Unique clinicopathological features of metaplastic breast carcinoma compared with invasive ductal carcinoma and poor prognostic indicators

Abstract

BackgroundMetaplastic breast carcinoma is a rare aggressive malignant neoplasm. The purposes of this study are to review the pathologic features and clinical outcomes of metaplastic breast carcinoma compared to invasive ductal carcinoma and to evaluate the prognosis of metaplastic breast carcinoma.MethodsThe cases of 55 patients with metaplastic breast carcinomapresenting between 1991 and 2006 were analyzed and compared to the cases of 767 age-matched patients with invasive ductal carcinoma from the same time period.ResultsThe group of patients with metaplastic breast carcinoma presented with a larger tumor size, lower lymph node involvement, higher percentage of triple-negative (estrogen receptor-, progesterone receptor- and human epidermal growth factor receptor-2-negative) cases, and Ki-67 over-expression compared with the group of patients with invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Patients in the metaplastic breast carcinoma group tended to have more local (often chest wall) recurrences (P = 0.038) and distant (often lung) metastases (P = 0.001) than those in the invasive ductal carcinomas group. The prognosis of metaplastic breast carcinoma was poorer than that of invasive ductal carcinoma and triple-negative invasive ductal carcinomas; the 5-year overall survival rate was 54.5% in metaplastic breast carcinoma versus 85.1% in invasive ductal carcinoma, and 73.3% in triple-negative invasive ductal carcinomas (P <0.001). The 5-year disease-free survival rate was 45.5% in metaplastic breast carcinoma versus 71.2% in invasive ductal carcinoma, and 60.3% in triple-negative invasive ductal carcinomas (P <0.001). Multivariate analysis revealed tumor size larger than 5.0 cm, lymph node involvement and Ki-67≥14% were significantly related to 5-year overall survival (P = 0.010; P = 0.010; P = 0.035) and 5-year disease-free survival (P = 0.020; P = 0.018; P = 0.049).ConclusionsMetaplastic breast carcinoma shows a poorer prognosis than both invasive ductal carcinoma and triple-negative invasive ductal carcinomas. Tumor size larger than 5.0 cm, lymph node involvement and Ki-67 ≥14% indicate a poor prognosis in patients with metaplastic breast carcinoma.

Metaplastic carcinoma of the breast: Imaging and pathological features

“…Core needle biopsy and aspiration cytology may aid in a pre-operative diagnosis, but the probability of misdiagnosis would increase in the presence of hemorrhage or necrosis due to inadequate sampling or a poor choice of puncture region (1). In the majority of cases, the transition foci between metaplastic carcinoma and invasive ductal carcinoma were only observed following surgical biopsy (1,3,9,11). Therefore, extensive sampling by surgical biopsy and immunohistochemical examination should be performed to avoid misdiagnosis.…”

“…Therefore, traditional surgery is the preferred treatment choice (2). However, Song et al (3) identified that local tumor recurrence was common following a simple mastectomy; therefore, surgical techniques, including radical mastectomy and modified radical mastectomy, such as axillary dissection, may improve the prognosis and survival rate of a patient. Additionally, local and distant metastases are more frequent than other types of breast cancer during the follow-up subsequent to surgery (1).…”

“…Metaplastic carcinoma exhibits the metaplastic transformation of glandular epithelium to squamous epithelium and mesenchymal tissue, and accounts for <5% of all breast cancers (2) and may contain glandular and non-glandular components with mixed epithelial and mesenchymal tissue. Involvement of the axillary lymph node is rare, with hematogenous metastasis occurring more commonly in cases of metaplastic carcinoma (1,3). Metaplastic carcinoma demonstrates a poorer prognosis and a higher risk of recurrence compared with other types of breast cancer (3).…”

“…Involvement of the axillary lymph node is rare, with hematogenous metastasis occurring more commonly in cases of metaplastic carcinoma (1,3). Metaplastic carcinoma demonstrates a poorer prognosis and a higher risk of recurrence compared with other types of breast cancer (3). It typically presents as triple negative, therefore the effects of hormonotherapy are limited (3,4).…”

“…Metaplastic carcinoma demonstrates a poorer prognosis and a higher risk of recurrence compared with other types of breast cancer (3). It typically presents as triple negative, therefore the effects of hormonotherapy are limited (3,4). Due to the heterogeneity of metaplastic carcinoma and its increased complexity compared with more common types of breast cancer, mixed chemotherapy regimens and dose schedules may be more effective and appropriate (2).…”