Current approaches to the management of neuroendocrine breast carcinoma (NEBC): a review

Neuroendocrine breast carcinoma (NEBC), an infrequent malignancy, accounts for 2–5% of all invasive breast cancer cases. The minimal occurrence of these tumours has resulted in knowledge primarily acquired from unique case reports or short retrospective studies. NEBC is diagnosed by identifying morphological characteristics related to gastrointestinal tracts and lung neuroendocrine tumors and neuroendocrine biomarkers. Recent investigations have revealed that NEBCs, despite being hormone receptor-positive and HER2-negative, may have adverse outcomes in comparison to invasive breast cancer lacking neuroendocrine differentiation. The primary approach for early NEBC is surgical intervention, which is identical to invasive non-special histological carcinoma treatment. Anthracycline-and-taxane protocols are commonly used for neoadjuvant, adjuvant, and metastatic diseases, whereas platinum substances and etoposide are widely utilized for small-cell histology and high-proliferation tumors. At present, NEBC is categorized as an unspecified form of invasive breast carcinoma, lacking a more precise classification, as there is insufficient evidence to inform treatment decisions due to its low incidence and absence of randomized data. This review outlines the WHO classification, pathology, immunohistochemistry, diagnosis, treatment, and prognosis of NEBC. Furthermore, it encapsulates the most recent research on the molecular characteristics of NEBC, intending to offer innovative therapeutic insights into the disease.