Pancreatic cancer patients with lymph node involvement by direct tumor extension have similar survival to those with node-negative disease.

Background: Lymph node (LN) involvement is a well-known poor prognostic factor in patients with pancreatic ductal adenocarcinoma (PDAC). However, there have been conflicting results on the significance of the mechanism of LN involvement, "direct" tumor invasion versus "metastatic," disease on patient survival.
Methods: Clinicopathologic records from all patients who underwent resection for PDAC from 1990 to 2014 at a single-institution were reviewed.
Results: Of the 385 total patients, there was tumor invasion outside of the pancreas in 289 (75.1%) patients. Overall, 239 (62.1%) had node-positive disease: 220 (92.0%) by "metastatic" involvement, 14 (5.9%) by "direct" tumor extension, and five (2.1%) by a mix of "metastatic" and "direct". There were no significant differences in clinicopathologic factors associated with PDAC survival between "metastatic" and "direct" LN patients. The median overall survival for the whole cohort was 31.1 months. Compared to overall survival in patients with LN-negative disease (median 40.7 months), those with LNs involved by "metastatic" spread was significantly shorter (median 25.7 months, P < 0.001), yet "direct" LN extension was similar (median 48.1 months, P = 0.719).
Conclusions: The mechanism of LN involvement affects PDAC prognosis. Patients with LNs involved by direct extension have similar survival to those with node-negative disease.
(© 2015 Wiley Periodicals, Inc.)