Primary Neuroendocrine Neoplasms of the Breast: Still Open Issues.

Marco Gallo,Annamaria Anita Livia Colao,Rosaria Maddalena Ruggeri,Severo Campione,Erika Messina,Antongiulio Faggiano,Valentina Di Vito,Nicoletta Fortunati,Fabio Lo Calzo

doi:10.3389/fendo.2020.610230

Abstract

Neuroendocrine breast tumors represent a rare subtype of breast cancer, accounting for less than 1% of all neuroendocrine neoplasms. Starting from their pathology definition, and going through their prevalence, prognosis and treatment, our knowledge is still really uncertain. In the present short review of the medical literature on this topic, we have evaluated in details their epidemiology, risk factors, pathogenesis, pathology, clinical presentation, radiographic aspects, prognosis, and therapy. We have thus been able to identify a number of open issues regarding primary neuroendocrine neoplasms of the breast that need to be clarified. Our ultimate aim was actually to try to understand whether neuroendocrine neoplasms of the breast can be considered a definite clinical entity and if neuroendocrine differentiation of breast tumors has a really clinical relevance.

Highlights

Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors deriving from neuroendocrine cells
These results are suggestive of a better prognosis of invasive breast cancer with neuroendocrine features compared to their non-neuroendocrine counterparts (48). These data were confirmed in a prospective observational study performed on a cohort of 35 patients with BNEN reporting a lower recurrence rate in breast cancers with an expression of neuroendocrine markers >50% compared to those with focal expression (49). These findings provide a stratification based on neuroendocrine markers expression and may be helpful for detecting better treatment strategies, since all invasive breast carcinomas are currently treated according to non-endocrine tumor components guidelines
Albeit BNEN were firstly described more than 40 years ago, and have been categorized more and more precisely thereafter, its rarity, together with still persisting diagnostic uncertainties, hampers drawing a precise clinical and prognostic picture

Summary

Introduction

Neuroendocrine neoplasms (NENs) are a group of heterogeneous tumors deriving from neuroendocrine cells. There are neither specific clinical signs for this tumor nor differences in the clinical features of primary BNEN compared to other types of breast cancer. Lai et al showed that in a sample of 224 patients with NENs, breast carcinomas expressing high levels of neuroendocrine markers and cytomorphologic features were characterized by a better prognosis.

Results

Conclusion