Prognostic impact of lung metastasis in patients treated with androgen receptor signaling inhibitors for castration-sensitive prostate cancer: data from the ULTRA-Japan Consortium

Background Androgen receptor signaling inhibitors (ARSIs) have become the standard treatment for metastatic castration-sensitive prostate cancer (mCSPC). While visceral metastases, including lung metastases (LMs), are considered poor prognostic factors, their impact on clinical outcomes in mCSPC remains unclear. This study aimed to evaluate the prognostic significance of LM in mCSPC patients treated with ARSI-based doublet therapy. Methods This retrospective study analyzed a multi-institutional cohort of 453 mCSPC patients treated with ARSIa-based doublet therapy. Results The median overall survival (OS) and time to castration resistance (TTCR) were 80 and 41 months, respectively, with a median follow-up of 20 months. The total cohort included 117 patients (25.8%) with LM and 336 patients (74.2%) without LM. LATITUDE high-risk and CHAARTED high-volume criteria classified 380 patients (83.9%) and 356 patients (78.6%), respectively. Although not statistically significant, OS and TTCR showed a trend toward better outcomes in the LM group compared to the non-LM group in LATITUDE high-risk (n = 380: P =.097 for OS and P =.104 for TTCR) and CHAARTED high-volume (n = 356: P =.064 for OS and P =.086 for TTCR). In the propensity score matching cohort (n = 218 and n = 206 for LATITUDE and CHAARTED criteria, respectively), OS and TTCR remained comparable between the LM and non-LM groups. Conclusions LM does not appear to be related to OS or TTCR in mCSPC patients treated with ARSI-based doublet therapy, indicating that its prognostic value may need to be reevaluated.