Yao Nengliang, Mackley Heath B, Anderson Roger T, Recht Abram
Department of Health Policy and Administration, Pennsylvania State University, University Park, PA 16802, USA.
Brachytherapy. 2013 Jul-Aug;12(4):293-302. doi: 10.1016/j.brachy.2013.01.168. Epub 2013 Mar 7.
Despite growing utilization of accelerated partial breast irradiation using brachytherapy (APBI-Brachy) for elderly breast cancer patients, there are limited data from randomized Phase III trials to support its routine use. This study uses population-based data to examine whether APBI-Brachy results in comparable survival rates compared with whole breast irradiation (WBI).
A sample of 29,647 female patients diagnosed with nonmetastatic breast cancer in 2002-2007 treated with breast-conserving surgery and radiotherapy was identified in the Surveillance, Epidemiology, and End Results Program-Medicare data set. Log-rank tests, Cox proportional hazards models, instrumental variable analysis, and subgroup analysis were used to study the comparative effectiveness of APBI-Brachy and WBI.
During a median followup of 3.6 and 4.8 years, 123 (7.7%) and 3438 (13.6%) patients died after APBI-Brachy and WBI, respectively. Recurrence-free survival (p = 0.9711) and overall survival rates (p = 0.0551) did not differ significantly between the two radiation modalities. After accounting for tumor characteristics, patient characteristics, community factors, and comorbidities, the recurrence-free survival (hazard ratio, 1.05; 95% confidence interval, 0.90-1.23; p = 0.5125) and overall survival (hazard ratio, 0.87; 95% confidence interval, 0.72-1.04; p = 0.1332) rates were still not significantly different between patients treated with APBI-Brachy and WBI.
Partial breast brachytherapy and WBI resulted in similar recurrence-free and overall survival rates in this cohort of elderly breast cancer patients, even after adjustment for the more favorable characteristics of patients in the former group. These findings will need to be confirmed by the randomized trials comparing these modalities.
尽管近距离放射疗法加速部分乳腺照射（APBI-Brachy）在老年乳腺癌患者中的应用日益增多，但来自随机III期试验的数据有限，无法支持其常规使用。本研究使用基于人群的数据来检验与全乳照射（WBI）相比，APBI-Brachy是否能带来相当的生存率。
在监测、流行病学和最终结果计划-医疗保险数据集中，确定了2002年至2007年期间接受保乳手术和放疗的29647例诊断为非转移性乳腺癌的女性患者样本。采用对数秩检验、Cox比例风险模型、工具变量分析和亚组分析来研究APBI-Brachy和WBI的比较疗效。
在中位随访3.6年和4.8年期间，分别有123例（7.7%）和3438例（13.6%）患者在接受APBI-Brachy和WBI后死亡。两种放疗方式的无复发生存率（p = 0.9711）和总生存率（p = 0.0551）无显著差异。在考虑肿瘤特征、患者特征、社区因素和合并症后，接受APBI-Brachy和WBI治疗的患者的无复发生存率（风险比，1.05；95%置信区间，0.90 - 1.23；p = 0.5125）和总生存率（风险比，0.87；95%置信区间，0.72 - 1.04；p = 0.1332）仍无显著差异。
在这组老年乳腺癌患者中，即使对前一组患者更有利的特征进行调整后，部分乳腺近距离放射疗法和WBI的无复发生存率和总生存率仍相似。这些发现需要通过比较这些方式的随机试验来证实。
