Radical resection for T1b gallbladder cancer: a decision analysis

Background: Gallbladder cancer is the most common malignancy of the biliary tract. Radical surgery (including liver resection and regional lymphadenectomy) is applied for some gallbladder cancers, but the benefits of these procedures are unproven. For patients with T1b cancers discovered incidentally on cholecystectomy specimens, the utility of radical surgery remains debated. Methods: A decision analytic Markov model was created to estimate and compare life expectancy associated with management strategies for a simulated cohort of patients with incidentally discovered T1b gallbladder cancer after routine cholecystectomy. In one strategy, patients were treated with no additional surgery; in another, patients were treated with radical resection. The primary (base-case) analysis was calculated based on a cohort of 71-year-old females and incorporated best available input estimates of survival and surgical mortality from the literature. Sensitivity analysis was performed to assess the effects of model uncertainty on outcomes. Results: In the base-case analysis, radical resection was favoured over no further surgical resection, providing a survival benefit of 3.43 years for patients undergoing radical resection vs. simple cholecystectomy alone. Sensitivity analysis on the age at diagnosis demonstrated that the greatest benefit in gained life-years was achieved for the youngest ages having radical resection, with this benefit gradually decreasing with increasing age of the patient. High peri-operative mortality rates (>= 36%) led to a change in the preferred strategy to simple cholecystectomy alone. Conclusions: Decision analysis demonstrates that radical resection is associated with increased survival for most patients with T1b gallbladder cancer.