Department of Radiation Oncology, Houston Methodist Hospital, Cancer Center and Research Institute, Weill Cornell Medical College, Houston, TX, USA.
Department of Radiation Oncology, University of Nebraska Medical Center, Omaha, NE, USA.
Ann Surg Oncol. 2018 Apr;25(4):928-936. doi: 10.1245/s10434-017-6316-2. Epub 2018 Jan 10.
Metaplastic breast cancer (MBC) is a rare, aggressive form of breast cancer with limited data to guide management. This study of a large, contemporary US database described national practice patterns and addressed the impact of radiotherapy (RT) on survival.
The National Cancer Data Base was queried (2004-2013) for women with non-metastatic MBC. Multivariable logistic regression ascertained factors associated with RT administration. Kaplan-Meier analysis evaluated overall survival (OS) between patients treated with either lumpectomy or mastectomy with or without RT, while substratifying patients into pT1-2N0 and pT3-4/N+ subcohorts. Cox proportional hazards modeling determined variables associated with OS.
Of 5211 total patients, 447 (9%) had lumpectomy alone, 1831 (35%) had post-lumpectomy RT, 2020 (39%) had mastectomy alone, and 913 (18%) had post-mastectomy RT (PMRT). Most patients underwent chemotherapy (79%), and mastectomy was the most common surgical approach (56%). RT delivery was impacted by many factors, including higher nodal disease (p < 0.001), but not T classification or estrogen receptor status (p > 0.05 for both). Post-lumpectomy RT was associated with higher OS in both the pT1-2N0 and pT3-4/N+ subsets (p < 0.001 for both), while PMRT was associated with OS benefits in pT3-4/N+ cases (p < 0.001), but not in pT1-2N0 cases (p = 0.259).
In the largest study to date evaluating MBC, practice patterns of surgery, systemic therapy, and RT are described. The addition of RT in the post-lumpectomy setting was associated with higher OS, in addition to pT3-4/N+ in the post-mastectomy setting. Although not implying causation, further work is required to corroborate the conclusions herein.
化生性乳腺癌（MBC）是一种罕见且侵袭性的乳腺癌，其管理数据有限。本研究对美国一个大型当代数据库进行了研究，描述了全国的实践模式，并探讨了放疗（RT）对生存的影响。
从国家癌症数据库（2004-2013 年）中检索出非转移性 MBC 女性患者。多变量逻辑回归确定了与 RT 治疗相关的因素。通过 Kaplan-Meier 分析评估了接受保乳手术或乳房切除术联合或不联合 RT 的患者的总生存（OS），同时将患者分为 pT1-2N0 和 pT3-4/N+亚组。Cox 比例风险模型确定了与 OS 相关的变量。
在 5211 名患者中，447 名（9%）接受了单纯保乳手术，1831 名（35%）接受了保乳术后 RT，2020 名（39%）接受了单纯乳房切除术，913 名（18%）接受了乳房切除术后 RT（PMRT）。大多数患者接受了化疗（79%），最常见的手术方式是乳房切除术（56%）。RT 的应用受到许多因素的影响，包括淋巴结疾病程度更高（p<0.001），但与 T 分类或雌激素受体状态无关（两者均为 p>0.05）。保乳术后 RT 与 pT1-2N0 和 pT3-4/N+亚组的 OS 提高相关（两者均为 p<0.001），而 PMRT 与 pT3-4/N+病例的 OS 获益相关（p<0.001），但与 pT1-2N0 病例无关（p=0.259）。
在迄今评估 MBC 的最大研究中，描述了手术、系统治疗和 RT 的实践模式。保乳术后加用 RT 与 OS 提高相关，pT3-4/N+ 患者在乳房切除术后加用 RT 与 OS 提高相关。虽然不能暗示因果关系，但需要进一步的工作来证实本文的结论。
