Early Initiation of novel hormonal therapy is associated with improved survival in synchronous bone-metastatic hormone-sensitive prostate cancer: a retrospective cohort study from China

Background: The incidence and prognosis of synchronous bone-metastatic hormone-sensitive prostate cancer (SBM-HSPC) in contemporary China remain unclear. This study aimed to determine its current prevalence, characterize patient profiles, and identify independent prognostic factors. Methods: We conducted a retrospective cohort study of patients with SBM-HSPC diagnosed at a major tertiary center in China (2017-2023). Demographic, clinicopathological, treatment, and outcome data were analyzed. Overall survival (OS) was evaluated using Kaplan-Meier and Cox regression. A landmark analysis (3- and 6-month) was employed to assess the association between early treatment initiation and OS, mitigating immortal time bias. Results: The incidence of SBM-HSPC was 6.09%. The cohort presented with high-risk features: 93.1% had Gleason score ≥8,and 83.7% had high-volume disease (HVD). The median OS was 43 months. Multivariate analysis identified HVD as an independent risk factor (HR = 2.37, P = 0.012) and age 60-74 years as protective (HR = 0.52, P = 0.040) compared to age <60. Landmark analysis demonstrated that initiation of novel hormonal agents (NHA) within 3 months was associated with a 45% reduction in mortality risk (HR = 0.55, P<0.001), an association sustained at 6 months. In contrast, early use of docetaxel or bone-targeting agents was not associated with improved OS. Conclusion: The incidence of SBM-HSPC in this Chinese cohort aligns with data from developed healthcare systems. HVD is a key prognostic determinant. Early initiation of NHA therapy is strongly associated with a significant survival benefit, underscoring the critical need for timely, intensive systemic treatment in this high-risk patient population.