The role of lymph nodes in predicting the prognosis of ampullary carcinoma after curative resection

BACKGROUND Lymph node involvement is one of the well-demonstrated prognostic factors in ampullary carcinoma. The aim of this study is to clarify the role of lymph nodes in predicting the survival outcome of ampullary carcinoma. METHODS A cohort of consecutive curative pancreaticoduodenectomies for ampullary carcinoma from 1999 to 2014 was retrospectively analyzed. The effect of node-associated variables, including lymph node status, positive lymph node number, total harvested lymph node (THLN) number, and lymph node ratio (LNR) was examined using univariate and multivariate analyses for survival outcome prediction. RESULTS In 194 evaluable patients, univariate analysis demonstrated that stage, cell differentiation, perineural invasion, and nodal status were significant conventional prognostic factors. Concerning the node-associated variables, positive nodal status, positive lymph node number≥2, THLN number<14, and LNR≥0.15 were significantly associated with poorer survival outcomes, with a 5-year survival rate of 20.3, 38.9, 25.4, and 18%, respectively. By multivariate analysis, nodal status and THLN number were two independent predictors of survival. The most favorable 5-year survival rate was 84.4% in patients with negative nodal involvement and THLN number≥14, compared with the poorest 5-year survival rate of 16.1% in those with positive nodal status and THLN number<14. CONCLUSIONS Tumor biology reflected by lymph node status is the most important independent prognostic factor; nevertheless, surgical radicality based on THLN number also plays a significant role in the survival outcome for patients with ampullary carcinoma after curative pancreaticoduodenectomy.