Metaplastic Breast Cancer: To Radiate or Not to Radiate?

Abstract

BackgroundThe role of radiation therapy (RT) is unclear for metaplastic breast cancer (MBC). We hypothesized that RT would improve overall survival (OS) and disease-specific survival (DSS).Materials and MethodsWe used the Surveillance, Epidemiology, and End Results (SEER) database to identify MBC patients diagnosed from1988 to 2006. Univariate analyses of patient, tumor, and treatment-specific factors on OS and DSS were performed using the Kaplan–Meier method and differences among survival curves assessed via log rank. Variables assessed included patient age, race/ethnicity, histologic subtype, tumor grade, T stage, N stage, M stage, hormone receptor status, surgery type, and use of RT. Cox proportional hazards models used all univariate covariates. Risks of mortality were reported as hazard ratios (HR) with 95% confidence intervals (95% CI); significance was set at P ≤ 0.05.ResultsAmong 1501 patients, RT was given to 580 (38.6%). Ten-year OS and DSS were 53.2, and 68.3%, respectively. In the overall analysis, RT provided an OS (HR 0.64; 95% CI, 0.51–0.82; P < 0.001) and DSS (HR 0.74; CI, 0.56–0.96; P < 0.03) benefit. When patients were stratified according to type of surgery, RT provided an OS but not a DSS benefit to lumpectomy (HR 0.51; CI, 0.32–0.79, P < 0.01) and mastectomy patients (HR 0.67; CI, 0.49–0.90; P < 0.01).ConclusionsOur findings support the use of RT for patients with MBC following lumpectomy or mastectomy. These retrospective findings should be confirmed in a prospective clinical trial.

Current Progress in the Treatment of Metaplastic Breast Carcinoma

“…BRCA1 pathway, PTEN and TOP2A etc. had been shown down-regulated by genomic profiling (Tseng and Martinez, 2011). These theories may help explain the sensitivity to external beam RT.…”

“…Moreover, the overall survival (OS) or disease-free survival (DFS) was also similar (Dave et al, 2006;Pezzi et al, 2007;Tseng and Martinez, 2011). Likewise, when known prognostic factors (eg, histological subtype and tumor grade) were controlled, MBC patients treated with MRM or lumpectomy had similar OS or DFS (Sneige et al, 2001;Tseng and Martinez, 2011;Nonnis et al, 2012). It appears that the prognosis is not affected by the type of surgical treatment.…”

“…Axillary lymph node (ALN) involvement or metastases was found in about 20% of MBC patients (Pezzi et al, 2007;Tseng and Martinez, 2011), and axillary staging had traditionally been performed with axillary lymph node dissection (ALND). Axillary lymph node involvement was consistently absent in spindle cell carcinoma (SCC) patients who underwent ALND, and no axillary node invasion was documented in patients with local recurrence (Bauer et al, 1984;Oberman, 1987;Sneige et al, 2001), which suggests that ALND is not necessary in patients with SCC.…”

“…However, data were limited regarding the role of RT for MBC (Gutman et al, 1995;Dave et al, 2006). Recently, utilizing the Surveillance, Epidemiology, and End Results (SEER) database, the findings from Tseng and Martinez (Tseng and Martinez, 2011) supported that adjuvant RT improved both OS and DFS for all MBC patients regardless of the type of operation (lumpectomy versus MRM). According to the results of multivariate analysis, the use of RT had a better survival benefit for patients received lumpectomy compared with mastectomy.…”

Metaplastic Breast Cancer Presenting as a Breast Abscess

“…In this study, we review the Mayo Clinic experience in the systemic treatment of metaplastic breast cancer. We also review all published English-language case series containing 10 or more patients [1][2][3][4].…”