Department of Radiation Oncology, University of Michigan, Ann Arbor, Michigan.
Department of Biostatistics, University of Michigan, Ann Arbor, Michigan.
Int J Radiat Oncol Biol Phys. 2022 Mar 15;112(4):853-860. doi: 10.1016/j.ijrobp.2021.10.012. Epub 2021 Oct 28.
Questions remain about whether moderately hypofractionated whole-breast irradiation is appropriate for patients with triple-negative breast cancer.
Using the prospective database of a multicenter, collaborative quality improvement consortium, we identified patients with node-negative, triple-negative breast cancer who received whole-breast irradiation with either moderate hypofractionation or conventional fractionation. Using inverse probability of treatment weighting (IPTW), we compared outcomes using the Kaplan-Meier product-limit estimation method with Cox regression models estimating the hazard ratio for time-to-event endpoints between groups.
The sample included 538 patients treated at 18 centers in 1 state in the United States, of whom 307 received conventionally fractionated whole-breast irradiation and 231 received moderately hypofractionated whole-breast irradiation. The median follow-up time was 5.0 years (95% confidence interval [CI], 4.77-5.15 years). The 5-year IPTW estimates for freedom from local recurrence were 93.6% (95% CI, 87.8%-96.7%) in the moderate hypofractionation group and 94.4% (95% CI, 90.3%-96.8%) in the conventional fractionation group. The hazard ratio was 1.05 (95% CI, 0.51-2.17; P = .89). The 5-year IPTW estimates for recurrence-free survival were 87.8% (95% CI, 81.0%-92.4%) in the moderate hypofractionation group and 88.4% (95% CI 83.2%-92.1%) in the conventional fractionation group. The hazard ratio was 1.02 (95% CI, 0.62-1.67; P = .95). The 5-year IPTW estimates for overall survival were 96.6% (95% CI, 92.0%-98.5%) in the moderate hypofractionation group and 93.4% (95% CI, 88.7%-96.1%) in the conventional fractionation group. The hazard ratio was 0.65 (95% CI, 0.30-1.42; P = .28).
Analysis of outcomes in this large observational cohort of patients with triple-negative, node-negative breast cancer treated with whole-breast irradiation revealed no differences by dose fractionation. This adds evidence to support the use of moderate hypofractionation in patients with triple-negative disease.
关于局部晚期三阴性乳腺癌患者是否适合接受适度分割全乳放疗，目前仍存在疑问。
利用多中心合作质量改进联盟的前瞻性数据库，我们确定了接受全乳放疗的淋巴结阴性、三阴性乳腺癌患者，他们接受了适度分割或常规分割。采用逆概率治疗加权法（IPTW），我们使用 Kaplan-Meier 乘积限估计法比较两组之间的生存时间终点的风险比，并使用 Cox 回归模型进行估计。
该样本包括在美国一个州的 18 个中心治疗的 538 例患者，其中 307 例接受常规分割全乳放疗，231 例接受适度分割全乳放疗。中位随访时间为 5.0 年（95%置信区间[CI]：4.77-5.15 年）。在适度分割组中，5 年 IPTW 估计的无局部复发率为 93.6%（95%CI：87.8%-96.7%），在常规分割组中为 94.4%（95%CI：90.3%-96.8%）。风险比为 1.05（95%CI：0.51-2.17；P=0.89）。在适度分割组中，5 年 IPTW 估计的无复发生存率为 87.8%（95%CI：81.0%-92.4%），在常规分割组中为 88.4%（95%CI：83.2%-92.1%）。风险比为 1.02（95%CI：0.62-1.67；P=0.95）。在适度分割组中，5 年 IPTW 估计的总生存率为 96.6%（95%CI：92.0%-98.5%），在常规分割组中为 93.4%（95%CI：88.7%-96.1%）。风险比为 0.65（95%CI：0.30-1.42；P=0.28）。
对接受全乳放疗的三阴性、淋巴结阴性乳腺癌患者进行的这项大型观察队列研究的结果分析显示，剂量分割方式无差异。这为三阴性疾病患者使用适度分割提供了更多证据支持。
