Real-world analysis of metastatic prostate cancer demonstrates increased frequency of PSA-imaging discordance with visceral metastases and upfront ARAT/docetaxel therapy

BackgroundThe objective of this study was to evaluate the background and treatment course of patients with metastatic prostate cancer (PC), with a particular focus on radiographic progression in the absence of prostate-specific antigen (PSA) progression. MethodsThe study population consisted of 229 patients with metastatic hormone-sensitive PC (HSPC), who received prostate biopsy and androgen deprivation therapy at Kobe University Hospital between January 2008 and June 2022. Clinical characteristics were retrospectively evaluated using medical records. PSA progression-free status was defined as <= 1.05 times greater than that from 3 months before. Multivariate analyses were performed using the Cox proportional hazards regression model to identify parameters associated with time to progression on imaging without PSA elevation. ResultsA total of 227 patients with metastatic HSPC without neuroendocrine PC were identified. The median follow-up period was 38.0 months, with a median overall survival of 94.9 months. Six patients exhibited disease progression on imaging without PSA elevation during HSPC treatment, three during first-line castration-resistant PC (CRPC) treatment, and two during late-line CRPC treatment. The rate of disease progression without PSA elevation at 3 years after treatment initiation was 7.4%. Multivariate analysis revealed that organ metastases and upfront treatment with docetaxel or androgen receptor axis-targeted therapy were independent prognostic factors for imaging progression without PSA elevation. ConclusionsDisease progression on imaging without PSA elevation occurred not only during HSPC treatment and first-line CRPC treatment, but also during late-line CRPC treatment. Patients with visceral metastases or those treated with upfront androgen receptor axis-targeted or docetaxel may be more prone to such progression.