Prognostic Significance of the Lymph Node Ratio in Surgical Patients With Distal Cholangiocarcinoma.

BACKGROUND: The aim of this study was to compare the prognostic impact of the lymph node ratio (LNR) versus positive lymph node count (PLNC) in patients who had undergone resection for distal cholangiocarcinoma.

METHODS: We identified 448 patients with resected distal cholangiocarcinoma from the Surveillance, Epidemiology, and End Results database. The X-Tile program was used to calculate the cutoff values for the LNR and PLNC that discriminate survival. The overall survival and cancer-specific survival rates were calculated. Relationships between clinicopathological factors and patient survival were assessed using univariate and multivariate analyses.

RESULTS: The optimal cutoff values for the LNR and PLNC were 0.45 and 3, respectively. Univariate analysis revealed that tumor size, the American Joint Committee on Cancer stage, T stage, the LNR and PLNC were significantly associated with prognosis (P < 0.05). Multivariate analysis demonstrated that the LNR, T stage, and tumor size were independent prognostic factors for cancer-specific and overall survival, whereas PLNC was not. In the subgroup of patients with positive lymph nodes, patients with an LNR of greater than 0.45 had significantly worse cancer-specific survival (hazard ratio, 2.418; 95% confidence interval, 1.588 to 3.682; P < 0.001) and overall survival (hazard ratio, 2.149; 95% CI, 1.421 to 3.249; P < 0.001) than those with an LNR of 0.45 or less.

CONCLUSIONS: The LNR was a better predictor of long-term prognosis than PLNC in patients with distal cholangiocarcinoma.