Optimal Time Between Completion of Preoperative Chemotherapy and Surgery for Locally Advanced Pancreatic Cancer

Multimodal treatment with preoperative chemotherapy is increasingly used for locally advanced pancreatic cancer (LAPC) to enable surgical resection. However, the optimal time between the last cycle of preoperative chemotherapy and surgery remains unclear. This study aimed to evaluate the association between timing of surgery after preoperative chemotherapy and overall survival of patients with LAPC.

Patients with LAPC who underwent pancreatic resection after preoperative chemotherapy between 2018 and 2023 were enrolled from a prospectively maintained database. The cohort was stratified by a predefined interval between the last cycle of chemotherapy and surgery (short interval: < 4 weeks vs long interval: ≥ 4 weeks).

After preoperative chemotherapy, 169 patients underwent surgery, including 56 (33.1%) patients in the short-interval group and 113 (66.9%) patients in the long-interval group. Baseline characteristics, surgical procedures, and postoperative morbidity were comparable between the two groups. Most patients received FOLFIRINOX (85.5 %) with a median of nine cycles. Patients with the long interval showed significantly improved overall survival from the time of LAPC diagnosis (20.7 vs 29.5 months; p = 0.019) as well as from surgery (16.1 vs 23.1 months; p = 0.024). In multivariable analysis, the interval of 4 weeks or longer was an independent predictor of improved survival. Further analysis suggested an optimal time window of 4-8 weeks between the last chemotherapy cycle and surgery.

An interval of at least 4 weeks between the last cycle of preoperative chemotherapy and surgery for LAPC was associated with significantly improved overall survival, with an optimal window of 4-8 weeks.