[Retrospective analysis of metaplastic breast cancer cases]

Metaplastic breast tumour is a rare, aggressive, mostly triple- negative, dedifferentiated malignancy, which poorly responds to chemotherapy compared to other invasive breast tumours. Since 2000, the WHO has considered it as a separate entity among breast tumours. Given the extremely poor prognosis of the tumour, more studies are needed to establish the most effective treatment strategy supported by data to increase overall survival. The objective of our research was a retrospective analysis of 77 patients with metaplastic breast cancer treated between 01.01.2012 and 28.02.2023 at our institute. Following the descriptive statistics of the patients, the pathological or clinical response was examined in cases of 15 patients treated with neoadjuvant and 14 patients with palliative chemotherapy. Finally, we compared the overall and progression-free survival of metaplastic breast cancer patients treated at our institute with those described in the international literature. The research results, both at our institute and in the literature, are limited by the small number of cases. In our research, with similar numbers of cases as many other investigations, we obtained results close to international data, thereby supporting the collection of data and further research necessary for the most effective treatment strategy for this rare tumour.