Genuine- and induced-oligometastatic castration-resistant prostate cancer: clinical features and clinical outcomes after progressive site-directed therapy.

To evaluate the clinical characteristics of genuine- and induced-oligometastatic castration-resistant prostate cancer (OM-CRPC) and assess the therapeutic effect of progressive-site directed therapy (PSDT).

We performed a retrospective analysis of 45 patients with OM-CRPC. Whole-body diffusion-weighted MRI (WB-DWI) was used to diagnose oligo-progressive disease. Based on the clinical and radiological findings, the OM-CRPCs were classified as genuine or induced. PSDT was performed with the intent to ablate all the progressive sites detected on WB-DWI with radiotherapy. Systemic therapy remained unchanged during and after PSDT.

A total of 31 (69%) and 14 (31%) patients were diagnosed with genuine- and induced-OM-CRPC, respectively. The genuine-OM-CRPC group had significantly fewer patients treated with taxane-based chemotherapy and new hormonal drugs than the induced-OM-CRPC group. Of these, 26 OM-CRPC patients were treated with PSDT, and a 50% PSA decline was observed in 14 (93%) of 15 patients with genuine-OM-CRPC and 4 (36%) of 11 patients with induced-OM-CRPC (P = 0.033). Further, the duration of PSA-progression-free survival was significantly longer in the genuine-OM-CRPC group than in the induced-OM-CRPC group (8.7 vs. 5.8 months, P = 0.040).

PSDT can be a promising treatment option for genuine-OM-CRPC. The procedure might also be considered effective for induced-OM-CRPC, although there was less therapeutic benefit of PSDT in patients with induced-OM-CRPC than in patients with genuine-OM-CRPC.

International urology and nephrology. 2021 Jan 16 [Epub ahead of print]

Soichiro Yoshida, Taro Takahara, Yuki Arita, Kazuma Toda, Ichiro Yamada, Hajime Tanaka, Minato Yokoyama, Yoh Matsuoka, Ryoichi Yoshimura, Yasuhisa Fujii

Department of Urology, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan. ., Department of Biomedical Engineering, Tokai University School of Engineering, Kanagawa, 259-1292, Japan., Departments of Diagnostic Radiology, Keio University School of Medicine, Tokyo, 160-8582, Japan., Department of Radiation Therapeutics and Oncology, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan., Department of Diagnostic Radiology and Nuclear Medicine, Tokyo Medical and Dental University, Tokyo, 113-8510, Japan., Department of Urology, Tokyo Medical and Dental University Graduate School, 1-5-45 Yushima, Bunkyo-Ku, Tokyo, 113-8510, Japan.