Primary Large-Cell Neuroendocrine Carcinoma of the Breast Occurring in a Pre-Menopausal Woman

A high-quality model for predicting the prognosis of breast neuroendocrine carcinoma to help clinicians decide on appropriate treatment methods: A population-based analysis

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The incidence of breast neuroendocrine carcinoma (NEC) was approximately 1.96–2.37%.

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Breast NEC had poor prognosis than breast invasive ductal carcinoma (IDC).

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Patients with breast NEC may benefit from surgery plus chemotherapy.

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Efficient models were constructed to guide the treatment of breast NEC.

Background

Breast neuroendocrine carcinoma (NEC) is a rare malignancy with unclear treatment options and prognoses. This study aimed to construct a high-quality model to predict overall survival (OS) and breast cancer-specific survival (BCSS) and help clinicians choose appropriate breast NEC treatments.

Patients and methods

A total of 378 patients with breast NEC and 349,736 patients with breast invasive ductal carcinoma (IDC) were enrolled in the Surveillance, Epidemiology, and End Results (SEER) database between 2010 and 2018. Propensity score matching (PSM) was performed to balance the clinical baseline. Prognostic factors determined by multivariate Cox analysis were included in the nomogram. C-index and calibration curves were used to verify the performance of the nomogram.

Results

Nomograms were constructed for the breast NEC and breast IDC groups after PSM. The C–index of the nomograms ranged from 0.834 to 0.880 in the internal validation and 0.818–0.876 in the external validation, indicating that the nomogram had good discrimination. The risk stratification system showed that patients with breast NEC had worse prognoses than those with breast IDC in the low-risk and intermediate-risk groups but had a similar prognosis that those in the high-risk group. Moreover, patients with breast NEC may have a better prognosis when undergoing surgery plus chemotherapy than when undergoing surgery alone or chemotherapy alone.

Conclusions

We established nomograms with a risk stratification system to predict OS and BCSS in patients with breast NEC. This model could help clinicians evaluate prognosis and provide individualized treatment recommendations for patients with breast NEC.

Head to head: Do neuroendocrine tumours in the breast truly exist?

Breast cancer (BC) is a heterogeneous disease with a spectrum of morphological features. Concepts of histogenesis and differentiation in BC remain controversial. Recent evidence supports differentiation rather than histogenesis as the underlying mechanism for the myriad morphological appearances of BC. Prognosis and response to therapy are determined by a combination of factors including tumour grade, stage and receptor status whereas tumour histological types play an independent role in only limited examples. Neuroendocrine tumours (NETs) comprise one of the most debated entities in the breast since their first description. Apart from the rare small cell NE carcinoma (NEC) which has well-characterised features similar to their counterparts in other organs, the true existence, diagnostic criteria and clinical significance of NE neoplasms (NENs) in the breast are shrouded in controversy. At the core of this discussion is whether normal NE cells exist in the breast, and if breast NETs have distinct morphology and clinical behaviour. When NETs are encountered in the breast, metastatic origin has to be excluded. The more frequent situation in which NE differentiation is observed in breast cancers is in the context of recognisable, morphologically well described special type neoplasms like the hypercellular mucinous carcinoma and solid papillary carcinoma. In this review, arguments for and against maintaining the category of NENs in the breast are articulated in relation to existing literature on this group of unusual tumours.

Primary Neuroendocrine Neoplasms of the Breast: Still Open Issues

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.

Primary neuroendocrine carcinoma of the breast: a rare presentation and review of the literature

Primary neuroendocrine carcinoma of the breast (NEBC) is a very rare occurrence accounting for less than 0.1% of all breast cancers. Typically, the tumor presents with ER- and PgR-positive and HER-2-negative status. Despite its luminal type, NEBC is associated with a more aggressive clinical course and poorer prognosis compared to the other types of invasive breast cancer. Clinical and radiological findings are nonspecific. The most common clinical manifestation is a palpable mass whereas in mammography the tumor most commonly appears as a round or oval mass without spiculated margins. Herein, a very rare case of NEBC is described in an asymptomatic patient who presented with an area of architectural distortion and the presence of microcalcifications that was incidentally detected on a screening mammography. A review of the literature has also been conducted. The diagnosis of NEBC requires a thorough investigation to exclude the possibility of a metastatic neuroendocrine tumor from another site because the two entities require different treatment approaches. Due to the rarity of the disease, the optimal therapeutic approach has not been clearly defined. Surgical resection is the mainstay of treatment. Further research is needed to better understand the molecular characteristics of NEBC and identify novel targeted therapies.

Neuroendocrine breast carcinoma: a rare but challenging entity

Breast carcinoma with neuroendocrine differentiation, also known as neuroendocrine breast carcinoma (NEBC), includes a heterogeneous group of rare tumors, which account for 2–5% of all invasive breast carcinomas. Because of their low incidence, most of the current limited knowledge of these tumors derives from anecdotal case reports or small retrospective series. The diagnosis of NEBC is based on the presence of morphological features similar to gastrointestinal and lung NETs and neuroendocrine markers. NEBCs are usually hormone receptors positive and HER2 negative, but despite this luminal phenotype, most recent studies suggested that NEBC could be associated with worse prognosis compared to invasive breast cancer without neuroendocrine differentiation. Due to its rarity and lack of randomized data, there is little evidence to guide the choice of treatment, so NEBC is currently treated as any invasive breast carcinoma not-otherwise specified. Recently, attempts to molecularly characterize NEBC have been made, in order to provide new targets for a more personalized treatment of this uncommon entity.

[Primary large cell neuroendocrine carcinoma of the breast: a rare tumor in humans]

Le carcinome neuroendocrine à grandes cellules primitif du sein est une entité extrêmement rare. Moins de dix cas ont été rapportés dans la littérature. Nous présentons un nouveau cas survenu chez un homme de 61 ans qui s’est présenté pour une tumeur localement avancée du sein droit d’emblée métastatique aux poumons et à la plèvre, classée cT4bN1M1. Le patient avait reçu huit cycles de chimiothérapie à base de Docetaxel tous les 21 jours, avec une bonne réponse clinique et radiologique (>50%), puis mis sous hormonothérapie à base de tamoxifène avec une stabilisation pendant 18 mois. L’étude immuni-histochimique reste indispensable pour déterminer la nature neuroendocrine de cette tumeur. Le traitement n’est pas bien codifié vu la rareté de ce type de cancer.