Division of Radiation Oncology, McGill University Health Centre, Montreal, QC, Canada.
Int J Radiat Oncol Biol Phys. 2012 Feb 1;82(2):e153-8. doi: 10.1016/j.ijrobp.2011.03.045. Epub 2011 Jun 12.
Local recurrence (LR) of ductal carcinoma in situ (DCIS) is reduced by whole-breast irradiation after breast-conserving surgery (BCS). However, the benefit of adding a radiotherapy boost to the surgical cavity for DCIS is unclear. We sought to determine the impact of the boost on LR in patients with DCIS treated at the McGill University Health Centre.
A total of 220 consecutive cases of DCIS treated with BCS and radiotherapy between January 2000 and December 2006 were reviewed. Of the patients, 36% received a radiotherapy boost to the surgical cavity. Median follow-up was 46 months for the boost and no-boost groups. Kaplan-Meier survival analyses and Cox regression analyses were performed.
Compared with the no-boost group, patients in the boost group more frequently had positive and <0.1-cm margins (48% vs. 8%) (p < 0.0001) and more frequently were in higher-risk categories as defined by the Van Nuys Prognostic (VNP) index (p = 0.006). Despite being at higher risk for LR, none (0/79) of the patients who received a boost experienced LR, whereas 8 of 141 patients who did not receive a boost experienced an in-breast LR (log-rank p = 0.03). Univariate analysis of prognostic factors (age, tumor size, margin status, histological grade, necrosis, and VNP risk category) revealed only the presence of necrosis to significantly correlate with LR (log-rank p = 0.003). The whole-breast irradiation dose and fractionation schedule did not affect LR rate.
Our results suggest that the use of a radiotherapy boost improves local control in DCIS and may outweigh the poor prognostic effect of necrosis.
保乳手术后（BCS）进行全乳照射可降低导管原位癌（DCIS）的局部复发（LR）。然而，对于 DCIS 患者，在手术腔中添加放射治疗增敏剂量的益处尚不清楚。我们旨在确定麦吉尔大学健康中心治疗的 DCIS 患者中，增敏剂量对 LR 的影响。
共回顾了 2000 年 1 月至 2006 年 12 月期间接受 BCS 和放疗的 220 例连续 DCIS 病例。其中，36%的患者接受了手术腔放射治疗增敏。增敏组和非增敏组的中位随访时间分别为 46 个月。进行 Kaplan-Meier 生存分析和 Cox 回归分析。
与非增敏组相比，增敏组患者的阳性且<0.1cm 切缘（48%对 8%）（p < 0.0001）和 Van Nuys 预后指数（VNP）较高的风险类别（p = 0.006）更为常见。尽管 LR 风险较高，但接受增敏的 79 例患者中无一例（0/79）发生 LR，而未接受增敏的 141 例患者中有 8 例发生乳房内 LR（对数秩 p = 0.03）。对预后因素（年龄、肿瘤大小、切缘状态、组织学分级、坏死和 VNP 风险类别）的单因素分析显示，只有坏死与 LR 显著相关（对数秩 p = 0.003）。全乳照射剂量和分割方案不影响 LR 率。
我们的结果表明，放射治疗增敏的使用可改善 DCIS 的局部控制，可能超过坏死的不良预后影响。
