Prognostic nutritional index is an independent prognostic factor for treatment response, survival and drug choice in metastatic castration-resistant prostate cancer treated with abiraterone acetate or enzalutamide

Purpose: We designed this study to identify the prognostic value of baseline prognostic nutritional index (PNI) in metastatic castration-resistant prostate cancer (mCRPC) patients treated with abiraterone acetate or enzalutamide.

Methods: 101 mCRPC patients were included. PNI was calculated using formula 10 x serum albumin value (gr/dL) + 0.005 × total lymphocyte count (per mm3). ROC analysis was used for determining prognostic PNI value.

Results: The statistically significant cut-off value for PNI was 46.62. Initial PSA response and PSA kinetics (early PSA response and 30 %-50%-90% PSA response at any time) were much better in PNI > 46.62 group than the PNI ≤ 46.62 group (p < 0.01). In multivariate analysis, baseline PNI level >46.62 was an independent predictor of PSA-PFS (HR: 0.42, p < 0.01), radiologic PFS (HR: 0.53, p < 0.01), and OS (HR: 0.42, p < 0.01). In the PNI ≤ 46.62 group, median OS was 7.4 months (95% CI: 4.1-10.7) for the abiraterone acetate subgroup vs. 17.6 months (95% CI: 10.1-25.1) for enzalutamide subgroups (p < 0.01).

Conclusion: PNI is a useful, independent prognostic marker for mCRPC patients treated with either abiraterone acetate or enzalutamide. Using pre-treatment PNI may help clinicians in the prediction of survival and decision making based on abiraterone acetate or enzalutamide.