Radiation Therapy Program, BC Cancer Agency, Vancouver, British Columbia, Canada.
Radiation Therapy Program, BC Cancer Agency, Vancouver, British Columbia, Canada; University of British Columbia, Vancouver, British Columbia, Canada.
Int J Radiat Oncol Biol Phys. 2018 Jul 1;101(3):661-670. doi: 10.1016/j.ijrobp.2018.03.005. Epub 2018 Mar 13.
The 2014 Society of Surgical Oncology-American Society for Radiation Oncology consensus suggested "no ink on tumor" is a sufficient surgical margin for invasive breast cancer treated with breast-conserving surgery (BCS). Whether close margins <2 mm are associated with inferior outcomes remains controversial. This study evaluated 10-year outcomes by margin status in a population-based cohort treated with BCS and adjuvant radiation therapy (RT).
The subjects were 10,863 women with invasive cancer categorized as pT1 to T3, any N, and M0 referred from 2001 to 2011, an era in which the institutional policy was to re-excise close or positive margins, except in select cases. All women underwent BCS and whole-breast RT with or without boost RT. Local recurrence (LR) and breast cancer-specific survival (BCSS) were examined using competing-risk analysis in cohorts with negative (≥2 mm; n = 9241, 85%), close (<2 mm; n = 1310, 12%), or positive (tumor touching ink; n = 312, 3%) margins. Multivariable analysis and matched-pair analysis were performed.
The median follow-up period was 8 years. Systemic therapy was used in 87% of patients. Boost RT was used in 34.1%, 76.9%, and 79.5% of patients with negative, close, and positive margins, respectively. In the negative, close, and positive margin cohorts, the 10-year cumulative incidence of LR was 1.8%, 2.0%, and 1.1%, respectively (P = .759). Corresponding BCSS estimates were 93.9%, 91.8%, and 87.9%, respectively (P < .001). On multivariable analysis, close margins were not associated with increased LR (hazard ratio, 1.25; 95% confidence interval 0.79-1.97; P = .350) or reduced BCSS (hazard ratio, 1.25; 95% confidence interval 0.98-1.58, P = .071) relative to negative margins. On matched-pair analysis, close margin cases had similar LR (P = .114) and BCSS (P = .100) to negative margin controls.
Select cases with close or positive margins in this population-based analysis had similar LR and BCSS to cases with negative margins. While these findings do not endorse omitting re-excision for all cases, the data support a policy of accepting carefully selected cases with close margins for adjuvant RT without re-excision.
2014 年外科肿瘤学会-美国放射肿瘤学会共识建议，对于接受保乳手术（BCS）治疗的浸润性乳腺癌，“无肿瘤墨水”是足够的手术切缘。切缘＜2mm 是否与较差的预后相关仍存在争议。本研究通过在一个基于人群的队列中评估边缘状态，评估了 10 年的结果，该队列的患者接受了 BCS 和辅助放疗（RT）治疗。
本研究纳入了 2001 年至 2011 年间就诊的 10863 例浸润性癌症患者，这些患者为 pT1 至 T3、任何 N 和 M0 分期，在机构政策是重新切除接近或阳性边缘的情况下，除了在某些特定情况下外，边缘＜2mm 的患者也会被切除。所有女性均接受了 BCS 和全乳 RT 治疗，部分患者还接受了加量 RT 治疗。使用竞争风险分析评估阴性（≥2mm；n=9241，85%）、接近（＜2mm；n=1310，12%）或阳性（肿瘤触及墨水；n=312，3%）边缘的队列的局部复发（LR）和乳腺癌特异性生存（BCSS）。进行了多变量分析和配对分析。
中位随访时间为 8 年。87%的患者接受了系统治疗。阴性、接近和阳性边缘的患者中，分别有 34.1%、76.9%和 79.5%的患者接受了加量 RT。在阴性、接近和阳性边缘的队列中，10 年累积 LR 发生率分别为 1.8%、2.0%和 1.1%（P=0.759）。相应的 BCSS 估计值分别为 93.9%、91.8%和 87.9%（P＜0.001）。多变量分析显示，与阴性边缘相比，接近边缘并未增加 LR（风险比，1.25；95%置信区间 0.79-1.97；P=0.350）或降低 BCSS（风险比，1.25；95%置信区间 0.98-1.58，P=0.071）。配对分析显示，与阴性边缘对照相比，接近边缘的病例具有相似的 LR（P=0.114）和 BCSS（P=0.100）。
在本基于人群的分析中，选择具有接近或阳性边缘的病例与具有阴性边缘的病例具有相似的 LR 和 BCSS。虽然这些发现并不支持对所有病例都省略重新切除，但数据支持接受精心选择的具有接近边缘的病例接受辅助 RT 治疗，而无需重新切除的政策。
