Comparison of pre-treatment systemic inflammation indices (systemic immune-inflammation index, systemic inflammation response index, and inflammatory benchmark index) in predicting mortality risk in patients with pancreatic cancer

Introduction
The aim of this study was to assess the inflammatory status of patients with pancreatic cancer (PC) prior to the initiation of the first course of chemotherapy and to ascertain the most precise systemic inflammation index for predicting overall survival (OS).

Material and methods
A single-centre retrospective analysis involving 310 pa- tients with PC was conducted. Blood samples were collected from patients during chemotherapy qualification, either on the first day of chemotherapy or the day before the first chemotherapy dose. The following inflammatory indices were calculated: systemic immune-inflammation index, systemic inflammation response index, and inflammatory benchmark index (IBI). Statistical analyses were performed utilizing appropriate tests (e.g., the log-rank test).

Results
All parameters were significant predictors of mortality; however, their area under the curve indicated only a moderate ability to differentiate mortality risk. Among the indices analysed, IBI was the sole metric that predicted OS in adjuvant (p < 0.05) and palliative (p < 0.001) cohorts, alongside disease-free survival (p < 0.04) and progression-free survival (p < 0.009). In the multivariate analysis, only IBI was proven to be statistically associated with OS (p < 0.043). Furthermore, IBI well stratified the tumour stage.

Conclusions
All analysed indices related to inflammation and immune response may function as prognostic markers; however, additional studies are required to determine their precise cut-off value. In our investigation, IBI exhibited a distinctive protective effect, culminating in a 65% reduction in mortality, thereby underscoring the importance of C-reactive protein in patient stratification.