Effect of immune checkpoint molecular mechanisms on the prognosis of prostate cancer patients treated with postoperative radiotherapy

2023 Fiscal Year Final Research Report

• Project/Area Number: 20K08055
• Research Category: Grant-in-Aid for Scientific Research (C)
• Allocation Type: Multi-year Fund
• Section: 一般
• Review Section: Basic Section 52040:Radiological sciences-related
• Research Institution: Jichi Medical University
• Principal Investigator: Shirai Katsuyuki 自治医科大学, 医学部, 教授 (10400748)
• Co-Investigator(Kenkyū-buntansha): 赤羽 佳子 自治医科大学, 医学部, 助教 (00835960)
• Project Period (FY): 2020-04-01 – 2024-03-31
• Keywords: 放射線治療 / 前立腺癌 / 免疫染色 / 免疫チェックポイント分子機構 / X線治療 / Cribriform pattern

Outline of Final Research Achievements

Radiotherapy is effective for postoperative recurrence of prostate cancer, however the outcomes are still not satisfactory. We evaluated the influence of the molecular mechanisms of immune checkpoints on prognosis, using specimens from patients who underwent postoperative radiotherapy. There were 50 patients who underwent postoperative radiation therapy. Immunostaining was performed using surgical specimens to examine the expression of various proteins, including immune checkpoint molecular mechanisms (PD-L1, PD-1), however none of these were predictive of recurrence. A cribriform pattern, one of the histopathological feature, was found to be a predictive marker of the recurrence. We are currently submitting a paper on our findings regarding the prognostic impact of cribriform patterns.

Free Research Field

放射線腫瘍学

Academic Significance and Societal Importance of the Research Achievements

前立腺癌における根治的治療は手術療法とならび放射線治療の役割は大きい。術後PSA再発に対する放射線治療の成績は、IMRTなどの治療の高精度化に伴い、成績の改善が認められる。しかし、照射後にさらに再発をきたす症例も多く、治療成績予測因子についての探索は重要となる。腫瘍検体を用いて、病理学的な検討や、免疫染色を用いた予後予測に関連する蛋白の発現について検討した結果、病理検体におけるCribriform patternの発現が予後に影響していることを明らかにした。これらの新しい知見は、将来的な治療成績の改善の一助となり、ひいては社会貢献に結びつくものと考える。