Background: Neuroendocrine tumours (NETs) are a heterogenous group of malignancies that frequently metastasise to other organs. Both breast cancer and NETs have a predilection for liver, lymphatic and bone metastases. We report the investigations and management of a patient with concurrent small bowel NET and breast cancer.
Case: 66 year-old female. Presented with 2 years of abdominal pain, diarrhea and flushing. Octreotide scintigraphy and biochemical investigations diagnosed metastatic small bowel NET with carcinoid syndrome. After 1 year somatostatin analogue therapy, surveillance imaging showed evidence of disease progression. Pre-Lutathera biopsy: Ki-67 1-2 %, Grade 1 NET. Underwent small bowel resection and anastomoses following obstruction. Surgical histology: Ki-67 4-5 %, Grade 2 NET. Three years following NET diagnosis, the patient-identified a breast lump. Triple assessment: Grade 1 invasive tubular carcinoma, ER 8/8, HER2 negative. Subsequently underwent wide local excision, sentinel lymph node biopsy and hormonal treatment. Subsequent NET surveillance imaging: Enlarging liver metastases while stable disease elsewhere. Biopsy of liver metastases: Ki-67 10 %, Grade 2 NET. Excludes metastatic breast cancer. MDT advised liver metastasectomy in view of oligoprogression.
Discussion points: (1) Treatment strategy was dependent upon correct metastases characterisation. (2) Successive biopsies showed increasingly aggressive NET features across 5 years. (3) Surgery can be an appropriate option, especially if one lesion is behaving more aggressively.