder polyps, including which polyps to survey and which to resect. Researchers recently conducted a retrospective case-note analysis of a large series of sonographically detected polyps to determine the indications for cholecystectomy, surveillance, or no follow-up. The researchers also desired to determine whether surveillance of polyps is cost-effective. They reported results of the analysis in Archives of Surgery [2012;147(12):1078-1083].

The analysis utilized data from a tertiary referral teaching hospital practice. All patients coded with gallbladder polyps on radiologic records from a computerized database from 2000 to 2011 were identified. Case notes were retrieved and demographic data were recorded. The number of scans, scan intervals, size of polyps, number of polyps, and progression of these parameters over further follow-up were recorded as well.

The main outcome measures of the analysis were detection rates for potentially neoplastic and frankly neoplastic polyps, which were compared with complication rates from cholecystectomy. Cost-effectiveness of ultrasonography surveillance was also assessed.

A total of 986 patients were identified from medical records with a median follow-up of 39.3 months. Median age was 57.1 years (range, 35-74 years), and 54.9% were female. Approximately half (48.1%) of polyps were detected from USS undertaken for upper abdominal pain; the majority of the remainder were incidental findings. The majority of the detected polyps were <5 mm (69.0%); polyps >20 or 30 mm were very rare (0.5% and 0.1%, respectively).

There was rarely a discussion of polyps at a specialist hepatobiliary multidisciplinary meeting; 49.6% of all patients diagnosed with gallbladder polyps did not have any follow-up. Of the polyps under surveillance, the majority had no increase in size (67.7%) or number (58.0%).

During the surveillance period, only 6.6% of polyps exhibited an increase in size. Those that substantially increased in size during the surveillance period were significantly greater in diameter at initial presentation compared with those that remained static (7 mm vs 5 mm, respectively; P<.05).

Pain or polyp size >10 mm were the most common indicators for surgery. On histologic analysis, stone disease formed a significant number of all final diagnoses (16.4%). Of the gallbladders removed, 96.4% were benign; only 3.7% had “frankly malignant or potentially malignant conditions,” according to the researchers.

There were significant differences in size progression (P<.001), absolute size (P<.001), and duration of follow-up (P=.001) between patients with benign disease at cholecystectomy and patients with malignant or potentially malignant disease. The specimens with malignancy or potential malignancy had a median size of 10 mm, with a median follow-up prior to surgery of 21.4 months.

Analysis of the cost of surveillance found that a surveillance with or without selective surgery policy could potentially detect and prevent 5.4 gallbladder cancers per 1000 per year with a cost savings of >$201,676 per year.

The researchers concluded by noting that, “Cancer prevention risks would exceed the risk ratios from cholecystectomy complications. Polyps >10 mm should be resected; those between 5 and 10 mm should be under ultrasonography surveillance.”