Prognostic value of retrieved lymph node counts in patients with node-negative perihilar cholangiocarcinomas.

ABSTRACT

BACKGROUND: This study aimed to find out the prognostic value and optimal cut-off value of retrieved lymph node (LN) counts in patients with node-negative perihilar cholangiocarcinomas. METHODS: The Surveillance, Epidemiology and End Results (SEER) database was used to screen out patients with perihilar cholangiocarcinoma. The cut-off number of retrieved LNs was determined by the X-tile programme. Kaplan-Meier methods with log-rank tests and Cox regression analysis were used for survival analysis. RESULTS: A total of 778 patients with perihilar cholangiocarcinoma (2004-2014) met the inclusion criteria for this research, and there were 403 patients without LN metastases (N0) among them. The cut-off numbers of retrieved LNs, which were determined using the X-tile programme, were 8 and 18. Both results of univariate and multivariate survival analyses in N0 patients showed that patients with ≥18 retrieved LNs had a significantly better survival rate than patients with 1-7 retrieved LNs and patients with 8-17 retrieved LNs. In the subgroup of patients with early-stage tumours, patients with at least 13 retrieved LNs had a significantly better overall and cancer-specific survival than patients with fewer retrieved LNs. CONCLUSIONS: The retrieved LN counts are an independent prognostic factor for patients with node-negative perihilar cholangiocarcinoma. Patients with at least 18 retrieved LNs had a better overall and cancer-specific survival than patients with fewer retrieved LNs. The minimum requirement for retrieving of LNs should reach 18 in perihilar cholangiocarcinoma.