Epidemiological and survival outcomes of neuroendocrine carcinoma of the breast: a SEER data analysis.

Background: Neuroendocrine carcinoma of the breast (NECB) is a rare subtype of breast cancer, comprising only 0.1% to 5% of all breast cancer cases. Despite its rarity, it is important to gain a better understanding of the epidemiological, clinical, and prognostic features of NECB. The purpose of the study was to obtain population-based evaluations of the epidemiological and survival outcomes of NECB. Methods: The data of patients with neuroendocrine carcinoma diagnosed and enrolled between 2000 and 2017 were obtained from the Surveillance, Epidemiology, and End Results (SEER) database. Descriptive statistical analyses were used to assess the distribution and tumor-related characteristics of these patients. Kaplan-Meier curves and univariate and multivariate Cox proportional risk models were used to analyze variables that might be associated with prognosis. Results: This study included 7,856 patients with neuroendocrine carcinoma. The median age of the patients was 64 years, and most of them were female, White, and diagnosed at ≥60 years old. The most common pathological type was neoplasm. Survival analysis indicated that there were significant differences in age, marital status, registration location, American Joint Committee on Cancer (AJCC) stage, breast subtype, surgery of primary tumor, and no cancer cause surgery patients with NECB. The results also indicated that treatment with surgery, including surgery of primary tumor, surgery combined with radiation, and no cancer cause surgery, were all effective in improving the prognosis compared with not providing surgical treatment. Conclusions: In conclusion, NECB is a very rare lesion for which age, marital status, registration location, and surgery, AJCC stage, breast subtype were found to be independent prognostic factors.