Locations of metastases in and oncological outcomes of patients with metastatic castration-sensitive prostate cancer: Real-world data from a multicenter study.

BACKGROUND

Androgen receptor-signaling inhibitors (ARSIs) have significantly changed the preferred treatments for metastatic castration-sensitive prostate cancer (mCSPC). Despite such advances, the prognostic significance of metastases at specific sites remains unclear. This study evaluated how metastatic site affected the oncological outcomes of mCSPC patients.

METHODS

This retrospective multicenter study included 716 mCSPC patients receiving androgen- deprivation therapy (ADT) alone, combined androgen blockade (CAB) therapy, or both ARSI and ADT (ARSI doublet) from February 2018 to June 2023. All patients were categorized based on their metastatic sites. The primary endpoint was the time to castration-resistant prostate cancer (CRPC) development; the secondary endpoints were progression-free survival 2 (PFS2), cancer-specific survival (CSS), and overall survival (OS). Kaplan-Meier curves and multivariate Cox's regression models were used to analyze the survival outcomes. We stratified mCSPC patients with bone metastases by the volumes of such metastases and lung metastasis status, and explored the clinical significance of lung metastasis.

RESULTS

Patients with lung-only metastases experienced better outcomes than those with other visceral metastases. On multivariate analysis, the bone metastasis volume, but not lung metastasis status, significantly affected CRPC-free survival status. No significant difference in any of CRPC, PFS2, CSS, or OS status was apparent among patients with bone metastases with or without lung metastases. In terms of interaction, lung metastasis did not significantly affect the prognoses of patients with either low- or high-volume bone metastases.

CONCLUSION

In the present era of ARSI doublet therapy, lung-only metastases in mCSPC patients were associated with favorable outcomes. The negative prognostic effects of lung metastases were much lower than was the bone metastasis volume, indicating that treatments targeting low-volume disease may be adequate even when lung metastases are apparent.