Improved overall survival is still observed in patients receiving delayed adjuvant chemotherapy after pancreaticoduodenectomy for pancreatic adenocarcinoma.

Background: Adjuvant chemotherapy (AC) is associated with improved survival following resection of pancreatic adenocarcinoma but is frequently delayed or deferred due to perioperative complications or patient deconditioning. The aim of this study was to assess impact of delayed AC on overall survival after pancreaticoduodenectomy for pancreatic head adenocarcinoma.

Methods: Patients with stage I-III pancreatic head adenocarcinoma in the 2006-2015 National Cancer Database were grouped by timing of AC (<6-weeks, 6-12-weeks, and 12-24-weeks). Overall survival was compared using Cox proportional hazard models adjusting for patient, tumor, and hospital factors. Subgroup analyses were conducted to assess the impact of comorbidities, readmission or extended hospital stay, and receipt of single- versus multi-agent chemotherapy.

Results: Of 13438 patients, 4552 (33.9%) received no AC, 2112 (15.7%) received AC <6-weeks following resection, 5580 (41.5%) within 6-12 weeks, and 1194 (8.9%) within 12-24 weeks. AC was associated with improved overall survival (adjusted hazard ratio [HR] <6-weeks: 0.765, 6-12-weeks: 0.744, and 12-24-weeks: 0.736 (p < 0.001)). This survival advantage persisted for patients with comorbidities, those with postoperative complications, and in those receiving single- or multi-agent regimens.

Conclusions: For patients with stage I-III pancreatic adenocarcinoma, receipt of AC is associated with improved overall survival, even if delayed up to 24-weeks.