Survival and treatment outcomes of metaplastic breast carcinoma: Single tertiary care center experience in Pakistan

BACKGROUND: Metaplastic breast carcinoma (MBC) is a rare disease with incidence of less than 1%. MBC present with a larger tumor size, less number of nodes involved, mostly undifferentiated triple negative tumors. We aimed to determine progression-free and overall survival and reported hospital-based incidence of MBC. MATERIAL AND METHODS: A retrospective closed Cohort study elicited data of 42 patients with MBC from January 2008 to December 2013; followed till August 2016. Kaplan-Meier method was applied to compute overall and progression-free survival analysis. Cox Proportional hazard ratios were computed to assess associations between survival and independent variables. RESULTS: Hospital-based incidence of MBC was 1.92% (42/2187), 95% CI [1.41-2.56]. The median age at tumor diagnosis was 54 years (range, 25u81 years). Thirty-nine (92.9%) patients had Grade III tumor. The most common histopathology was squamous (69%). The median tumor size was 4.5 cm (range, 0.8u17 cm). Nineteen (45.2%) patients had nodal involvement at diagnosis. Four patients (9.5%) had metastatic disease at presentation. Hormone receptors were positive in 19 (45.2%) patients. Her-2 neu receptor was positive in 9 (19%) patients. Sixteen (38.1%) patients had triple negative disease. Neoadjuvant and adjuvant chemotherapy was received by 10 (31.25%) and 19 (45.2%) patients respectively. Both median progression-free and overall survival was 38 months. CONCLUSION: Five-year progression-free and overall survival was 79.5% and 76.3%, respectively. We report better survival outcomes when compared to series described earlier despite our patient population presenting mostly with high grade, large tumors, and half of them exhibiting nodal and hormonal involvement.