Neuro-endocrine tumours

Tumours derived from neuro-endocrine or chromaffin cells. These may occur in isolation or as part of MEN1 or neurofibromatosis. The diagnosis carcinoid syndrome refers to the association of diarrhoea and flushing associated with peptide secretion from these tumours.

Assessment at diagnosis

All patients in whom a histological or biochemical diagnosis of a NET has been made require a full assessment.

This should include fasting gut hormones and 2x24hr collections for 5HIAA in all cases. Baseline imaging should include cross sectional imaging CT or MRI of the chest, abdomen and pelvis, octreotide and MIBG scans, and further bowel imaging with endoscopy and barium imaging if indicated.

Refer to multidisciplinary meeting

All treatment options and follow up arrangements should be considered by a multidisciplinary team.

Treatment should be started with somatostatin analogues

Typical doses would be 600mg of subcutaneous octreotide daily in divided doses, which may immediately control the symptoms of diarrhoea and flushing.

A depot somatostatin analogue should then be started. This may not control symptoms immediately, so it is standard practise to continue octreotide for the first seven to ten days.

Consider surgery

Where local symptoms are prominent, for example with sub acute bowel obstruction, surgery may be very effective.

Tumour debulking may also be attempted depending on the site, size and stage of the disease.

Meta-iodobenzylguianidine therapy

MIBG treatment may be highly effective at controlling metastatic disease in those with positive uptake scans.

Octreotide therapy

This may also be effective in patients with positive uptake scans, though is less widely available than MIBG treatment.

Hepatic artery embolisation

This may be appropriate for large and symptomatic hepatic metastases.

Chemotherapy

Streptozocin and 5 flurouracil containing chemotherapy regimes may be highly effective for metastatic disease.

Medical therapies for symptom control


Somatostatin analogues

These may reduce peptide hormone release dramatically and so improve diarrhoea, flushing and other symptoms.


Steroids

Hypoglycaemia of insulinomas may respond at least transiently to oral steriods.


Diazoxide

This treatment is effective for hypoglycaemia but may cause oedema, hypertrichosis and hypokalaemia.