J Radiat Res. 2022 Jan 20;63(1):80-87. doi: 10.1093/jrr/rrab103.
We hypothesize that there is a risk of ipsilateral breast tumor recurrence (IBTR) in surgical margin-free invasive ductal carcinoma (IDC) in the presence of ductal carcinoma in situ (DCIS) component affecting surgical margins in early stage. From 1990 to 2014, 343 patients with IDC in which the DCIS component constitute have received radiotherapy (RT) following breast-conserving surgery (BCS). All patients received whole breast irradiation with a prescribed dose of 50 Gy in 20 fractions (four times a week). This one-arm cohort with boost RT (253 patients) was compared for IBTR with a non-cohort group receiving no boost RT because of freedom from positive margins (90 patients). Median observation months were 98 (boost group) vs 119 (no boost group), respectively. The 15-year local recurrence-free survival (LRFS) rates were 98.5% and 85.6% in the boost and no boost groups, respectively (Cox proportional hazards model univariate analysis; p = 0.013, HR 0.13). Similarly, for other background factors, there was a significant difference in the LRFS between age groups. The 15-year LRFS rate was 91.8% in patients aged 45 years or younger and 94.6% in patients older than 46 years (p = 0.031, HR 0.21), respectively. Only these two factors were independently significant in Cox proportional hazards model multivariate analysis. IBTR risk in margin-free IDC with DCIS component was independently decreased by boost RT in the cohort setting. Tumor size, extensive intraductal component (EIC), boost dose, the presence of lymph node (LN) metastasis and hormonal therapy were not IBTR risk factors in this study.
我们假设在早期，当导管原位癌（DCIS）成分影响手术切缘时，无手术切缘的浸润性导管癌（IDC）存在同侧乳房肿瘤复发（IBTR）的风险。1990 年至 2014 年间，343 例 IDC 患者的 DCIS 成分接受了保乳手术后的放射治疗（RT）。所有患者均接受全乳腺照射，处方剂量为 50Gy，20 个分次（每周 4 次）。该单臂队列接受了局部加量 RT（253 例），并与未接受局部加量 RT 且切缘无肿瘤（90 例）的非队列组进行了 IBTR 比较。中位观察时间分别为 98 个月（加量组）和 119 个月（无加量组）。加量组和无加量组的 15 年局部无复发生存率（LRFS）分别为 98.5%和 85.6%（Cox 比例风险模型单因素分析；p=0.013，HR 0.13）。同样，对于其他背景因素，LRFS 在年龄组之间也存在显著差异。年龄在 45 岁或以下的患者 15 年 LRFS 率为 91.8%，年龄在 46 岁以上的患者为 94.6%（p=0.031，HR 0.21）。只有这两个因素在 Cox 比例风险模型多因素分析中是独立显著的。在队列研究中，无切缘 IDC 伴 DCIS 成分的患者接受局部加量 RT 可独立降低 IBTR 风险。肿瘤大小、广泛的导管内成分（EIC）、局部加量剂量、淋巴结（LN）转移的存在和激素治疗不是本研究的 IBTR 危险因素。
