Endocrine Abstracts

Pancreatic neuroendocrine tumours (pNET) in patients with MEN1 pose a particular and challenging clinical problem. Whilst patients with a pNET and clear clinical and biochemical evidence of hormonal hypersecretion are usually candidates for some form of surgical or medical therapy, the decision-making is far harder for those who are found to have a non-functioning tumour on surveillance imaging. There is a lack of knowledge of the differing biological behaviour between pNETs in MEN1 vs. sporadic disease, although some data suggest a more aggressive phenotype for MEN1. The clinical conundrum is that the main intervention, pancreatic surgery, carries significant morbidity and mortality, whilst there remains risk of metastatic disease and increased mortality for patients with known pNETs managed expectantly. Thus the risk-benefit ratio for any given individual is a fine decision needing MDT discussion and influenced by several factors including: size and position of tumour; general co-morbidities; risk of morbidity from intervention; and, importantly, patient preference. It is essential to take into account the experience that the patient has of outcomes for other members in the family who have been affected by MEN1, as this will have a key influence on their views. Sufficient consultation time is needed to explore these issues, to ensure a fully informed joint-decision making process. Survey data suggest that patients have insufficient information for this to be satisfactory. There are no long-term data for the use of somatostatin analogues in patients with MEN1 with non-functioning pNETs who are receptor-positive, but this may be a reasonable approach in some. For those with metastatic disease treatments may be based on current paradigms used for sporadic pNETs, and include the use of radionuclide therapy, and depending on the proliferation index or behaviour tyrosine kinase inhibitors, mTOR inhibitors and other parentral and oral chemotherapy, but MEN1-specific data are needed.