A Delphic Consensus assessment: imaging and biomarkers in gastroenteropancreatic neuroendocrine tumour disease management

Abstract

The complexity of the clinical management of neuroendocrine neoplasia (NEN), is exacerbated by limitations in imaging modalities and a paucity of clinically useful biomarkers. Limitations in currently available imaging reflect difficulties in measuring an intrinsically indolent disease, resolution inadequacies, inter-/intra-facility device variability, and that RECIST (Response Evaluation Criteria in Solid Tumours) criteria are not optimal for NEN. Limitations of currently utilized biomarkers are that they are secretory biomarkers (chromogranin A, serotonin, neuron-specific enolase, pancreastatin), monoanalyte measurements, and lack sensitivity, specificity and predictive capacity. None meet NIH metrics for clinical usage. A multinational, multidisciplinary Delphi consensus meeting of NEN experts (n=33) assessed current imaging strategies as well as biomarkers in NEN management. Consensus (>75%) was achieved for 78% of 142 questions. The panel concluded that morphological imaging has diagnostic value. However, both imaging and current single-analyte biomarkers exhibit substantial limitations in measuring disease status and predicting therapeutic efficacy. RECIST remains sub-optimal as a metric. A critical unmet need is the development of a clinico-biological tool to provide enhanced information regarding precise disease status and treatment response. The group concluded that circulating mRNA was a more effective tool than current monoanalyte NEN biomarkers and clinical data were auspicious. It resolved that circulating multianalyte mRNA (NETest) had clinical utility in both diagnosis and monitoring disease status and therapeutic efficacy. Overall, it was concluded that a combination of tumour spatial and functional imaging with circulating transcripts (mRNA) would represent the future strategy for real-time monitoring of disease progress and therapeutic efficacy.