Survival outcomes of neoadjuvant versus adjuvant chemotherapy in early-stage pancreatic adenocarcinoma: A subgroup analysis of the National Cancer Database.

e16777 Background: Early-stage disease is diagnosed in 10-20% of patients with pancreatic adenocarcinoma (PAC). The current standard of care is upfront surgery followed by adjuvant chemotherapy (AC). The administration of the latter may be limited due to postoperative complications. The aim of this study is to determine the subgroups of patients with early-stage PAC who derive maximum benefit of neoadjuvant chemotherapy (NAC). Methods: Using the National Cancer Database 2004-15, we identified 20,003 patients with clinical stage I or II PAC who had surgery and received chemotherapy in any sequence. The baseline characteristics were compared using Pearson's chi‐square test between patients who received NAC versus AC. A separate multivariate Cox-proportional Hazard regression analysis was done for each subgroup to identify patients with the maximum survival benefit from NAC. Hazard ratio (HR) < 1 connotes survival benefit in favor of NAC. Results: Of the study population, 24% of the patients received NAC. The patients in the NAC group had more PAC of head (80% vs 73%), stage II disease (72% vs 53%), CA19-9 levels 50 U/ml (66% vs 59%), multiagent chemotherapy (68% vs 27%) and were treated at an academic facility (66% vs 52%) compared to the AC group. The p-value was < 0.001 for all comparisons. The age and sex distribution were similar in both groups. On multivariate survival analysis in the overall population, NAC had improved survival compared to AC (HR 0.88 95%CI 0.82-0.93, p < 0.001). Subgroup multivariate survival analysis is shown in the table. Conclusions: In early stage PAC, there is a trend towards survival benefit of NAC compared to AC in most subgroups. The maximum benefit is seen in younger patients with Stage II disease, high CA19-9 levels and fewer comorbidities who receive multiagent chemotherapy. This finding may partly be explained by better tolerability of preoperative compared to postoperative chemotherapy. A randomized clinical trial is needed to establish the optimal chemotherapy timing in patients with early-stage PAC who are treated with curative intent. [Table: see text]