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Open Access 10-04-2025 | Prostate Cancer | Case report - Molecularly targeted therapy

Two Japanese patients with metastatic castration-resistant prostate cancer with somatic biallelic BRCA2 loss and RB1 splice site variant or loss who responded to Poly-ADP-ribose polymerase inhibitor: A case report

Authors: Shiori Miyachi, Takeshi Sasaki, Momoko Kato, Katsunori Uchida, Shunsuke Owa, Taketomo Nishikawa, Shinichiro Higashi, Hiroto Yuasa, Kouhei Nishikawa, Yoshinaga Okugawa, Masatoshi Watanabe, Takahiro Inoue

Published in: International Cancer Conference Journal

Abstract

We treated two patients with metastatic castration-resistant prostate cancer (mCRPC) who achieved a response duration of more than 12 months with Poly-ADP-ribose polymerase inhibitor (PARPi). Case 1 was a patient in his 60s with lung metastases, and case 2 was in his 70s and presented liver metastases. Genetic tests (FoundationOne^® CDx) were performed. Both patients had somatic biallelic BRCA2 loss, together with RB1 splice site variant (NM_000321.3:c.2489 + 1G > C) or RB1 loss. After PARPi administration, their metastatic sites had shrunk enough to keep partial response. These cases suggested that patients with mCRPC with biallelic BRCA2 loss and the RB1 splice site variant or loss may have remarkable response to PARPi.

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Title: Two Japanese patients with metastatic castration-resistant prostate cancer with somatic biallelic BRCA2 loss and RB1 splice site variant or loss who responded to Poly-ADP-ribose polymerase inhibitor: A case report
Authors: Shiori Miyachi
Takeshi Sasaki
Momoko Kato
Katsunori Uchida
Shunsuke Owa
Taketomo Nishikawa
Shinichiro Higashi
Hiroto Yuasa
Kouhei Nishikawa
Yoshinaga Okugawa
Masatoshi Watanabe
Takahiro Inoue
Publication date: 10-04-2025
Publisher: Springer Nature Singapore
Keywords: Prostate Cancer
Prostate Cancer
Metastasis
Published in: International Cancer Conference Journal
Electronic ISSN: 2192-3183
DOI: https://doi.org/10.1007/s13691-025-00761-2

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Two Japanese patients with metastatic castration-resistant prostate cancer with somatic biallelic BRCA2 loss and RB1 splice site variant or loss who responded to Poly-ADP-ribose polymerase inhibitor: A case report

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