Introduction BSG guidelines advise that, in patients presenting with symptoms suspicious of gastroenteropancreactic neuroendocrine tumour (NET), baseline gut hormone (GH) tests should include Chromogranin A (CgA) and urinary 5HIAA. Other specific biochemistry should be requested depending on the syndrome suspected. We reviewed the use of gut hormone screening in a North East England Trust and examined the association between positive results and NET diagnosis.

Methods We reviewed all GH screens requested between July 2012 and June 2013. The following data were collected: specialty of requesting physician, indication, results and clinical outcome. We compared results of GH screens (CgA and then other GHs) with the diagnosis of NET to calculate specificity. Finally, we looked at all NET diagnosed in the trust over the same period, reviewing GH levels in those tested following diagnosis,in order to calculate sensitivity. Financial implications of different GH testing strategies were assessed using these results.

Results Of a total 51 requests for gut hormone screens, 21 were made by gastroenterologists and 8 by surgeons. 19 requests in total were made for investigation of diarrhoea, 12 for upper GI symptoms/peptic ulcers, 5 following positive histology or lesions on imaging and 15 for other symptoms. A total of 459 GH were tested at a cost of £315 per patient. 32/51 patients had normal CgA levels, none of which went on to be diagnosed with NET. 19 had a raised CgA of which 2 were already known to have NET but no new NET were found (specificity 65.31%). Patients with diarrhoea had a particularly high false positive rate (7/19=37%). Of 18 patients newly diagnosed with NETs in the trust, 5 had GHs tested (all following diagnosis)-3/5 had raised CgA (cost £44 per patient),a sensitivity of 60% (this increased to 80% when combined with u5HIAA testing). Measuring other gut hormones only marginally increased sensitivity but greatly reduced specificity of the screening.

Conclusion Gut hormone screening was not being performed in line with BSG recommendations in our Trust, leading to excessive numbers of tests being performed with low sensitivity and specificity. We worked with the trust biochemistry department to clarify the indications for GH testing and rationalise the screening test performed. We now offer an ‘endocrine diarrhoea screen’ of CgA and u5HIAA. Other hormones are measured only if a specific syndrome is suspected/in patients with known history/family history of NET, representing a cost saving of £271 per patient. It is envisaged that this change in practice will save the trust at least £12,000 per annum whilst improving clinicians` decision making around testing for NET.

Disclosure of Interest None Declared.