Prognostic significance of inflammatory indices in predicting treatment response in patients with metastatic pancreatic cancer receiving FOLFIRINOX therapy

Aim: This study aims to evaluate the effect of the systemic inflammation response index (SIRI), the pan immune inflammation value (PIV), and the combined risk score (CPS) calculated from these parameters, measured before treatment, on treatment response and prognosis in patients with metastatic pancreatic cancer receiving FOLFIRINOX (folinic acid, fluorouracil, irinotecan, oxaliplatin). Materials and Methods: A total of 52 patients who received the FOLFIRINOX treatment regimen for metastatic pancreatic cancer between January 2016 and March 2025 at the Department of Internal Medicine, Division of Medical Oncology, Çukurova University Balcalı Training and Research Hospital, and the Department of Internal Medicine, Division of Medical Oncology, Mersin University Faculty of Medicine were included in the study. Pre treatment laboratory values of leukocytes, neutrophils, monocytes, lymphocytes, hemoglobin, and albumin were recorded for all patients, along with demographic and clinical data including age, sex, date of malignancy diagnosis, date of treatment initiation, progression status, survival status, date of death (if applicable), histopathological subtype and localization of the tumor, metastatic site(s) at diagnosis, number of treatment cycles received, and interim response evaluation, by reviewing the electronic medical records of the hospitals. The systemic inflammation response index (SIRI) was calculated using neutrophil, monocyte, and lymphocyte counts, while the pan immune inflammation value (PIV) was calculated using neutrophil, monocyte, platelet, and lymphocyte counts. In addition, a new combined risk score (CPS) was developed using these two indices. Subsequently, the association of these three indices with overall survival (OS) in this patient cohort was investigated. Results: The mean age of the 52 patients included in the study was 62.6 years (±8.3). Of these patients, 28 were male (53.8%) and 24 were female (46.2%). In the multivariate Cox regression analysis, male sex was observed to be associated with a 2.51 fold higher risk of mortality compared to female sex (p=0.037). A low SIRI score, compared with a high SIRI score, was significantly associated with longer median overall survival (30.9 months vs. 15.1 months, p=0.020, respectively). Similarly, a low PIV score, compared with a high PIV score, was significantly associated with longer median overall survival (24.3 months vs. 15.1 months, p=0.018, respectively). Moreover, patients classified as low CPS risk demonstrated longer median overall survival compared with those in the intermediate and high risk CPS groups (39.9 months vs. 16.3 months vs. 15.1 months, p=0.031, respectively). Furthermore, in both univariate and multivariate Cox regression analyses, intermediate and high risk CPS groups were found to be associated with a significantly higher risk of mortality compared with the low risk CPS group (p=0.011). XI Conclusion: Considering the limitations of our study, although larger prospective studies are needed on this subject, our data suggest that SIRI, PIV, and CPS indices may be effective markers in predicting prognosis in this patient group. Keywords: FOLFIRINOX, combined risk score, pan--immune inflammation value, pancreatic cancer, systemic inflammation response index.