Oncologic outcome and the optimal time of sequential extended cholecystectomy in incidentally found T2 gallbladder cancer.

Introduction Sequential extended cholecystectomy (SEC) is currently recommended for gallbladder cancer (GBC) stage T2 and higher incidentally found after simple cholecystectomy (SC), but the value, timing and extent of re-resection has not been fully studied. This study evaluated long-term oncologic outcomes according to the type of surgery and time interval from initial cholecystectomy to SEC. Methods Patients diagnosed with T2 GBC who underwent extended cholecystectomy (EC), SEC or SC between 2002 and 2017 were retrospectively reviewed. Results In 226 patients diagnosed with T2 GBC, 173, 44, and 53 patients underwent EC, SEC, and SC, respectively. Age, ASA performance score was higher in the SC group than EC and SEC groups combined. Five-year overall survival (OS) was 73.2%, 78.7%, and 50.1%, and disease-free survival (DFS) was 66.3%, 65.2%, and 46.8% for EC, SEC, and SC patients, respectively. OS and DFS were higher in EC than SC (p = 0.007 and p = 0.001), higher in SEC than SC (p = 0.001 and p = 0.065), but similar between EC and SEC (p = 0.909 and p = 0.722). SEC patients who underwent SEC ≤ 30 days after initial cholecystectomy had longer DFS than the > 30 days group (114 months vs. 71 months; p = 0.023). Recurrence pattern (local or distant) of SC vs. EC and SEC combined showed significant difference, but not between EC and SEC. Seventeen of 18 SC recur patients had distant metastasis at the time of recurrence. Conclusions SEC is recommended for incidental T2 GBC because SEC provides better survival outcomes than SC alone. A time interval of ≤ 30 days between initial cholecystectomy and SEC is recommended.