NEUROENDOCRINE CARCINOMA OF THE BREAST: 18 CASES WITH LONG-TERM FOLLOW-UP

Abstract

Objective: Primary neuroendocrine carcinoma of the breast (NECB) is a rare distinct type of breast carcinoma. There is limited data about the optimal management, treatment, and prognosis. Therefore, we analyzed the clinicopathological features, management and the clinical outcome of this rare breast carcinoma. Material and Methods: Patients diagnosed as NECB between July 2008 and January 2018 were included in the study. Medical records were retrospectively reviewed. Results: A total of 4,896 breast cancer patients were reviewed and 18 NECB (0.4% of all cases) were extracted. The median age was 61.5 (30-82). Thirteen cases (72.2%) underwent breast conserving surgery. Eight patients had axillary lymph dissection. All of the cases were pathological T1 and T2. Only one patient was pathological stage 3. Median tumor size was 20.5mm (10-45). Only two cases presented with small cell subtype, the rest were well-differentiated. Hormone receptor was positive and HER2/neu was negative for all cases. Of the 15 patients with known Ki-67, three had high expressions (≥20%). No local or distant disease recurrences and death related with NECB were detected at a median follow-up period of 101 months (33-148). Conclusion: NECB is more likely to be hormone receptor positive and HER2/neu negative as luminal A or B subtype. An excellent clinical outcome is remarkable despite a substantial number of patients with axillary lymph node positivity specifically for well-differentiated subtype. Less invasive treatment options should be kept in mind.