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

PURPOSE: 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.

PATIENT AND METHODS: 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.

RESULTS: 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%.

CONCLUSION: 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.