Invasive neuroendocrine carcinoma of the breast: a population-based study from the surveillance, epidemiology and end results (SEER) database

Abstract

BackgroundNeuroendocrine carcinoma (NEC) of the breast is a rare type of carcinoma that has not been well studied or characterized. Of the limited number of studies reported in the literature, most are case reports. A few small retrospective series studies have been reported.MethodsWe reviewed data on 142 cases of mammary NEC recorded in the surveillance, epidemiology, and end results (SEER) database during 2003–2009 and evaluated disease incidence and patient age, sex, and race/ethnicity; clinicopathologic characteristics; and survival in comparison to invasive mammary carcinoma, not otherwise specified. We also performed univariate and multivariate analyses to identify prognostic factors in this disease.ResultsReview of the 142 SEER cases revealed that NEC is an aggressive variant of invasive mammary carcinoma. It generally occurred in older women (>60 years); present with larger tumor size (>20 mm), higher histologic grade, and higher clinical stage; and result in shorter overall survival and disease-specific survival than invasive mammary carcinoma, not otherwise specified (IMC-NOS). Overall survival and disease-specific survival were shorter in NEC at each stage than in IMC-NOS of the same stage. Furthermore, when all NEC and IMC-NOS cases were pooled together, neuroendocrine differentiation itself was an adverse prognostic factor independent of other known prognostic factors, including age, tumor size, nodal status, histologic grade, estrogen/progesterone receptor status, and therapy.ConclusionsNEC is a rare but aggressive type of mammary carcinoma. Novel therapeutic approaches should be explored for this uniquely clinical entity.

Clinicopathological Study of Neuroendocrine Carcinoma of the Breast

“…NECs of the breast are usually seen in mature women, around the seventh or eighth decade of life, and the tumors tend to be larger (measuring ≥20 mm in diameter), higher grade, and more advanced than usual breast cancers. Studies have found both progression free survival and overall survival to be shorter than those of patients with usual IDC [7] [8]. However, in the present study, the patients with NEC had survival rates similar to those of patients with usual IDC and had favorable outcomes (MST of 75 months).…”

Neuroendocrine Carcinoma of the Breast: Current Evidence and Future Perspectives

“…Sporadically, NECB may lead to clinical conditions related to hormonal hypersecretion, because of ectopic production of adrenocorticotropic hormone [20], norepinephrine [21], or calcitonin [22]. The disease is more commonly diagnosed in elderly women in their sixth or seventh decade of life [3]. Only a few cases of NECB have been reported in males [3,23,24].…”

“…The disease is more commonly diagnosed in elderly women in their sixth or seventh decade of life [3]. Only a few cases of NECB have been reported in males [3,23,24].…”

“…The prognostic relevance of neuroendocrine differentiation in breast carcinoma is still debated because several studies have been published with mixed results [3,6,[31][32][33][34][35]. These conflicting results might be explained by the limited number of cases reported in each series, by the different inclusion criteria based on whether the 2003 or 2012 WHO definitions were applied to identify NECB, and also by the analysis performed considering NECB as a whole, without analyzing the outcomes according to the different histologic subtypes.…”

“…Their incidence has been reported to range from less than 1%-5% of breast cancers [2,3], according to the different series and the different diagnostic criteria. However, some authors reported a neuroendocrine differentiation in up to 20% of breast carcinomas [4].…”