Neoadjuvant Chemotherapy for Intraductal Papillary Mucinous Neoplasm-derived Pancreatic Cancer

Intraductal papillary mucinous neoplasm (IPMN)-derived pancreatic cancer is typically managed like pancreatic intraepithelial neoplasia (PanIN)-derived pancreatic cancer. However, in IPMN-derived pancreatic cancer, the role of chemotherapy remains controversial, particularly in the neoadjuvant setting (NAT). To evaluate the role of neoadjuvant chemotherapy in IPMN-derived pancreatic cancer. Patients with IPMN-derived pancreatic cancer treated with either upfront surgery (US) or NAT were identified from eight international centers (2000-2023). Clinicopathologic data were compared. Date of first treatment was used for Kaplan-Meier and log-rank tests to compare overall (OS) and recurrence free survival (RFS). Multivariable Cox-regression was performed in patients that underwent NAT. In 1,019 patients, 76 (7%) underwent NAT. Patients who received NAT had higher baseline CA19-9 levels (P<0.001). Of these 76 patients, 27 (36%), 20 (26%), and 29 (38%) had resectable, borderline resectable, or locally advanced pancreatic cancer at diagnosis, respectively. Advanced resectability stage was significantly more common in the NAT patients as compared to those who underwent US (P<0.001). OS for US patients was 38.0 months (95%CI: 33.7.1-44.3), which was not statistically different than those that received NAT [27.5 mo (95%CI: 23.1-46.7), P=0.121]. This was also valid for patients with resectable disease [US: 38.1 mo vs. NAT: 35.6 mo, P=0.920)]. Complete or marked pathological treatment response (P=0.046) and serological CA19-9 normalization after NAT (P=0.017) were associated with improved survival. On Cox-regression for OS, N2 disease [HR: 4.15 (95%CI: 1.71-10.10)], elevated CA19-9 [HR: 2.02 (95%CI:1.06-3.85)] and R1 margin [HR: 2.36 (95%CI:1.20-4.61)] was independently associated with OS after NAT, while resectability status was not. After NAT and resection, advanced resectability stage was not associated with worse OS indicating the value of this approach for borderline resectable and locally advanced IPMN-derived pancreatic cancer. The benefit of NAT in resectable disease is unclear and may require an individualized approach. Biological treatment effect can be assessed with CA19-9 and confirmed by pathologic response.