Optimal assessment of lymph node status in gallbladder cancer

Background: Lymph node (LN) metastasis is an important prognostic factor in gallbladder cancer (GBCA). LN status has been adopted as a critical element of staging systems. However, the influence of total lymph node count (TLNC) remains unclear. We determined the optimal minimum TLNC and compared the prognostic significance of LN status indices in GBCA. Methods: We retrospectively reviewed medical records of 128 patients with T2 or greater GBCA who underwent LN dissection. We analyzed overall survival (OS) and relevance of the number of metastatic LNs, ratio of metastatic LNs to retrieved LNs (LNR), and TLNC in predicting OS. Results: The median OS durations were 120, 35, and 18 months in T2, T3, and T4 GBCA. Five-year OS rates were 73%, 43%, and 0% in T2, T3, and T4 GBCA. LN status did not significantly impact OS in T2 or T4 GBCA. However, all LN indices were significantly correlated with OS in T3 GBCA. Furthermore, multivariate analysis revealed that a metastatic LN count of more than four and a TLNC of more than eight were independent prognostic factors of OS in T3 GBCA. Conclusions: TLNC and the number of positive LNs may be more important prognostic factors than LNR in T3 GBCA. Additionally, accurate staging may not be achieved in cases of T3 GBCA if the total number of retrieved LNs is less than eight. Thus, to ensure proper staging, we recommend that surgeons harvest more than eight LNs in patients with T3 GBCA. (C) 2015 Elsevier Ltd. All rights reserved.