Prognostic value and clinical outcome analysis of PADI2 expression on tumor and tumor-infiltrating immune cells in resected pancreatic cancer patients

Purpose Pancreatic ductal adenocarcinoma (PDAC) is one of the most aggressive and lethal cancers worldwide, primarily due to the absence of effective early detection methods and targeted therapies. PADI2, an enzyme mediating citrullination, has been implicated in cancer progression and immune modulation, yet its clinical role in PDAC remains unclear. Methods In this study, PADI2 expression was assessed by immunohistochemistry in tumor cells (TCs) and tumor-infiltrating immune cells (TILs) from 31 PDAC patients. Results While PADI2 in TCs showed no prognostic relevance, high TIL-PADI2 expression was significantly associated with shorter progression-free (p = 0.006), disease-specific (p = 0.004), and overall survival (p = 0.016). Multivariate Cox regression confirmed TIL-PADI2 as an independent prognostic factor. Conclusions These findings suggest that PADI2 in immune cells—not cancer cells—may reflect a tumor-permissive microenvironment and serve as a novel biomarker for risk stratification and therapeutic targeting in PDAC.