Propensity score matched analysis of neoadjuvant therapy for resectable pancreatic cancer.

Abstract

381 Background: Neoadjuvant therapy (NT) for resectable pancreatic cancer continues to be debated. There is little data to demonstrate survival benefit over patients who were treated with up front surgery (UFS) vs NT. We sought to examine the impact of neoadjuvant chemotherapy (NCT), neoadjuvant chemoradiation (NCRT), and UFS on survival in pancreatic cancer patients. Methods: The NCDB was accessed to identify patients with pancreatic adenocarcinoma. Propensity score matching (PSM) was performed against age, tumor size, margin status, and institutional surgery volume. Patient characteristics (continuous and categorical variables) were compared using Mann-Whitney U, Kruskal Wallis and Pearson’s Chi-square test as appropriate. Survival analyses were performed using the Kaplan-Meier method. Multivariable cox proportional hazard models (MVA) were developed to identify predictors of survival. All statistical tests were two-sided and α < 0.05 was considered significant. Results: After PSM, 5,034 patients (UFS 2,517; NT 2,517: 1,143 NCT and 1,374 NCRT) were included in the analysis. There was no difference in age, tumor size, or grade among cohorts. The mean nodes positive were 1.6 ± 2.6 in NT and 2 ± 3.3 in UFS, p = 0.02. In the pre-matched cohort R0 resections were performed in 75.9% UFS, 82.9% NCRT, and 79.6% NCT, p < 0.001. The median and 5 year survival for NCT, NCRT and UFS was 28.6 months and 25.2%, 25.7 months and 22.2%, and 21.3 months and 21.7%, p < 0.001. Adjuvant therapy (chemotherapy (CT) or CRT) in the UFS did demonstrate a survival benefit 22.5 months vs 18.6 months, p < 0.001, however this did not benefit NCT or NCRT, p = 0.8 and p = 0.8 respectively. Additionally survival in the UFS with adjuvant therapy either CT or CRT was still decreased compared to either NCT or NCRT, p < 0.001 and p = 0.001 respectively. MVA demonstrated that age, T-stage, lymph nodes positive, R0 resection, grade, NCT and NCRT were predictors of survival. Conclusions: Neoadjuvant therapy improves survival in resectable pancreatic cancer patients. NCT and NCRT demonstrated survival benefit compared to UFS even with adjuvant therapy. Patients with resectable pancreatic cancer should be considered for neoadjuvant therapy.