Post hoc subgroup analysis of neoadjuvant gemcitabine plus S1 vs gemcitabine plus nab paclitaxel in elderly resectable/borderline resectable pancreatic adenocarcinoma

This study aimed to evaluate the safety and feasibility of two neoadjuvant chemotherapy (NAC) regimens, gemcitabine plus nab-paclitaxel (GA) and gemcitabine plus S-1 (GS), for elderly patients (aged 75 years and older) with resectable and borderline resectable pancreatic ductal adenocarcinoma (R/BR-PDAC). A post hoc analysis was conducted using data from a randomized controlled trial on NAC for R/BR-PDAC (CSGO-HBP-015). Patients were divided into two groups: those aged 75 years and older (7/46 in GS and 16/48 in GA) and those under 75 years. Short-term outcomes, including resection rates, adverse events (AEs), postoperative complications, and the administration of adjuvant chemotherapy, were compared between age groups for both regimens. The incidence of AEs in patients aged 75 years and older tended to be higher than those of younger patients in both chemotherapy arms, but the differences were not statistically significant. However, the resection rates, postoperative complication rates, and the administration of adjuvant chemotherapy were not affected by age. Both regimens showed comparable safety profiles in elderly and younger cohorts. The GA and GS regimens can be safely administered as NAC for R/BR-PDAC in elderly patients without adversely affecting postoperative outcomes. These findings suggest that both regimens are feasible NAC options even for patients 75 years and older, supporting the need for further randomized controlled trials to validate these outcomes in the elderly population.Trial registration. UMIN Clinical Trials Registry UMIN000021484. This trial began in April 2016, and first registration (First Posted date) is 01/04/2016.