A follow-up strategy for patients with gallbladder polyps should be based on the size of the polyps, which can affect prognosis and the likelihood of cancer, suggest researchers from the United Kingdom. According to the results of a retrospective analysis completed by Giuseppe Garcea, MD, from the University Hospital of Leicester, UK, and colleagues at a tertiary care hepatobiliary center, polyps with a larger original diameter (7 mm) were more likely to increase in size during follow-up compared to polyps with a diameter of 5 mm (P<0.05). The results of the study, published online in the Archives of Surgery, also showed that polyps with an original diameter greater than 10 mm were more likely to be malignant or to be cancerous (area under the curve 0.81, P<0.001). The rarity of gallbladder polyps and incomplete knowledge of their formation, combined with the fact that most gallbladder polyps tend to be malignant and only a few are adenomatous, make it impossible to determine the best treatment option. In addition, ultrasound diagnosis of gallbladder polyps remains difficult, and many diagnosed as gallbladder polyps are actually stones or cholesterol polyps in the gallbladder wall. Therefore, Garcea and his research group retrospectively studied the medical histories of 986 patients at the center between 2000 and 2011 to determine which patients required surgical removal of the gallbladder, which patients required close follow-up monitoring, and which patients required only occasional or no follow-up. More than half of the patients included were women, with a mean age of slightly more than 57 years. The results showed that 69% of the polyps were less than 5 mm in diameter, 26.2% were between 5 and 10 mm in diameter, and the remainder were larger than 10 mm in diameter. 62% of the patients presented with a single polyp, and 24.4% had more than 3 polyps. The mean follow-up time was 39.3 months, but half of the patients did not continue monitoring or follow-up after this time. During the follow-up monitoring period, only 6.6% of the polyps increased in diameter, 25.7% became smaller, and 67.7% did not change in size. After cholecystectomy, only 3.7% of the specimens showed the possibility of malignancy on histological examination, and only one specimen showed actual cancer. The investigators concluded that there is a high potential cost-effectiveness of giving follow-up surveillance for the above types of polyps. The overall economic burden associated with gallbladder cancer in the United States is estimated to be $78 million per year. Assuming an average age of onset of gallbladder polyps of 57 years, a life expectancy of 20 years, and ultrasound exams every two years, this would cost $47,036 per year or $9.4 million over 20 years. The researchers further noted that if all of the polyps with probable neoplastic changes were malignant, biennial follow-up surveillance could save 5.4 lives per year. If, consistent with the retrospective study sample, 30% of the follow-up patients had surgery, the annual cost of surgery would be $253,115, or $310,167 per year if follow-up surveillance was added. If the annual cost per gallbladder cancer patient is $94,069, the projected savings from follow-up monitoring would be approximately $207,839 per 1,000 patients per year. The researchers also suggest that follow-up surveillance would be more cost-effective for only patients with polyps greater than or equal to 5 mm in diameter or for those at high risk of gallbladder malignancy, such as Asians. Jonathan Koea, MD, of North Shore Hospital in Auckland, New Zealand, also offered his personal opinion on the study in an invited review article, "Follow-up surveillance is more cost-effective when given at a higher incidence of adenomatous lesions in patients with polyps, but this is something that cannot yet be definitively diagnosed with current imaging techniques. " Garcea and his group concluded that polyps smaller than 5 mm are "almost negligible," while polyps larger than 10 mm or progressively larger should be cholecystectomized, and those between 5 and 10 mm should be followed up. They also noted, however, that almost half of the patients in the study were not followed up after the diagnosis of "potentially malignant" polyps. Therefore, they also suggest that polyps smaller than 10 mm should be surgically removed in younger patients who are not guaranteed long-term follow-up. Finally, the researchers suggest that "all gallbladder polyps that show a tendency to become malignant need to be discussed in meetings of the hepatobiliary team to enhance and standardize treatment options for this condition.