Purpose: CDK4/6 inhibitors require meticulous monitoring due to their potential to cause hematological toxicities and hepatotoxicity. This study evaluates the safety of combining CDK4/6 inhibitors with palliative radiotherapy in patients with metastatic hormone receptor-positive and HER2-negative breast cancer. Patients and Methods: This study included 188 patients treated with CDK4/6 inhibitors between January 2021 and June 2024. Data on patient demographics, tumor characteristics, and treatment interventions were extracted from medical records. The primary focus was on the incidence of grade ≥ 3 hematologic toxicities and hepatotoxicity, assessed according to CTCAE 5.0 criteria, in those receiving concurrent palliative radiotherapy. Results: With a median follow-up of 18.5 months, the 18-month PFS and OS rates were 67% and 85%, respectively. The median age was 57.5 years, and 79% of patients were post-menopausal. Bone and liver metastases were present in 66% and 23% of patients, respectively. Concurrent palliative radiotherapy was administered in 25% of the cohort. The incidence of grade ≥ 3 hematologic toxicity was comparable between those who received radiotherapy and those who did not. Ribociclib use was associated with lower rates of grade 3 hematologic toxicity (OR: 0.37), neutropenia (OR: 0.41), dose interruptions (OR: 0.30), and dose reductions (OR: 0.37). Pre-menopausal status was linked to fewer dose reductions (OR: 0.17). Rates of treatment interruption, dose reduction, and withdrawal were 55%, 24%, and 2%, respectively. Conclusions: The concurrent use of CDK4/6 inhibitors and palliative radiotherapy does not increase the incidence of hematological adverse events in patients with metastatic breast cancer.
目的：CDK4/6抑制剂因其可能导致血液学毒性和肝毒性而需要严密监测。本研究旨在评估CDK4/6抑制剂联合姑息性放疗在转移性激素受体阳性、HER2阴性乳腺癌患者中的安全性。患者与方法：本研究纳入了2021年1月至2024年6月期间接受CDK4/6抑制剂治疗的188例患者。从病历中提取了患者人口统计学、肿瘤特征和治疗干预措施的数据。主要关注点是根据CTCAE 5.0标准评估接受同期姑息性放疗的患者中≥3级血液学毒性和肝毒性的发生率。结果：中位随访时间为18.5个月，18个月无进展生存率和总生存率分别为67%和85%。患者中位年龄为57.5岁，79%为绝经后状态。分别有66%和23%的患者存在骨转移和肝转移。队列中25%的患者接受了同期姑息性放疗。接受放疗与未接受放疗的患者之间，≥3级血液学毒性的发生率相当。使用瑞博西利与较低的3级血液学毒性（OR：0.37）、中性粒细胞减少症（OR：0.41）、剂量中断（OR：0.30）和剂量减少（OR：0.37）发生率相关。绝经前状态与较少的剂量减少相关（OR：0.17）。治疗中断、剂量减少和停药的发生率分别为55%、24%和2%。结论：在转移性乳腺癌患者中，CDK4/6抑制剂与姑息性放疗同期使用并未增加血液学不良事件的发生率。
Palliative Radiotherapy in Metastatic Breast Cancer Patients on CDK4/6 Inhibitors: Safety Analysis
肿瘤(癌症)患者之家