Clinical Features and Prognostic Significance of Pulmonary Metastases in Metastatic Hormone-sensitive Prostate Cancer

Background/Aim: Among visceral metastases, while the extremely poor prognosis of liver metastases is widely recognized, clinical significance of lung metastases (LM) remains poorly understood. This study investigated the clinical profiles and prognostic impact of LM in metastatic hormone-sensitive prostate cancer (mHSPC).

Patients and Methods: We reviewed the clinical records of 1445 patients from multiple institutions who had mHSPC with bone and/or lung metastases between 1999 and 2025. Castration-resistant prostate cancer progression-free survival (CRPC-PFS) and overall survival (OS) were examined. Multivariate Cox proportional hazard modeling and Kaplan-Meier curves were employed to study prognostic significance.

Results: Patients were categorized into three groups, with bone-only metastases (1,173 cases), both bone and lung metastases (225 cases), or lung-only metastases (47 cases). Patients with lung-only metastases were associated with lower initial prostate-specific antigen level, Gleason score, and percentage of lymph node metastases. Kaplan-Meier analysis showed that patients with LM had better OS than those without, particularly in high-volume mHSPC [p=0.0002; hazard ratio (HR)=1.58]. We further identified 103 patients classified as high-volume disease due to the presence of LM. Notably, these patients demonstrated significantly longer OS than other high-volume disease cases (p=0.0009; HR=1.87) and showed comparable OS to low-volume disease patients (p=0.8872; HR=1.03). Irrespective of the volume of bone metastases, no significant difference was observed in the incidence of LM.

Conclusion: mHSPC patients with LM exhibited a distinct clinical profile and more favorable prognosis in high-volume disease population. Tumor volume classification based on the presence of LM may require reevaluation to better guide treatment selection for patients with mHSPC.