Metaplastic breast carcinoma: case series and review of the literature

Metaplastic breast carcinoma (MpBC) is a rare disease entity, accounting for less than 1% of all breast carcinomas. Furthermore, it is a heterogenous disease with different subgroups, including malignant epithelial (carcinoma) and stromal (sarcoma) features. Here we evaluated, retrospectively, 14 female MpBC patients admitted to Ankara Oncology Training and Research Hospital between 2005 and 2011. Median age was 45.5 (range:16.0-76.0) and tumor size 57.5 mm (range: 20.0-80.0 mm). Histopathological subtypes were as follows: 5 carcinosarcoma, 5 squamous and 4 adenosquamous carcinoma. All but one with upfront lung metastasis, had their primary breast tumor operated. Axillary lymph nodes were involved in 64.3%. The most common sites of metastasis were lungs and brain. Chemotherapy including antracycline, taxane and even platinium was planned for adjuvant, neoadjuvant and palliative purposes in 9, 3 and 1 patient, respectively. Median cycles of chemotherapy was 6 (range:4-8). Median follow-up of the patients was 52 months (95%CI 10.4-93.6 month). Median 3 year progression free survival (PFS) and overall survival (OS) in this patients cohort were 33% and 56%, respectively. In conclusion, MpBC is a rare and orphan disease without standardized treatment approaches and the prognosis is poor so that larger studies to investigate different treatment schedules are urgently needed.