The Role of Prognostic Nutritional Index in Prognosis Prediction in Cases Diagnosed with Stage-IV Colorectal Cancer

Objective: Systemic inflammation and nutrition are closely linked to cancer prognosis.The prognostic nutritional index (PNI) has shown prognostic value in various gastrointestinal cancers.This study evaluates the prognostic value of PNI in Stage-IV colorectal cancer at diagnosis. Material and Methods:We retrospectively analyzed 82 patients diagnosed with Stage-IV colorectal cancer via biopsy at Akdeniz University Faculty of Medicine, Oncology Clinic between 01/01/2014 and 30/08/2022.Receiver operating characteristic (ROC) analysis determined the PNI cut-off for overall survival (OS).Cox regression was used for prognostic factor analysis.Results: A total of 82 patients were included (69.5% male; mean age 59.6 years).The ROC-defined baseline PNI cut-off was 45.25.Median OS was 35.5 months in the high PNI group versus 18.0 months in the low PNI group [hazard ratio (HR)=0.29,95% confidence interval (CI): 0.18-0.48,p<0.001).Median progression-free survivals were 15.0 months for the treatment group versus 9.0 months for the control group (HR=0.35,95% CI: 0.21-0.58,p<0.001).Patients with high baseline PNI also had higher complete response rates (29% vs. 2.9%) and lower rates of haematological toxicity.Analysis of PNI change showed that patients with greater increases in PNI had longer OS (36.5 vs. 20.0months, HR=0.42, 95% CI: 0.26-0.68,p=0.001) and PFS (14.0 vs. 9.0 months, HR=0.49, 95% CI: 0.30-0.79,p=0.004). Conclusion:PNI, a simple calculation, may aid prognosis prediction in metastatic colorectal cancer.