Testosterone levels at diagnosis: A key predictor of overall survival among patients with prostate cancer

Background and Objective The exact relationship between testosterone levels at diagnosis and prostate cancer (PCa) prognosis remains inadequately explored. The objective was to determine whether serum testosterone levels at the time of PCa diagnosis are associated with overall survival. Patients and Methods The study cohort involved 2544 PCa patients, divided into three groups; normal (>10.4 nmol/L), grey zone (8.0-10.4 nmol/L) and low (2.0-8.0 nmol/L) serum testosterone groups. Survival outcomes were analysed using Kaplan-Meier curves and Cox regression models. Results The analysis revealed an increased risk of death among patients with low testosterone levels compared to those with normal levels in uni- (HR = 1.67, 95% CI: 1.37-2.05, p < 0.001) and multivariable-adjusted (HR = 1.58, 95% CI: 1.24-1.98, p < 0.001) analysis. Sensitivity analysis on patients with normal glucose metabolism revealed similar results (HR = 1.93, CI: 1.48-2.51, p < 0.001), as well as after stratified with age below 70 years (HR = 1.55, 95% CI: 1.02-2.36, p < 0.001) and over 70 years (HR = 1.83, 95% CI: 1.46-2.28, p < 0.001.) There was no difference in survival between the grey zone compared to other testosterone groups. The retrospective design limits our ability to infer causality. Conclusion Low testosterone at the time of PCa diagnosis is an independent predictor of overall survival. Findings highlight the potential of testosterone for prognostic evaluation in PCa.