P30. Adjuvant Chemotherapy in Pancreatic Ductal Adenocarcinoma Patients After Pathologic Complete Response to Neoadjuvant Treatment: Necessary or Overtreatment? An Insight from NCDB

Pancreatectomy is the main treatment for patients with resectable pancreatic ductal adenocarcinoma (PDAC). Neoadjuvant treatment (NAT) has emerged as an important strategy to improve outcomes in patients with borderline resectable and locally advanced PDAC. The pathologic response to NAT serves as an important surrogate marker of NAT efficacy. The aim of this study was to evaluate the potential benefit of adjuvant chemotherapy (AC) in PDAC patients who achieved a pathologic complete response (PCR) after receiving NAT.


Methods:

Utilizing the National Cancer Database, we included all patients with stage I–III PDAC diagnosed between 2010 and 2021 who achieved a PCR after receiving NAT and followed by a pancreatectomy. Patients who died within 30 days of surgery were excluded. PCR was defined as ypT0ypN0. Multivariable Cox hazard regression analysis was performed to evaluate factors associated with overall survival (OS). Kaplan–Meier survival analysis was used to demonstrate OS across different groups.


Results:

Among 16,858 individuals who met the inclusion criteria, 536 (3.2%) patients achieved a PCR. Patients with a PCR had a higher median OS compared to those who did not achieve a PCR (105 vs 25 months, p < 0.001) (Figure 1). Among patients with a PCR, 106 (19.8%) received AC. There was no statistically significant difference in baseline characteristics (age, sex, Charlson comorbidity index, cT, cN, and tumor location) between patients who did or did not receive AC. Among patients that achieved a PCR, the adjusted multivariable analysis revealed no significant difference in survival between patients who received AC and those who did not (adjusted hazard ratio [aHR]: 0.86; 95% CI: 0.57-1.31; P = 0.49). However, among patients who did not achieve a PCR, receiving AC was associated with higher OS compared to patients who did not receive AC (aHR: 0.78, 95% CI: 0.73-0.83, P < 0.001).


Conclusions:

Although the rate of a PCR remains low among PDAC patients who received NAT, receiving AC after achieving a PCR was not associated with a survival difference. This study also confirmed findings from previous studies that OS was significantly higher among patients that achieved a PCR. Nevertheless, AC was associated with higher survival in patients that did not have a PCR. These findings should be considered when discussing role of adjuvant treatment for patients with PDAC that have a PCR after NAT.