PURPOSE Randomized controlled trials demonstrate that omission of radiation therapy (RT) in older women with early-stage cancer undergoing breast conserving surgery (BCS) is an "acceptable choice." Despite this, high RT rates have been reported. The objective was to evaluate the impact of patient- and system-level factors on RT rates in a contemporary cohort. METHODS Through the National Cancer Data Base, we identified women with clinical stage I estrogen receptor-positive breast cancer who underwent BCS (n = 84,214). Multivariable logistic regression identified patient, tumor, and system-level factors associated with RT. Joinpoint regression analysis calculated trends in RT use over time stratified by age and facility-type, reporting annual percent change (APC). RESULTS RT rates decreased from 2004 (77.2%) to 2015 (64.3%). The decline occurred earliest and was most pronounced in older women treated at academic facilities. At academic facilities, the APC was - 5.6 (95% CI - 8.6, - 2.4) after 2009 for women aged > 85 years, - 6.4 (95% CI - 9.0, - 3.8) after 2010 for women aged 80 -  < 85 years, - 3.7 (95% CI - 5.6, - 1.9) after 2009 for women aged 75 -  < 80, and - 2.4 (95% CI, - 3.1, - 1.6) after 2009 for women aged 70 -  < 75. In contrast, at community facilities rates of RT declined later (2011, 2012, and 2013 for age groups 70-74, 75-79, and 80-84 years). CONCLUSIONS RT rates for older women with early-stage breast cancer are declining with patient-level variation based on factors related to life expectancy and locoregional recurrence. Facility-level variation suggests opportunities to improve care delivery by focusing on barriers to de-implementation of routine use of RT.

中文翻译：

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在70岁以上患有早期乳腺癌的女性中持续使用放射线是否能反映出以患者为中心的定制护理？

目的随机对照试验表明，在接受早期乳腺癌保乳手术（BCS）的老年妇女中，省略放射治疗（RT）是“可接受的选择”。尽管如此，已经报道了高RT率。目的是评估当代队列研究中患者和系统水平因素对放疗率的影响。方法通过美国国家癌症数据库，我们确定患有BCS的临床I期雌激素受体阳性乳腺癌妇女（n = 84,214）。多变量logistic回归确定了与RT相关的患者，肿瘤和系统级因素。Joinpoint回归分析计算了按年龄和设施类型分层的随时间推移的RT使用趋势，报告了年度百分比变化（APC）。结果RT率从2004年（77.2％）下降到2015年（64.3％）。这种下降最早发生，在学术机构接受治疗的老年妇女中最为明显。在学术机构中，年龄大于85岁的女性在2009年之后的APC为-5.6（95％CI-8.6，-2.4），对于80岁以下的女性-2010年之后为6.4（95％CI-9.0，-3.8）对于75-<80岁的女性，在2009年之后为-3.7（95％CI-5.6，-1.9），对于70-<75岁的女性在2009年之后为-2.4（95％CI，-3.1，-1.6）。社区设施的RT率随后下降（70、74、75-79和80-84岁年龄组分别为2011、2012和2013年）。结论基于与预期寿命和局部复发相关的因素，随着年龄段患者的变化，老年乳腺癌早期放疗率正在下降。