Metastatic primary breast neuroendocrine neoplasms: a case series

Intern Med J. 2023 Oct;53(10):1813-1818. doi: 10.1111/imj.15961. Epub 2022 Oct 31.

Abstract

Background: Breast neuroendocrine neoplasms represent a rare subtype of breast cancer which have not been well studied or characterised, particularly in the metastatic setting.

Aim: To present clinicopathological characteristics, treatment and outcomes of a series of patients with metastatic neuroendocrine carcinoma of the breast and review the current literature.

Methods: We performed a retrospective review to identify and describe patients with metastatic neuroendocrine carcinoma of the breast at our centre between 2011 and 2021. Medical records, pathology and imaging results were examined to evaluate the clinical and histopathological features as well as the treatment pathways and prognosis of these patients.

Results: We present a series of seven female patients with metastatic neuroendocrine carcinoma of the breast, as defined by the World Health Organization classification, over a period of 10 years (2011-2021) from a single centre. Median age at diagnosis was 48 years (range 39-63). Six of seven tissue samples expressed synaptophysin and chromogranin and were also oestrogen and progesterone receptor positive; median Ki-67 index was 50% (range 20-90%). All seven patients had demonstrated avidity on 18 F-FDG PET imaging, and the six who underwent 68 Ga-DOTATATE PET all had significant avidity. Treatment modalities and sequencing varied, but all patients received chemotherapy during their disease course. Six patients received three or more lines of treatment. Median overall survival was 31.8 months (range 3.7-108.6). Median progression-free survival (PFS) with first-line therapy for metastatic disease was 5.8 months (range 1.8-37.8).

Conclusions: This series shows the use of multiple modalities in treating this disease, with different sequencing in different patients. Despite multiple modalities used in the first-line setting, first-line PFS remains short. Larger series and further molecular characterisation are required to aid clinicians in managing this condition and to guide optimal treatment sequencing to improve outcomes in this rare patient group.

Keywords: breast carcinoma; breast neoplasms; cancer of the breast; malignant neoplasm; neuroendocrine tumour.

MeSH terms

  • Adult
  • Breast Neoplasms* / diagnostic imaging
  • Breast Neoplasms* / therapy
  • Carcinoma, Neuroendocrine* / diagnostic imaging
  • Carcinoma, Neuroendocrine* / therapy
  • Female
  • Fluorodeoxyglucose F18
  • Humans
  • Middle Aged
  • Neoplasms, Second Primary*
  • Neuroendocrine Tumors* / diagnostic imaging
  • Neuroendocrine Tumors* / therapy
  • Prognosis
  • Retrospective Studies

Substances

  • Fluorodeoxyglucose F18