The Prognostic Value of a Composite Score in Predicting Mortality Among Metastatic Castration-resistant Prostate Cancer Patients Treated with Enzalutamide

Objective: This study aimed to develop a composite prognostic score using prostate-specific antigen (PSA) elimination rate, lactate dehydrogenase (LDH), alkaline phosphatase (ALP), and albumin derived from routine blood biochemistry tests in patients with castration-resistant prostate cancer and to evaluate the prognostic value of this index for overall survival. Material and Methods:This multicenter retrospective cohort study included 173 patients receiving enzalutamide treatment.The performance of PSA elimination rate, albumin/ALP ratio, and LDH/ALP ratio in mortality classification was evaluated using receiver operating characteristic analysis.The composite prognostic score was created by summing indices with significant area under the curve values.An increase in the score was interpreted as an increased mortality risk.The role of the composite score in predicting mortality was investigated. Results:The mean age of the patients included in the study was 68.618.57years (range: 43-87).PSA elimination rate, LDH/ALP ratio, and albumin/ALP ratio were found to be lower in the mortality group.The 10-year survival rate was 16.3% for patients with a composite prognostic score of 3, 32.3% for those with a score of 2, 46.5% for those with a score of 1, and 70.4% for those with a score of 0. The mean overall survival was 64.6 months for score 3, 99.6 months for score 2, 134.4 months for score 1, and 205 months for score 0 (p<0.001).Mortality risk was 2.85-fold lower in patients with a score of 1 [hazard ratio (HR): 0.35, p=0.001] and 2.56-fold lower in those with a score of 0 (HR: 0.39, p=0.036).In the Fagan nomogram, the post-test probability for the combined prognostic score was calculated as 68.1%. Conclusion:Based on our findings, the developed composite prognostic score demonstrated significant potential for predicting mortality.The combined use of PSA elimination rate, LDH/ALP ratio, and albumin/ALP ratio improved mortality prediction accuracy.This composite prognostic score may assist clinicians in decision-making regarding treatment strategies.