Efficacy of Neoadjuvant Therapy for Resectable Pancreatic Cancer Might be Limited to Biologically Borderline Resectable Cases.

[BACKGROUND] Neoadjuvant therapy (NAT) followed by surgery is becoming a standard treatment even for resectable pancreatic cancer (RPC). However, it is unclear whether NAT is necessary for all RPC cases.

[METHODS] A total of 296 patients diagnosed with RPC and under 80 years old were retrospectively analyzed, focusing on tumor markers (TMs). The cutoff value of TM was decided based on the classification by the International Association of Pancreatology.

[RESULTS] Among 80 cases who underwent NAT, 72 cases accomplished surgical resection. Upfront surgery (UpS) was planned in 216 cases, and surgical resection was accomplished in 199 cases. Resection rate showed no difference between the two groups ( P = 0.638). Although NAT group showed a favorable trend in overall survival (OS) compared with the UpS group, the difference was not significant ( P = 0.143). carbohydrate antigen 19-9 >500 U/mL and/or duke pancreatic monoclonal antigen type 2 >700 U/mL was defined as high TM. When comparing in TM-high group (n = 83), patients with NAT showed significantly better OS than those without NAT ( P = 0.024). In TM-low group (n = 213), the OS curves completely overlapped with no difference ( P = 0.902). A multivariate analysis demonstrated that undergoing NAT was the sole independent prognostic factor in the TM-high group (hazard ratio: 0.48, P = 0.044) while undergoing NAT was not a prognostic factor in the TM-low group.

[CONCLUSION] The efficacy of NAT for RPC might be limited to the subset of patients with high TM.