Unveiling the mechanisms of immune evasion in pancreatic cancer: may it be a systemic inflammation responsible for dismal survival?

PURPOSE

Pancreatic cancer (PC) is one of the most aggressive malignancies with no effective treatment if diagnosed in advanced stage. Systemic inflammation is a recognized characteristic of cancer progression, and we believe that the understanding of the influence of inflammatory parameters may contribute to therapeutic improvement in PC. Here, we validated the Eosinophil/Lymphocyte Ratio (ELR) together with the Neutrophil/Lymphocyte Ratio (NLR) and their components, as prognostic factors in PC patients treated with chemoradiation.

METHODS

A total of 66 consecutive patients (p) diagnosed with PC stage I-III and treated with External Beam Radiotherapy + chemotherapy ± surgery (28p) in our institution from 2007 to 2018 were retrospectively evaluated. The impact of pre-treatment ELR ≥ 0.04, NLR ≥ 1.9, neutrophilia (≥ 7.0 × 10/l), eosinophilia (≥ 0.5 × 10/l) and lymphopenia (< 1.0 × 10/l) on Overall Survival (OS) and Time-to-Progression (TTP) was evaluated both in the entire cohort and separately according to surgical status.

RESULTS

Higher ELR was associated with longer OS and TTP, both in surgically treated and not operable patients. On univariate analysis, elevated ELR was associated with better OS (HR = 0.3, 95% IC 0.13-0.65, p = 0.003), contrarily to neutrophilia (HR = 2.7, 95% IC 1.2-6.5, p = 0.026) and age > 50 years (HR = 2.6, 95% IC 1.03-6.6, p = 0.044), while NLR, lymphopenia and Ca-19.9 were not significant. On multivariate regression, independent prognosticators for OS were: ELR, age and neutrophilia; while for TTP: ELR, neutrophilia, eosinophilia and lymphopenia.

CONCLUSIONS

The host's immune response influences survival outcomes of PC patients and may be of interest for future research.