乳腺癌乳房切除术后谁可免去放疗？
长期以来，对于肿瘤>5厘米或淋巴结转移≥4枚早期乳腺癌患者，放疗一直是乳房切除术后的标准治疗方法。不过，对于肿瘤≤5厘米（T1-2）或淋巴结转移1～3枚（N1）早期乳腺癌患者，乳房切除术后放疗的必要性仍然存在争议。
2021年9月6日，施普林格自然旗下《乳腺癌研究与治疗》在线发表复旦大学附属肿瘤医院王小方、张丽、张晓萌、罗菊锐、汪宣伊、陈星星、杨昭志、梅欣、俞晓立、章真、郭小毛、邵志敏、马金利等学者的研究报告，对T1-2N1期乳腺癌乳房切除术后±放疗的局部区域复发影响因素进行了分析，并对乳房切除术后哪些患者可免去放疗进行了探讨。
该单中心回顾研究对2006年1月～2012年12月复旦大学附属肿瘤医院连续1474例病理T1-2N1期乳腺癌乳房切除术后患者的病历数据进行回顾分析，其中乳房切除术后放疗患者663例。采用生存时间曲线计算局部区域控制和无病生存，通过多因素比例风险回归模型进行单因素和多因素分析以确定复发风险因素。
结果，截至2020年10月31日，随访5～168个月（中位93个月）期间，78例（5.3%）局部区域控制失败，220例（14.9%）出现局部区域或远处复发，整个队列的7.7年局部区域控制率和无病生存率分别为94.9%和85.4%。
乳房切除术后放疗与未放疗相比：
7.7年局区控制率较高：96.6%比93.4%（P=0.005）
7.7年无病生存率相似：84.2%比86.7%（P=0.335）
多因素分析表明，局部区域复发的独立风险因素包括：
未放疗与放疗相比：局部区域复发风险高3.36倍（95%置信区间：2.11～6.14，P<0.001）
年龄≤40岁比>40岁：局部区域复发风险高2.02倍（95%置信区间：1.17～3.50，P=0.012）
组织学3级比1～2级：局部区域复发风险高1.97倍（95%置信区间：1.24～3.12，P=0.004）
淋巴结转移2～3枚比1枚：局部区域复发风险高2.46倍（95%置信区间：1.51～3.99，P<0.001）
肿瘤大小3～5厘米比0～3厘米：局部区域复发风险高1.73倍（95%置信区间：1.01～2.97，P=0.045）
根据上述风险因素，可将患者分为3组：
低风险组：有0个风险因素
中风险组：有1个风险因素
高风险组：有2～4个风险因素
乳房切除术后未放疗与放疗相比，7.7年局部区域控制率：
低风险组：97.7%比98.9%（P=0.233）
中风险组：95.3%比98.0%（P=0.092）
高风险组：80.3%比94.8%（P<0.001）
乳房切除术后未放疗与放疗相比，7.7年无病生存率：
低风险组：89.5%比93.0%（P=0.309）
中风险组：85.3%比88.0%（P=0.388）
高风险组：66.6%比80.5%（P=0.002）
因此，该单中心回顾研究结果表明，对于T1-2N1期乳腺癌患者，乳房切除术后局部区域控制较差的风险因素包括年轻、组织学3级、淋巴结转移2～3枚、肿瘤大小3～5厘米。对于仅有0～1个风险因素的T1-2N1期乳腺癌患者，乳房切除术后或可考虑免去放疗，故有必要进一步开展多中心前瞻研究进行验证。
Breast Cancer Res Treat. 2021 Sep 6. Online ahead of print.
Impact of clinical-pathological factors on locoregional recurrence in mastectomy patients with T1-2N1 breast cancer: who can omit adjuvant radiotherapy?
Xiaofang Wang, Li Zhang, Xiaomeng Zhang, Jurui Luo, Xuanyi Wang, Xingxing Chen, Zhaozhi Yang, Xin Mei, Xiaoli Yu, Zhen Zhang, Xiaomao Guo, Zhimin Shao, Jinli Ma.
Fudan University Shanghai Cancer Center, Shanghai, China; Shanghai Medical College, Fudan University, Shanghai, China; Shanghai Key Laboratory of Radiation Oncology, Shanghai, China.
PURPOSE: Postmastectomy radiation therapy (PMRT) in T1-T2 tumors with 1-3 positive axillary lymph nodes (ALNs) is controversial. This study was to identify prognostic factors of locoregional control (LRC) following mastectomy with or without PMRT for patients with T1-2N1 breast cancer and to discuss the selection of patients who might omit PMRT.
MATERIALS AND METHODS: Between January 2006 and December 2012, the data of 1474 postmastectomy patients staged pT1-2N1 were analyzed. PMRT was applied in 663 patients. LRC and disease-free survival (DFS) were calculated using the Kaplan-Meier method. Cox regression model was applied in the univariate and multivariate analyses to recognize the recurrence risk factors.
RESULTS: With the median follow-up duration of 93 months (range, 5-168 months), 78 patients (5.3%) failed to secure LRC and 220 patients (14.9%) experienced any recurrence. The 7.7-year LRC and DFS was 94.9% and 85.4% respectively in the entire cohort. PMRT significantly improved 7.7-year LRC from 93.4% to 96.6% (P=0.005), but not the DFS (P=0.335). Multivariate analysis revealed that PMRT was an independent prognostic factor of LRC (P<0.001), meanwhile, age≤40 years (P=0.012), histological grade 3 (P=0.004), 2-3 positive nodes (P<0.001) and tumor size of 3-5 cm (P=0.045) were significantly associated with decreased LRC. The 7.7-year LRC for patients with 0, 1, and 2-4 risk factors was 97.7% / 98.9% (P=0.233), 95.3% / 98.0% (P=0.092), and 80.3% / 94.8% (P<0.001) in the non-PMRT and PMRT group, respectively.
CONCLUSIONS: In patients with T1-2N1 breast cancer, clinical-pathological factors including young age, histological grade 3, 2-3 positive nodes, and tumor size of 3-5 cm were identified to be predictors of a poorer LRC following mastectomy. Patients with 0-1 risk factor might consider the omission of PMRT.
KEYWORDS: Breast cancer; Early stage; PMRT; Prognostic factors
DOI: 10.1007/s10549-021-06378-2