Abstract：
BACKGROUND: There is little evidence regarding the safety and efficacy of the combination of abemaciclib plus radiotherapy (RT). The majority of studies investigated the combination of RT with palbociclib or ribociclib reporting that hematological toxicity is common. Given the unique toxicity profile of abemaciclib with greater gastrointestinal toxicity compared to hematological toxicity, we wanted to evaluate the toxicity of the combination with RT in metastatic breast cancer (BC) patients.
METHODS: Patients with histologically proven metastatic or locally advanced BC treated with RT and concurrent abemaciclib were selected. Toxicity was assessed according to the NCI-CTCAE V4.0.
RESULTS: Thirty-two metastatic sites were treated in 19 patients and analyzed. All patients received abemaciclib during the RT course. A total of 68% of patients received a full dose of abemaciclib during RT. Also, 71.9% of patients received a palliative intent (median dose = 30 Gy, range = 8-30 Gy), and 26.3% were treated for 9 oligo-metastatic or oligo-progressive sites of disease with stereotactic body RT (median dose = 30 Gy, range 21-30 Gy, given in 3-5 fractions). Overall, the rate of G3 toxicity was 15.7%. The rate of G3 hematological toxicity was 10.6% (2/19 patients, one G3 neutropenia and one G3 anemia). No patient presented diarrhea, including those treated for RT sites close to the bowel. One patient developed G3 skin toxicity. Pain significantly improved after RT (mean value NRS pre-RT = 3.9, SD = 3.07; mean value NRS after RT = 0.9, SD = 0.46; p < 0.0001).
CONCLUSIONS: Abemaciclib and concomitant RT seem well tolerated showing acceptable toxicity.
METHODS: Patients with histologically proven metastatic or locally advanced BC treated with RT and concurrent abemaciclib were selected. Toxicity was assessed according to the NCI-CTCAE V4.0.
RESULTS: Thirty-two metastatic sites were treated in 19 patients and analyzed. All patients received abemaciclib during the RT course. A total of 68% of patients received a full dose of abemaciclib during RT. Also, 71.9% of patients received a palliative intent (median dose = 30 Gy, range = 8-30 Gy), and 26.3% were treated for 9 oligo-metastatic or oligo-progressive sites of disease with stereotactic body RT (median dose = 30 Gy, range 21-30 Gy, given in 3-5 fractions). Overall, the rate of G3 toxicity was 15.7%. The rate of G3 hematological toxicity was 10.6% (2/19 patients, one G3 neutropenia and one G3 anemia). No patient presented diarrhea, including those treated for RT sites close to the bowel. One patient developed G3 skin toxicity. Pain significantly improved after RT (mean value NRS pre-RT = 3.9, SD = 3.07; mean value NRS after RT = 0.9, SD = 0.46; p < 0.0001).
CONCLUSIONS: Abemaciclib and concomitant RT seem well tolerated showing acceptable toxicity.
摘要：
背景：关于abemaciclib联合放疗（RT）的安全性和有效性的证据很少。大多数研究调查了RT与Palbociclib或Ribociclib的组合，报告血液学毒性是常见的。鉴于Abemaciclib的独特毒性特征与血液毒性相比具有更大的胃肠道毒性，我们希望评估联合放疗对转移性乳腺癌(BC)患者的毒性.
方法：选择经组织学证实的转移性或局部晚期BC患者，同时接受RT和Abemaciclib治疗。根据NCI-CTCAEV4.0评估毒性。
结果：对19例患者的32个转移部位进行了治疗和分析。所有患者在RT过程中接受了Abemaciclib。68%的患者在RT期间接受了全剂量的Abemaciclib。71.9%的患者接受了姑息治疗（中位剂量=30Gy，范围=8-30Gy)，26.3％的患者接受了立体定向放射治疗（SBRT）的9个寡转移或寡进展部位的治疗（中位剂量=30Gy，范围21-30Gy在3-5个部分中给出。总体而言，G3毒性率为15.7%。G3血液学毒性率为10.6%(2/19例,1例G3中性粒细胞减少症和1例G3贫血)。没有病人出现腹泻,包括那些在靠近肠道的RT部位接受治疗的患者。一名患者出现G3皮肤毒性。RT后疼痛显着改善（RT前NRS平均值=3.9，SD=3.07；RT后NRS平均值=0.9，SD=0.46；p=<0.0001）结论：Abemaciclib和伴随RT似乎耐受性良好，毒性可接受。
方法：选择经组织学证实的转移性或局部晚期BC患者，同时接受RT和Abemaciclib治疗。根据NCI-CTCAEV4.0评估毒性。
结果：对19例患者的32个转移部位进行了治疗和分析。所有患者在RT过程中接受了Abemaciclib。68%的患者在RT期间接受了全剂量的Abemaciclib。71.9%的患者接受了姑息治疗（中位剂量=30Gy，范围=8-30Gy)，26.3％的患者接受了立体定向放射治疗（SBRT）的9个寡转移或寡进展部位的治疗（中位剂量=30Gy，范围21-30Gy在3-5个部分中给出。总体而言，G3毒性率为15.7%。G3血液学毒性率为10.6%(2/19例,1例G3中性粒细胞减少症和1例G3贫血)。没有病人出现腹泻,包括那些在靠近肠道的RT部位接受治疗的患者。一名患者出现G3皮肤毒性。RT后疼痛显着改善（RT前NRS平均值=3.9，SD=3.07；RT后NRS平均值=0.9，SD=0.46；p=<0.0001）结论：Abemaciclib和伴随RT似乎耐受性良好，毒性可接受。
