Inhibition Effect of Pancreatic Exocrine Insufficiency on Immune Checkpoint Inhibitor Treatment in Pancreatic Cancer: A Retrospective Study.

Abstract

Chemotherapy combined with immune checkpoint inhibitors (ChIM) is used to treat advanced pancreatic ductal adenocarcinoma (PDAC). However, the efficacy of ChIM is similar to that of chemotherapy alone. To assess potential factors affecting the effectiveness of ChIM, we analyzed the clinical data of 359 patients with PDAC who visited the hospital during June 2017 to December 2022. Surgical resection, diabetes, and ChIM were risk factors for pancreatic exocrine insufficiency (PEI). The adjusted odds ratio of ChIM was 2.63 (95% confidence interval (CI) 1.492-4.626) (P = 0.001). The incidence of PEI in the ChIM group (76.9%) was significantly higher than that of the chemotherapy group (60.2%) (P = 0.004). Survival analysis showed that ChIM did not improve the survival rate of patients with PDAC (hazard ratio (HR) 0.92, 0.707-1.197) (P = 0.534) in comparison with that of the chemotherapy group. However, in patients without PEI, those receiving ChIM showed a higher 1-year overall survival (OS) rate of 70.8% (two-sided, P = 0.045) and a median OS of 22.0 months (95% CI 11.5-32.5). Moreover, pancreatic enzyme replacement therapy significantly improved the OS of patients with PDAC (HR = 0.73, 95% CI = 0.561-0.956) (P = 0.022). Immune checkpoint inhibitors (ICIs) increased the incidence of PEI in patients with PDAC. The OS was not different between patients receiving chemotherapy and ChIM due to irregular PERT treatment. The finding show that pancreatic enzyme replacement therapy may improve the response rate of patients with PDAC to ICIs.