Patterns of recurrence in genuine and induced oligometastatic castration‐resistant prostate cancer treated with progressive site‐directed therapy

• Published in: International journal of urology 2023-02, Vol.30 (2), p.204-210
• Main Authors: Yoshida, Soichiro, Takahara, Taro, Arita, Yuki, Toda, Kazuma, Kimura, Koichiro, Fujiwara, Motohiro, Tanaka, Hajime, Yokoyama, Minato, Matsuoka, Yoh, Yoshimura, Ryoichi, Fujii, Yasuhisa
• Format: Article
• Language: English
• Subjects: Castration; castration‐resistant; Diffusion Magnetic Resonance Imaging; Humans; Male; Metastases; Metastasis; oligometastasis; Progression-Free Survival; Prostate cancer; Prostate-Specific Antigen; prostatic neoplasms; Prostatic Neoplasms, Castration-Resistant - diagnostic imaging; Prostatic Neoplasms, Castration-Resistant - pathology; Prostatic Neoplasms, Castration-Resistant - therapy; radiotherapy; recurrence; Retrospective Studies
• ISSN: 0919-8172; 1442-2042
• DOI: 10.1111/iju.15090

Objectives To describe oncological outcomes after progressive site‐directed therapy (PSDT) in genuine and induced oligometasatic (OM)‐castration‐resistant prostate cancer (CRPC). Methods Thirty‐seven patients with OM‐CRPC treated with PSDT were retrospectively analyzed, and oncological outcomes and recurrence patterns on whole‐body diffusion‐weighted MRI (WB‐DWI) were evaluated. Results Twenty‐two (59%) were classified as genuine OM‐CRPC and 15 (41%) as induced OM‐CRPC. A 50% decline in PSA after PSDT was observed in 21 (95%) genuine OM‐CRPCs and 7 (47%) induced OM‐CRPCs (p = 0.0005). At a median observation period of 7.3 months, median PSA progression‐free survival were 10.9 months in the genuine OM‐CRPCs and 4.8 months in the induced OM‐CRPCs (p = 0.015). Among the patients who developed PSA progression after PSDT, 11 of 15 in the genuine OM‐CRPCs (73%) and 11 of 14 in the induced OM‐CRPCs (79%) underwent WB‐DWI at PSA progression. The median numbers of newly detected metastases were 2 (range: 1–5) in the genuine OM‐CRPCs and 4 (range: 1–40) in the induced OM‐CRPCs (p = 0.049). Only one new metastasis appeared in 5 patients from the genuine OM‐CRPCs (46%) and 1 from the induced OM‐CRPCs (9.1%, p = 0.048). In 7 of 9 patients from the genuine OM‐CRPCs (78%) and 7 of 8 patients from the induced OM‐CRPCs (88%) who had bone metastases alone, the newly detected metastasis limited to the bone. Conclusions Genuine OM‐CRPC had better oncological outcomes after PSDT than induced OM‐CRPC, and the number of lesions detected at recurrence was limited. Induced OM‐CRPC might be a disseminated condition with micrometastases at OM diagnosis.