Sagara Yasuaki, Freedman Rachel A, Vaz-Luis Ines, Mallory Melissa Anne, Wong Stephanie M, Aydogan Fatih, DeSantis Stephen, Barry William T, Golshan Mehra
Yasuaki Sagara, Melissa Anne Mallory, Fatih Aydogan, and Mehra Golshan, Brigham and Women's Hospital; Yasuaki Sagara, Harvard T.H. Chan School of Public Health; Rachel A. Freedman, Ines Vaz-Luis, Stephen DeSantis, and William T. Barry, Dana-Farber Cancer Institute, Boston, MA; Stephanie M. Wong, McGill University Health Centre, Montreal, Quebec, Canada; and Fatih Aydogan, Cerrahpasa Medical School, Istanbul University, Istanbul, Turkey.
J Clin Oncol. 2016 Apr 10;34(11):1190-6. doi: 10.1200/JCO.2015.65.1869. Epub 2016 Feb 1.
Radiotherapy (RT) after breast-conserving surgery (BCS) is a standard treatment option for the management of ductal carcinoma in situ (DCIS). We sought to determine the survival benefit of RT after BCS on the basis of risk factors for local recurrence.
A retrospective longitudinal cohort study was performed to identify patients with DCIS diagnosed between 1988 and 2007 and treated with BCS by using SEER data. Patients were divided into the following two groups: BCS+RT (RT group) and BCS alone (non-RT group). We used a patient prognostic scoring model to stratify patients on the basis of risk of local recurrence. We performed a Cox proportional hazards model with propensity score weighting to evaluate breast cancer mortality between the two groups.
We identified 32,144 eligible patients with DCIS, 20,329 (63%) in the RT group and 11,815 (37%) in the non-RT group. Overall, 304 breast cancer-specific deaths occurred over a median follow-up of 96 months, with a cumulative incidence of breast cancer mortality at 10 years in the weighted cohorts of 1.8% (RT group) and 2.1% (non-RT group; hazard ratio, 0.73; 95% CI, 0.62 to 0.88). Significant improvements in survival in the RT group compared with the non-RT group were only observed in patients with higher nuclear grade, younger age, and larger tumor size. The magnitude of the survival difference with RT was significantly correlated with prognostic score (P < .001).
In this population-based study, the patient prognostic score for DCIS is associated with the magnitude of improvement in survival offered by RT after BCS, suggesting that decisions for RT could be tailored on the basis of patient factors, tumor biology, and the prognostic score.
保乳手术（BCS）后放疗（RT）是导管原位癌（DCIS）治疗的标准选择。我们试图根据局部复发的危险因素来确定BCS后RT的生存获益。
进行一项回顾性纵向队列研究，利用监测、流行病学与最终结果（SEER）数据识别1988年至2007年间诊断为DCIS并接受BCS治疗的患者。患者被分为以下两组：BCS+RT（RT组）和单纯BCS（非RT组）。我们使用患者预后评分模型根据局部复发风险对患者进行分层。我们采用倾向评分加权的Cox比例风险模型来评估两组之间的乳腺癌死亡率。
我们确定了32144例符合条件的DCIS患者，RT组20329例（63%），非RT组11815例（37%）。总体而言，在中位随访96个月期间发生了304例乳腺癌特异性死亡，加权队列中10年乳腺癌死亡率的累积发生率在RT组为1.8%，非RT组为2.1%（风险比，0.73；95%置信区间，0.62至0.88）。仅在核分级较高、年龄较小和肿瘤较大的患者中观察到RT组与非RT组相比生存有显著改善。RT导致的生存差异幅度与预后评分显著相关（P <.001）。
在这项基于人群的研究中，DCIS患者的预后评分与BCS后RT所带来的生存改善幅度相关，这表明RT决策可根据患者因素、肿瘤生物学和预后评分进行调整。
