Pancreatic cancer metastatic to a limited number of lymph nodes has no impact on outcome

Background: The purpose of this study was to determine the association of the extent of metastatic lymph node involvement with survival in pancreatic cancer. Methods: This is a retrospective review of a prospectively maintained database of patients who underwent resection for pancreatic adenocarcinoma, 1999-2011. Results: 165 patients were identified and divided into 3 groups based on the number of positive lymph nodes - 0 (group A), 1-2 (B), >3 (C). Each group had 55 patients. Those in group C were more likely to have a higher T stage, poorly differentiated grade, lymphovascular invasion (LVI), higher mean intra-operative blood loss, positive margins, tumor location involving the uncinate process, and a higher likelihood of undergoing a pancreaticoduodenectomy. Median overall survival (OS) for group A, B and C was 25.5 months (mo), 21 mo and 12.3 mo, respectively (p < 0.001). No survival difference was noted for survival between groups A and B (p = 0.86). The ratio of involved lymph nodes <0.2 was predictive of improved survival (p < 0.001). Conclusions: Resected pancreatic cancer patients with only 1-2 positive lymph nodes or less than 20% involvement have a similar prognosis to patients without nodal disease. Current staging should consider stratification based on the extent of nodal involvement.