Kawaoka Tomokazu, Ando Yuwa, Yamauchi Masami, Suehiro Yosuke, Yamaoka Kenji, Kosaka Yumi, Fuji Yasutomo, Uchikawa Shinsuke, Morio Kei, Fujino Hatsue, Nakahara Takashi, Ono Atsushi, Murakami Eisuke, Takahashi Shoichi, Tsuge Masataka, Hiramatsu Akira, Imamura Michio, Chayama Kazuaki, Aikata Hiroshi
Department of Gastroenterology and Metabolism, Graduate School of Biomedical and Health Sciences, Hiroshima University, Hiroshima, Japan.
Department of Clinical Oncology, Hiroshima Prefectural Hospital, Hiroshima, Japan.
Hepatol Res. 2020 Jul;50(7):885-888. doi: 10.1111/hepr.13496. Epub 2020 Mar 6.
Pembrolizumab has been quickly approved in many countries for the treatment of patients with unresectable or metastatic, microsatellite instability-high (MSI-H) solid tumors, which have progressed following previous treatment and who have no satisfactory alternative treatment options. We aimed to determine the incidence of MSI-H tumors in Japanese patients with advanced hepatocellular carcinoma (HCC).
We investigated the incidence of MSI-H tumors in 82 consecutive Japanese patients with unresectable HCC that had progressed after standard of care treatment. Using a companion diagnostic sequencing kit (polymerase chain reaction analysis of five microsatellite markers: BAT25, BAT26, NR21, NR24 and MONO27), we analyzed 49 biopsy specimens and 33 resection specimens. Responses to pembrolizumab were assessed with the modified Response Evaluation Criteria in Solid Tumors.
MSI-H tumors were found in only two patients (2.4%), in whom all five markers showed slight shortening. One patient had a complete response to pembrolizumab for over 10 months, and the other was a non-responder.
MSI-H tumor status was found in only two of 82 (2.4%) Japanese patients with advanced HCC, one of whom had a complete response to pembrolizumab. Thus, MSI status should be assessed in patients with HCC who progress after standard of care treatment.
帕博利珠单抗已在许多国家迅速获批，用于治疗既往治疗后进展且无满意替代治疗方案的不可切除或转移性微卫星高度不稳定（MSI-H）实体瘤患者。我们旨在确定日本晚期肝细胞癌（HCC）患者中MSI-H肿瘤的发生率。
我们调查了82例连续的日本不可切除HCC患者，这些患者在接受标准治疗后病情进展，分析MSI-H肿瘤的发生率。使用配套诊断测序试剂盒（对五个微卫星标记物进行聚合酶链反应分析：BAT25、BAT26、NR21、NR24和MONO27），我们分析了49份活检标本和33份切除标本。采用改良的实体瘤疗效评价标准评估对帕博利珠单抗的反应。
仅在两名患者（2.4%）中发现MSI-H肿瘤，这两名患者的所有五个标记物均显示轻微缩短。一名患者对帕博利珠单抗完全缓解超过10个月，另一名患者无反应。
在82例日本晚期HCC患者中，仅2例（2.4%）发现MSI-H肿瘤状态，其中1例对帕博利珠单抗完全缓解。因此，对于在标准治疗后病情进展的HCC患者，应评估其MSI状态。
