Association of Optimal Time Interval to Re-resection for Incidental Gallbladder Cancer With Overall Survival A Multi-Institution Analysis From the US Extrahepatic Biliary Malignancy Consortium

IMPORTANCE The current recommendation is to perform re-resection for select patients with incidentally discovered gallbladder cancer. The optimal time interval for re-resection for both patient selection and long-term survival is not known. OBJECTIVE To assess the association of time interval from the initial cholecystectomy to reoperation with overall survival. DESIGN, SETTING, AND PARTICIPANTS This cohort study was conducted from January 1, 2000, to December 31, 2014 at 10 US academic institutions. A total of 207 patients with incidentally discovered gallbladder cancer who underwent reoperation and had available data on the date of their initial cholecystectomy were included. EXPOSURES Time interval from the initial cholecystectomy to reoperation: group A: less than 4 weeks; group B: 4 to 8 weeks; and group C: greater than 8 weeks. MAIN OUTCOMES AND MEASURES Primary outcome was overall survival. RESULTS Of 449 patients with gallbladder cancer, 207 cases (46%) were discovered incidentally and underwent reoperation at 3 different time intervals from the date of the original cholecystectomy: group A: less than 4 weeks (25 patients, 12%); B: 4 to 8 weeks (91 patients, 44%); C: more than 8 weeks (91 patients, 44%). The mean (SD) ages of patients in groups A, B, and C were 65 (9), 64 (11), and 66 (12) years, respectively. All groups were similar for baseline demographics, extent of resection, presence of residual disease, T stage, resection margin status, lymph node involvement, and postoperative complications. Patients who underwent reoperation between 4 and 8 weeks had the longest median overall survival (group B: 40.4 months) compared with those who underwent early (group A: 17.4 months) or late (group C: 22.4 months) reoperation (log-rank P =.03). Group A and C time intervals (vs group B), presence of residual disease, an R2 resection, advanced T stage, and lymph node involvement were associated with decreased overall survival on univariable Cox regression. Only group A (hazard ratio, 2.63; 95% CI, 1.25-5.54) and group C (hazard ratio, 2.07; 95% CI, 1.17-3.66) time intervals (vs group B), R2 resection (hazard ratio, 2.69; 95% CI, 1.27-5.69), and advanced Tstage (hazard ratio, 1.85; 95% CI, 1.11-3.08) persisted on multivariable Cox regression analysis. CONCLUSIONS AND RELEVANCE The optimal time interval for re-resection for incidentally discovered gallbladder cancer appears to be between 4 and 8 weeks after the initial cholecystectomy.