Background: The treatment strategy for metastatic castration-sensitive prostate cancer (mCSPC) has changed significantly in recent years. Based on various guidelines, an upfront androgen receptor signaling inhibitor (ARSI) is the first choice, but in patients of Asian descent, including Japanese patients, there are a certain number of cases in which androgen deprivation therapy (ADT) and CAB are more effective. If patients can be identified who show a marked response to ADT within 12 weeks after the initiation of ADT, which is the inclusion criterion for ARSI clinical trials targeting mCSPC, it would be valuable from an economic standpoint. Methods: A total of 218 patients with pure prostate adenocarcinoma and treated with ADT at the Kanazawa University Hospital between January 2000 and December 2020 were included in this study. As a risk classification for mCSPC, in addition to the LATITUDE and CHAARTED criteria, we used the castration-sensitive prostate cancer classification proposed by Kanazawa University (Canazawa), developed by the Department of Urology of Kanazawa University. The Canazawa classification was based on three factors: Gleason pattern 5, bone scan index (BSI) ≥ 1.5, and lactate dehydrogenase (LDH) ≥ 300 IU/L. It defined patients with one factor or less as low-risk and patients with two or three factors as high-risk. The overall survival (OS) and time to castration resistance (TTCR) were estimated retrospectively using the Kaplan–Meier method, and factors associated with TTCR were identified using univariate and multivariate analyses. Results: The median follow-up period was 40.4 months, the median OS period was 85.2 months, and the median TTCR period was 16.4 months. The Canazawa risk classification provided the clearest distinction between the OS and TTCR in mCSPC patients. Multivariate analysis revealed a decrease in PSA levels of <95% at 12 weeks after ADT initiation and was a predictor of short TTCR in low-risk, low-volume patients across all risk classifications. Conclusion: The Canazawa classification differentiated the prognosis of mCSPC patients more clearly. A PSA reduction rate of <95% at 12 w after starting ADT in low-risk, low-volume patients of all risk classifications was significantly shorter than the TTCR. We propose a new treatment strategy, in which patients with low-risk mCSPC are treated with ADT and switched to ARSIs based on the rate of PSA reduction at 12 w.
背景：近年来，转移性去势敏感性前列腺癌（mCSPC）的治疗策略发生了显著变化。根据各类指南，前期使用雄激素受体信号抑制剂（ARSI）是首选方案，但在包括日本患者在内的亚洲裔患者中，存在一定数量的病例显示雄激素剥夺疗法（ADT）和联合雄激素阻断疗法（CAB）更为有效。若能识别出在ADT启动后12周内对ADT反应显著的患者——这亦是针对mCSPC的ARSI临床试验的纳入标准——从经济学角度将具有重要价值。 方法：本研究纳入了2000年1月至2020年12月期间在金泽大学医院接受ADT治疗的218例纯前列腺腺癌患者。作为mCSPC的风险分层，除了LATITUDE和CHAARTED标准外，我们还采用了由金泽大学泌尿外科提出的金泽大学去势敏感性前列腺癌分类（Canazawa分类）。该分类基于三个因素：格里森模式5、骨扫描指数（BSI）≥ 1.5以及乳酸脱氢酶（LDH）≥ 300 IU/L。它将具有一个或以下因素的患者定义为低风险，具有两个或三个因素的患者定义为高风险。采用Kaplan-Meier法回顾性评估总生存期（OS）和至去势抵抗时间（TTCR），并通过单变量和多变量分析确定与TTCR相关的因素。 结果：中位随访期为40.4个月，中位OS为85.2个月，中位TTCR为16.4个月。Canazawa风险分类在mCSPC患者的OS和TTCR之间提供了最清晰的区分。多变量分析显示，在所有风险分类的低风险、低肿瘤负荷患者中，ADT启动后12周时PSA水平下降<95%是TTCR较短的预测因子。 结论：Canazawa分类能更清晰地区分mCSPC患者的预后。在所有风险分类的低风险、低肿瘤负荷患者中，ADT启动后12周时PSA下降率<95%的患者，其TTCR显著更短。我们提出一种新的治疗策略：对于低风险mCSPC患者，先采用ADT治疗，并根据12周时的PSA下降率决定是否转换为ARSI治疗。
Novel Treatment Strategies for Low-Risk Metastatic Castration-Sensitive Prostate Cancer
肿瘤(癌症)患者之家