乳房切除术后大多数不需要放疗

　　编者按：所有指南一致认为，对于伴有1～3个淋巴结阳性（N1）的T1～2期乳腺肿瘤，乳房切除术后放疗可以减少近处（局部和淋巴引流区域）复发，但是权衡放疗潜在的危害，建议仅对风险最高的患者进行乳房切除术后放疗。

　　2018年3月21日，美国乳腺外科医师学会和肿瘤外科学会《肿瘤外科学年鉴》在线发表纽约纪念医院斯隆凯特林癌症中心（美国最早、最大的肿瘤医院兼癌症研究机构）的回顾研究报告，确定了接受现代化疗方案治疗的T1～2N1患者乳房切除术后近处复发风险、乳房切除术后未放疗的近处复发预测因素，发现T1～2期肿瘤伴有1～3个淋巴结阳性的乳腺癌患者乳房切除术后大多数不需要放疗。

　　该回顾研究入组1995～2006年接受乳房切除术的T1～2N1乳腺癌患者1087例，其中未放疗924例（85%）、放疗163例（15%）。通过卡方检验，比较两组患者的临床病理特征，并且通过生存曲线分析和多因素比例风险回归分析，确定近处复发率、无复发生存和总生存。

　　结果，经过随访0～21年（中位10.8年）确诊近处复发63例，其中未放疗组56例、放疗组7例，10年近处复发率分别为4.0%、7.0%。

　　放疗组与未放疗组的患者相比：

• 年龄较小（P=0.019）

• 肿瘤较大（P=0.0013）

• 组织学分级较高（P=0.029）

• 阳性淋巴结较多（P<0.0001）

• 淋巴管浸润较多（P<0.0001）

• 淋巴结包膜外侵犯较多（P<0.0001）

• 肉眼可见淋巴结转移较多（P<0.0001）

• 近处复发率相似（P=0.32）

• 无复发生存相似（P=0.46）

• 总生存相似（P=0.44）

　　根据多因素比例风险回归分析表明，乳房切除术后不放疗的近处复发相关因素：

• 年龄＜40岁（P<0.0001）

• 淋巴管浸润（P<0.0001）

　　因此，该研究结果与指南一致，该中心T1～2N1乳腺癌患者乳房切除术后未放疗占85%，同时保持较低的近处复发率。对于乳房切除术后未放疗的患者，年龄＜40岁且存在淋巴管浸润，与近处复发显著相关，需要加强随访监测。

Ann Surg Oncol. 2018 Mar 21. [Epub ahead of print]

Most Breast Cancer Patients with T1-2 Tumors and One to Three Positive Lymph Nodes Do Not Need Postmastectomy Radiotherapy.

Shirin Muhsen, Tracy-Ann Moo, Sujata Patil, Michelle Stempel, Simon Powell, Monica Morrow, Mahmoud El-Tamer.

Memorial Sloan Kettering Cancer Center, New York, USA.

BACKGROUND/OBJECTIVE: Guidelines concur that postmastectomy radiation therapy (PMRT) in T1-2 tumors with one to three positive (+) lymph nodes (LNs) decreases locoregional recurrence (LRR) but advise limiting PMRT to patients at highest risk to balance against potential harms. In this study, we identify the risks of LRR after mastectomy in patients with T1-2N1 disease, treated with modern chemotherapy, and identify predictors of LRR when omitting PMRT.

METHODS: Patients with T1-2N1 breast cancer undergoing mastectomy between 1995 and 2006 were categorized by receipt of PMRT. The Chi square test compared the clinicopathologic features between both groups, and Kaplan-Meier and Cox regression analysis was used to determine the rates of LRR, recurrence-free survival (RFS), and overall survival (OS).

RESULTS: Overall, 1087 patients (924 no PMRT, 163 PMRT) were included in the study, with a median follow-up of 10.8 years (range 0-21). We identified 63 LRRs (56 no PMRT, 7 PMRT), and 10-year rates of LRR with and without PMRT were 4.0% and 7.0%, respectively. Patients receiving PMRT were younger (p=0.019), had larger tumors (p=0.0013), higher histologic grade (p=0.029), more positive LNs (p<0.0001), lymphovascular invasion (LVI) (p<0.0001), extracapsular nodal extension (p<0.0001), and macroscopic LN metastases (p<0.0001). There was no difference in LRR, RFS, or OS between groups. On multivariate analysis, age<40 years (p<0.0001) and LVI (p<0.0001) were associated with LRR in those not receiving PMRT.

CONCLUSION: Consistent with the guidelines, 85% of patients with T1-2N1 were spared PMRT at our center, while maintaining low LRR. Age<40 years and the presence of LVI are significantly associated with LRR in those not receiving PMRT.

DOI: 10.1245/s10434-018-6422-9