Neoadjuvant therapy is associated with improved survival in resectable pancreatic adenocarcinoma

Abstract

Background: Neoadjuvant therapy has been used to improve survival in operable pancreatic cancer. The authors' objective was to compare long-term outcomes in patients receiving neoadjuvant versus adjuvant therapy for resectable pancreatic adenocarcinoma.

Methods: The California Cancer Surveillance Program for Los Angeles County retrospectively identified 458 patients with nonmetastatic pancreatic adenocarcinoma who underwent definitive pancreatic resection and received systemic chemotherapy between 1987 and 2006. The cohort was grouped by timing of systemic therapy-neoadjuvant or adjuvant. Clinicopathologic characteristics and overall survival were compared. Multivariate Cox regression analysis was used to determine the benefit of neoadjuvant therapy, independent of other significant factors.

Results: Of the 458 patients, 39 (8.5%) received neoadjuvant therapy, and 419 (91.5%) received adjuvant therapy. There was a significantly lower rate of lymph node positivity in the neoadjuvant group (45% vs 65%; P = .011) despite a higher rate of extrapancreatic tumor extension. On Kaplan-Meier analysis, the neoadjuvant group had significantly better overall survival compared with the adjuvant group (median survival, 34 vs 19 months; P = .003). Overall survival was also improved in the neoadjuvant therapy patients with extrapancreatic disease (median survival, 31 vs 19 months; P = .018). On multivariate Cox regression analysis, neoadjuvant therapy was an independent predictor of improved survival (hazard ratio, 0.57; 95% confidence interval, 0.37-0.89; P = .013).

Conclusions: This is the first population-based study to compare neoadjuvant versus adjuvant treatment strategies in resectable pancreatic cancer. Neoadjuvant therapy is associated with a lower rate of lymph node positivity and improved overall survival and should be considered an acceptable alternative to the surgery-first paradigm in operable pancreatic cancer.