Most cases of metastatic castration-sensitive prostate cancer (mCSPC) eventually progress to metastatic castration-resistant prostate cancer (mCRPC), which is defined as progression despite castrate levels of serum testosterone. In clinical practice, progression is often assessed based on PSA kinetics. However, data on the prognostic impact of radiographic progressive disease (rPD) at mCRPC diagnosis remain limited.

Of 219 mCSPC patients treated at our institution from 2000 to 2020, 108 with available imaging data at CRPC progression were included. A retrospective chart review was conducted to assess the clinical significance of rPD.

The median age of the patients was 70 years, and the median PSA level was 234.5 ng/mL. A Gleason score ≥9 was observed in 69 patients (63.9%), N1 disease in 72 patients (66.7%), and M1c disease in 12 patients (11.1%). The rPD (-) and rPD (+) groups consisted of 57 and 51 patients, respectively. No significant differences in treatments after CRPC were observed between the groups. Multivariate analysis identified rPD and an alkaline phosphatase (ALP, IFCC) level ≥120 IU/L as significant independent predictors of both overall survival (OS) and prostate cancer-specific survival (PCSS) after CRPC.

Patients with rPD (+) and ALP ≥120 IU/L at mCRPC diagnosis had significantly poorer prognosis. These findings highlight the importance of regular imaging follow-up, alongside PSA and blood test monitoring, during mCSPC treatment.