Metaplastic breast cancer: A single-centre retrospective experience.

BACKGROUND: Metaplastic Breast Cancer (MpBC) is a rare disease entity accounting for less than 1% of all breast cancers. There is limited data focusing on this aggressive disease. The aim of this study was to evaluate the incidence of MpBC at a UK centre and describe the demographic variables, clinical characteristics and treatment. METHODS: Between 2017-2024, we have reviewed 23 patients diagnosed with histologically proven MpBC from the hospital cancer database. RESULTS: A total of 2097 patients were diagnosed with breast cancer in our centre between 2017-2024, of which 23 patients were diagnosed with MpBC. The incidence was 1.1%. The median age at diagnosis was 71 years, the median tumour size at presentation was 5.2 cm and twenty (87%) patients had a Grade III tumour, while three (13%) patients were Grade II. Seventeen (74%) patients were triple negative. Histologically, the most common component of MpBC was purely squamous cell metaplasia found in eight patients. With regards to treatment, twenty-one patients had surgery whereas three patients received neoadjuvant chemotherapy. Eight patients had axillary lymph nodal involvement. Eight patients passed away due to various causes. CONCLUSION: Our incidence of MpBC is consistent with literature. MpBC is an infrequently encountered pathology where the current protocols are still under evaluation. Most patients have early disease progression and poor prognosis in comparison to other breast cancer subtypes. Further research and randomised control trials are needed to determine a gold standard treatment for this disease.