Metaplastic breast carcinoma: Analysis of 31 cases from a single institute.

Metaplastic carcinoma of the breast (MBC) accounts for less than 1% of all mammary tumors. This study aimed at revision of the clinico-pathological features, treatment strategy and outcome for MBC patients presented to the Kuwait Cancer Control Center to define the clinical behavior and prognostic factors of these neoplasms in our population.Thirty-one patients were retrieved from our surgical pathology registry between January 2005 and December 2014. Medical records were revised regarding the clinico-pathological features and treatment outcome.MBC represented 1% of our breast cancer patients. The median age was 50years (32-70years). Two patients presented with metastatic disease. Mastectomy was done for 24 patients and 7 had conservative surgery. The median tumor size at the time of surgery was 5.5cm (1.5-12cm). Axillary nodes were negative in 21 patients (N0), 5 patients were N1, 4 patients were N2 and one Nx. Three histological subtypes were presented: carcinosarcoma (7 cases), squamous cell carcinoma/IDC with squamous differentiation (15 cases), high grade IDC with metaplastic differentiation (9 cases). Immunohistochemically, 26 were negative hormone receptors and all were negative for Her2/neu overexpression. Chemotherapy was used in 28 patients, and adjuvant radiotherapy in 24 patients. The median follow-up was 47months (7-126months), six patients lost follow-up. The 5-year OS was 69% and 5-year PFS was 50%.MBC is a rare entity among breast carcinoma in Kuwait. Most of the cases present with poor prognostic indicators and often show lack of expression of ER, PR and Her2/neu.