A RECENT study has provided valuable insights into the phenomenon of radiographic disappearance of metastases (RDM) in patients with metastatic hormone-sensitive prostate cancer (mHSPC). This retrospective analysis examined the occurrence and prognostic significance of RDM in individuals undergoing treatment at a single institution between 2000 and 2023. The study aimed to determine the impact of RDM on treatment outcomes, particularly in patients receiving androgen receptor pathway inhibitors (ARPIs).
A total of 446 patients with mHSPC were included in the analysis. They had received either androgen deprivation therapy (ADT) alone, combined androgen blockade (CAB), or ADT combined with ARPIs such as abiraterone, enzalutamide, or apalutamide. Imaging assessments with computed tomography and bone scintigraphy were conducted at least twice to evaluate the presence or absence of metastatic lesions. The study defined total RDM as the complete disappearance of all detected metastatic sites on imaging.
The findings revealed that total RDM occurred in 15% of patients over a median follow-up period of 2.8 years. The likelihood of achieving total RDM was significantly higher in those receiving ARPIs (20%) compared to those in the ADT/CAB group (11%). Patients who experienced total RDM demonstrated markedly improved survival outcomes. The median castration-resistant prostate cancer progression-free survival (CRPC-PFS) was 8.2 years for patients with total RDM, compared to just 1.9 years for those without it. Similarly, the median overall survival (OS) was 16.0 years in the RDM group, whereas those without RDM had a median OS of 5.5 years.
Further statistical analyses confirmed that total RDM and undetectable PSA levels (≤0.2 ng/ml) were independently significant prognostic factors for overall survival. Propensity score matching also indicated that patients in the ARPIs group with total RDM had significantly longer CRPC-PFS and OS compared to their counterparts in the ADT/CAB group. Multivariate analysis identified ARPIs use as a strong predictive factor for achieving total RDM.
These results underscore the importance of metastasis control through ARPIs in mHSPC treatment. Furthermore, the study suggests that RDM could serve as a valuable surrogate marker for assessing treatment efficacy in patients with mHSPC.
Reference
Hashimoto K et al. The impact of radiographic disappearance of metastases as a new surrogate marker for therapy in patients with metastatic hormone-sensitive prostate cancer. Poster P190. EAU25, March 21-24, 2025.
