Metaplastic Breast Cancer: Characteristics and Survival Outcomes

Abstract

Metaplastic breast cancer (MBC) is a rare neoplasm accounting for <1% of all breast cancer. We evaluated the clinical characteristics and survival outcomes of MBC. MethodsPatients diagnosed with pathologically proven MBC were reviewed from the institutional breast cancer database from 2000 to 2017. ResultsA total of 136 patients diagnosed with MBC were included in the study. The median age of the diagnosis was 60 years, and 60% of patients were stage II at diagnosis, and 22% were stage III. About two-thirds of the patients were triple-negative; 93% had nuclear grade III, and 25% had a lymphovascular invasion. Squamous differentiation (29%) was the most common histologic subtype, followed by the spindle subtype (21%). The most common distant metastases were lung (22%), followed by bone (13%). Moreover, 60% had a mastectomy, 19% had endocrine therapy, 58% had radiation, 51% received anthracycline-based chemotherapy, 26% had non-anthracycline chemotherapy, and 22% received no chemotherapy. In the entire cohort, the two-year overall survival (OS) and five-year OS were 79% and 69%, respectively, and the twoyear progression-free survival (PFS) and five-year PFS were 72% and 61%, respectively. On multivariable analysis, the stage of MBC (stage III: hazard ratio (HR), 5.065 (95% confidence interval (CI), 1.02-25.27) (p=0.048)), poor functional status (Eastern Cooperative Oncology Group (ECOG) score, 2; HR, 24.736 (95% CI, 1.92-318.73) (p=0.014)), and distant metastasis to the brain (HR, 8.453 (95% CI,) (p=0.005)) and lung (HR, 42.102 (95% CI,) (p<0.001)) were significant predictors of decreased OS. ConclusionsMBC demonstrated early disease progression and poor overall survival. The stage of MBC, decreased performance status, and metastasis to the lung and brain were independent poor prognostic factors.

A unique presentation of metaplastic breast carcinoma, NOS: A case report

“…However, due to the large tumor size at presentation, as it was mirrored in our patient, conserving surgery may be less applicable. Neoadjuvant chemotherapy has shown limited value; thus, mastectomy with axillary lymph node clearance followed by adjuvant chemotherapy is the mainstay of the management of this rare neoplasm 18,19 . Radiotherapy showed limited value in the adjuvant setting; however, there are very few studies with limited data on survival and recurrence rates postradiotherapy, and hence the need for more randomized trials on the management of this rare neoplasm.…”

Mixed Metaplastic Carcinoma of the Breast: A Case Report

“…Metaplastic breast carcinoma (MpBC) is a heterogeneous group of malignancies characterized by a nonglandular differentiation of breast tissue, including osseous, sarcomatous, or squamous histology 1,2 .…”

“…Several histologic classi cations exist under the WHO Classi cation of Breast Tumors, including epithelial only, sarcomatoid, and mixed metaplastic carcinomas as seen in our patient 3 . MpBC typically presents as a triple-negative tumor, though it has been shown to have a worse prognosis than other triplenegative breast cancers 1,2,4 . This is likely due in part to the unique biology of MPBC as well as a poor chemotherapy response being typical of MpBC [1][2][3][5][6][7][8][9] .…”

“…Due to the low reported response to neoadjuvant therapies and the resulting possibility of disease progression, current recommendations on therapy of metaplastic breast cancer include early surgical resection followed by adjuvant therapy except in tumors < 0.5 cm in size with no nodal or metastatic disease 12 . Because these tumors are usually higher grade and typically present at a later stage with a larger size, early surgical resection usually entails mastectomy 2,13 . Despite poor chemotherapy response, the addition of adjuvant radiation to surgical resection has been shown to signi cantly improve survival in patients with MPBC 1,13 .…”

“…MpBC typically presents as a triple-negative tumor, though it has been shown to have a worse prognosis than other triplenegative breast cancers 1,2,4 . This is likely due in part to the unique biology of MPBC as well as a poor chemotherapy response being typical of MpBC [1][2][3][5][6][7][8][9] . It also usually presents as a higher-grade tumor with a larger size at diagnosis than other triple-negative tumors 1,3 .…”