Comparable impact of lymph node metastases in T2 gallbladder cancer on postoperative prognosis irrespective of the extent of the metastases: A retrospective analysis.

Background: Lymph node metastases beyond the hepatoduodenal ligament are sometimes encountered in locally limited T2 gallbladder cancer (GBCA). However, the incidence and impact on prognosis remain unclear.

Methods: This was a retrospective multi-institutional study of patients who underwent surgical resection for GBCA from 2002 to 2022. The eighth edition of the Union for International Cancer Control staging was used for tumor-node-metastasis categorization. The lymph node location was classified as follows: (A) along the hepatoduodenal ligament and common hepatic artery; (B) posterior side of the pancreatic head; and (C) others. Metastasis to regions A, B, and C nodes was denoted as Na, Nb, and Nc, respectively.

Results: Data for 379 patients (pT1, 29; pT2, 162: pT3, 141; and pT4, 47) were evaluated; none with pT1 GBCA had node metastasis. For N1/2 GBCA, the proportion of patients with N2 disease increased with increasing T grade (p = .001), while the proportions of patients with Na, Nb, and Nc disease were comparable between pT2 (61%, 26%, and 13%), pT3 (63%, 26%, and 12%), and pT4 (50%, 38%, and 12%) disease (p = .681), respectively. Overall survival for pT2N1/2 disease (5 years, 43.8%) was comparable to that for pT3/4N0 disease (5 years, 37.2%; p = .192). Among patients with node-positive pT2 disease, overall survival was comparable for Na, Nb, and Nc disease, with 5-year survivals of 46%, 43%, and 31%, respectively (p = .346).

Conclusions: Region B or C node metastasis was not rare even in pT2 GBCA. Regarding survival outcomes, pT2 node-positive GBCA should be considered advanced disease irrespective of the extent of node metastasis.