The prognostic immune nutritional index is a predictive biomarker in metastatic castration-resistant prostate cancer treated with abiraterone or enzalutamide

Objective: To investigate the predictive efficacy of the geriatric nutritional risk index (GNRI) and novel prognostic immune nutritional index (PINI) in patients with metastatic castration–resistant prostate cancer (mCRPC) receiving abiraterone or enzalutamide.

Methods: We reviewed patients with mCRPC who received abiraterone or enzalutamide at the Suleyman Demirel University Hospital between 2015 and 2019. The GNRI was calculated using serum albumin and body mass index, with a GNRI <92.0 indicating poor nutritional status, and PINI was calculated using albumin and monocyte counts. The risk of survival was assessed using multivariate cox-regression analysis.

Results: No statistically significant difference was found between the mean age of men and women in the study. Eighty-three patients with mCRPC were included. In the low PINI group, it was 77.1% (PINI≤3.42). The median overall survival (OS) was 17 months in the low PINI group and 25 months in the high PINI group (p=0.001). The median OS was 21 and 25 months in the abiraterone and enzalutamide groups respectively; however the difference was not statistically significant (p=0.88). In a multivariate model, only low PINI was an independent risk factor for OS (Hazard Ratio [HR]=5.89, 95% Confidence Interval [CI]=2.07 to 16.7, p< 0.001).

Conclusion: In mCRPC patients treated with abiraterone or enzalutamide, a low PINI≤ 3.42 is associated with a shorter OS. The GNRI assessment for OS in patients with mCRPC treated with abiraterone or enzalutamide was not appropriate for our patients because only one patient had a low nutritional status (GNRI<92). There was no statistically significant difference in OS between the patients treated with abiraterone and those treated with enzalutamide.