Specific diagnostic value of systemic immune-inflammation indices combined with nutritional and tumor markers in the stage diagnosis of pancreatic cancer: a retrospective cohort study.

Objective: To investigate the specific diagnostic value of the systemic immune-inflammation index (SII) and systemic inflammation response index (SIRI) combined with the prognostic nutritional index (PNI) and tumor markers (CA19-9 and CEA) in the stage diagnosis of pancreatic cancer. Methods: This single-center retrospective cohort study consecutively enrolled 257 patients with pathologically confirmed pancreatic cancer. Patients with stage I-II disease were classified as the early-stage pancreatic cancer group, while those with stage III-IV disease were classified as the non-early group. Clinical and pathological characteristics, as well as pretreatment peripheral blood inflammatory, nutritional, and tumor marker data, were collected. SII, SIRI, and PNI were calculated. Differences in these parameters were compared across tumor stages and degrees of differentiation. Results: Compared with the early-stage group, patients with non-early-stage pancreatic cancer had significantly higher levels of SII, SIRI, CA19-9, and CEA, while PNI was significantly lower (all Conclusions: The combination of systemic immune-inflammation indices with nutritional parameters and tumor markers significantly enhances the specificity and accuracy of early-stage pancreatic cancer diagnosis. This multi-marker strategy provides an important complementary diagnostic approach, particularly in CA19-9-negative patients.