Division of Radiation Oncology, Department of Oncology, University of Alberta & Cross Cancer Institute, Edmonton, Canada.
University of Alberta, Edmonton, Canada.
Radiother Oncol. 2021 Jan;154:93-100. doi: 10.1016/j.radonc.2020.09.017. Epub 2020 Sep 14.
The relative benefit of adjuvant radiotherapy (RT) alone in older women with low-risk early breast cancer (EBC) remains unclear. It is hypothesized that adjuvant RT-alone can improve outcomes of older patients with low-risk EBC, similar to endocrine therapy (ET) alone or combination of RT + ET.
In this population based study, we identified all women aged ≥70 with T1-2, N0, ER+ve, Her-2/neu-ve EBC treated with breast conserving surgery (BCS), followed by adjuvant treatments (RT-alone, ET-alone, or RT + ET combination) from 2005 to 2015. Primary outcome measures were recurrence-free survival (RFS), overall survival (OS), and breast cancer specific survival (BCSS). Treatment details were collected and Charlson Comorbidity Index (CCI) was calculated.
A total of 1166 patients were identified. Median follow-up was 76.5 months. Adjuvant treatments: BCS only 130 (11%), RT 378 (32.5%), ET 161 (14%), and RT + ET 497 (42.5%). Less than 60% of women completed 5-years of ET. Compared to BCS alone, RT resulted in significant improvement in RFS (HR = 0.174; p < 0.001), similar to ET (HR = 0.414; p = 0.007) and RT + ET (HR = 0.236; p < 0.001). Determinants of OS were age, tumor grade, comorbidities, and adjuvant therapy. Increased comorbidity scores (0 vs. 1; 0 vs. ≥2) were associated with reduced OS (HR = 1.40; p = 0.013 and HR = 1.98; p < 0.001), without impact on RFS or BCSS.
Adjuvant RT-alone is a reasonable alternative to ET or RT + ET for older women with biologically favorable EBC. No difference in RFS or BCSS was noted between RT, ET, and RT + ET. Comorbidity was independently associated with reduced overall survival.
辅助放疗（RT）对低危早期乳腺癌（EBC）老年女性的相对益处尚不清楚。假设辅助 RT 单药治疗可以改善低危 EBC 老年患者的结局，类似于内分泌治疗（ET）单药治疗或 RT+ET 联合治疗。
在这项基于人群的研究中，我们从 2005 年至 2015 年期间，确定了所有接受保乳手术（BCS）治疗的 T1-2、N0、ER 阳性、Her-2/neu 阴性 EBC 且年龄≥70 岁的女性，她们接受了辅助治疗（RT 单药治疗、ET 单药治疗或 RT+ET 联合治疗）。主要观察终点是无复发生存率（RFS）、总生存率（OS）和乳腺癌特异性生存率（BCSS）。收集治疗细节并计算 Charlson 合并症指数（CCI）。
共纳入 1166 例患者。中位随访时间为 76.5 个月。辅助治疗：BCS 单药治疗 130 例（11%），RT 378 例（32.5%），ET 161 例（14%），RT+ET 497 例（42.5%）。不到 60%的女性完成了 5 年的 ET 治疗。与 BCS 单药治疗相比，RT 显著改善了 RFS（HR=0.174；p<0.001），与 ET（HR=0.414；p=0.007）和 RT+ET（HR=0.236；p<0.001）相似。OS 的决定因素是年龄、肿瘤分级、合并症和辅助治疗。合并症评分增加（0 分与 1 分；0 分与≥2 分）与 OS 降低相关（HR=1.40；p=0.013 和 HR=1.98；p<0.001），但对 RFS 或 BCSS 无影响。
对于生物学特征有利的低危 EBC 老年女性，辅助 RT 单药治疗是 ET 或 RT+ET 的合理替代方案。RT、ET 和 RT+ET 之间在 RFS 或 BCSS 方面无差异。合并症与总生存降低独立相关。
