A Novel Prognostic Model Based on Prognostic Nutritional Index and Systemic Immune-Inflammation Index for Cancer Patients Treated with Immune Checkpoint Inhibitors

The prognostic nutritional index (PNI) and systemic immune-inflammation index (SII) have both been reported as important indicators of prognosis in cancer patients. This study sought to construct and evaluate a combined PNI-SII score for predicting outcomes in patients undergoing immune checkpoint inhibitor (ICI) therapy.

A total of 350 cancer patients treated with ICI-based therapy were retrospectively enrolled, with overall survival (OS) and progression-free survival (PFS) defined as the primary endpoints. The PNI-SII scoring model was developed as follows: score 0 (low SII and high PNI), score 1 (high SII or low PNI), score 2 (high SII and low PNI).

In the entire cohort, patients with high PNI level tended to have a significantly longer OS and PFS than those with low PNI level (both p<0.001), while the opposite was for patients with high SII level as compared with those with low SII level (OS, p<0.001; PFS, p=0.004). Consistently, the PNI-SII model was found to effectively stratify both OS and PFS in the entire cohort (both p<0.001), which was then confirmed in the subgroups stratified by cancer type, age, and smoking history. In addition, the PNI-SII score was associated with short-term treatment response and therapy-related adverse events.

The PNI-SII model may serve as a convenient prognostic indicator for cancer patients receiving ICI therapy. Due to the limitations of the present study, further clinical investigations are necessary to validate its efficacy.