Increasing negative lymph node count is independently associated with improved long-term survival in resectable perihilar cholangiocarcinomas.

To evaluate the prognostic value of numbers of negative lymph nodes (NLNs) for patients with perihilar cholangiocarcinomas.The surveillance, epidemiology, and end results database was used to screen for patients with perihilar cholangiocarcinomas. Kaplan-Meier and Cox regression analyses were used for statistical evaluations. Subsequently, propensity score matching (PSM) was performed to confirm the results.A total of 938 patients with perihilar cholangiocarcinomas met the inclusion criteria. The cut-off number for the grouping of patients with different numbers of NLNs was 17. Both the univariate and multivariate survival analyses demonstrated that there was a significant improvement in terms of cancer-specific survival for patients with >17 NLNs, compared with patients with ≤17 NLNs. Then, the above results were confirmed via a PSM procedure. Additionally, the independent prognostic value of NLNs was evaluated in subgroup univariate and multivariate analyses of patients with stage I or stage II tumors.The numbers of NLNs were evaluated and determined to be important independent prognostic factors for the cancer-specific survival of patients with perihilar cholangiocarcinomas.