Background: The aim of the present study was to determine the optimal number of lymph nodes (LN) examined to stage pN0 tumors after surgery for ampulla of Vater carcinoma (AVC).
Methods: We reviewed retrospectively 127 patients with AVC who underwent pancreaticoduodenectomy (1990-2008). Univariate and multivariate analysis was performed.
Results: Fifty-nine patients (46.5 %) were pN0, whereas 68 patients (53.5 %) were pN1. The 5-year disease-specific survival (DSS) was worse for pN1 patients than for pN0 patients (46 vs. 77 %; P < 0.0001). In the pN0 cohort, the optimal cut-off number of LN analyzed was found to be 12. The 5-year DSS for patients with ≤ 12 LN was 50 %, compared with 89 % in those with >12 LN (P = 0.001). By multivariate analysis, a LN count >12 was the only independent predictor associated with improved survival (HR 0.16, P = 0.003) among pN0 patients. Among pN1 patients, a LN count >12 was associated with a significantly better 5-year DSS (59 vs. 22 %; P = 0.027). Patients with a lymph node ratio (LNR) >0.20 had a 5-year DSS of 24 %, compared with 58 % in those with 0 < LNR ≤ 0.20 (P = 0.038).
Conclusions: Removal of more than 12 LN for examination is associated with improved survival rate after surgery for AVC in both pN0 and pN1 patients.