Muraoka Satoshi, Tosuji Hisanobu, Iwahashi Yuya, Kawabata Hiroki, Deguchi Ryusuke, Wakamiya Takahito, Yamashita Shimpei, Kohjimoto Yasuo, Hara Isao
Department of Urology Wakayama Medical University Wakayama City Japan.
IJU Case Rep. 2025 Jun 20;8(5):449-453. doi: 10.1002/iju5.70062. eCollection 2025 Sep.
The use of pembrolizumab in patients with microsatellite instability-high (MSI-high) and tumor mutation burden-high (TMB-high) prostate cancer in Japan is not widely reported. Here, we report the case of a patient with MSI-high and TMB-high prostate cancer who responded well to pembrolizumab after multiple systemic treatments.
A 68-year-old Japanese man was diagnosed with cT4N1M1a prostate cancer. He was treated with several androgen receptor signaling inhibitors and chemotherapy. After intense systemic treatment, disease progression was confirmed, and genomic testing detected MSI-high and TMB-high. However, treatment with pembrolizumab resulted in marked prostate-specific antigen reduction and significant shrinkage of metastases.
Genomic tests should be considered for high-grade tumors. MSI-high and TMB-high prostate cancer responded well to pembrolizumab in this case, but patients should be carefully monitored for the development of side effects after administration of pembrolizumab.
在日本，帕博利珠单抗用于微卫星高度不稳定（MSI-H）和肿瘤突变负荷高（TMB-H）的前列腺癌患者的情况报道较少。在此，我们报告一例MSI-H和TMB-H前列腺癌患者，在接受多次全身治疗后对帕博利珠单抗反应良好的病例。
一名68岁的日本男性被诊断为cT4N1M1a期前列腺癌。他接受了多种雄激素受体信号抑制剂和化疗。经过强化全身治疗后，确认疾病进展，基因检测发现MSI-H和TMB-H。然而，帕博利珠单抗治疗导致前列腺特异性抗原显著降低，转移灶明显缩小。
对于高级别肿瘤应考虑进行基因检测。在本病例中，MSI-H和TMB-H前列腺癌对帕博利珠单抗反应良好，但在给予帕博利珠单抗后应密切监测患者副作用的发生。
