Clinical significance of resection and adjuvant chemotherapy for pancreatic ductal adenocarcinoma with occult para-aortic lymph node metastasis.

Background: This study aimed to determine the clinical significance of resection of pancreatic ductal adenocarcinoma diagnosed with occult para-aortic lymph node metastasis using intraoperative para-aortic lymph node sampling.

Methods: Between January 2005 and May 2021, a total of 606 patients who underwent surgery for pancreatic ductal adenocarcinoma with intraoperative para-aortic lymph node sampling were retrospectively investigated and divided into the resected para-aortic lymph node-negative (n = 543), resected para-aortic lymph node-positive (n = 44), and unresected para-aortic lymph node-positive (n = 19) groups. Overall survival, clinicopathologic characteristics, and prognostic factors were analyzed.

Results: The overall survival in the resected para-aortic lymph node-positive group was significantly worse than that in the resected para-aortic lymph node-negative group (3-year overall survival, 29.8% vs 48.4%, P < .001) and significantly better than that in the unresected para-aortic lymph node-positive group (3-year overall survival, 29.8% vs 0.0%, P = .008). In the resected para-aortic lymph node-positive group, adjuvant chemotherapy was an independent prognostic factor (hazard ratio = 2.689, P = .033). The overall survival of patients in the resected para-aortic lymph node-positive group who received adjuvant chemotherapy was comparable to that of patients in the resected para-aortic lymph node-negative group who had 4 or more regional lymph node metastases and received adjuvant chemotherapy (3-year overall survival, 33.9% vs 34.1%, P = .343). A logistic regression analysis showed that neoadjuvant therapy, age <65 years, creatinine clearance >60 mL/min, pancreatic body or tail tumor, and serum albumin level >3.5 g/dL were significant predictive factors for induction of adjuvant chemotherapy in 587 resected patients.

Conclusions: Resection may be acceptable for patients with para-aortic lymph node-positive pancreatic ductal adenocarcinoma who are likely to tolerate adjuvant chemotherapy.