Diagnosis of Neuroendocrine Neoplasms and Assessment of Response to Surgery by Means of Measurement of Gene Transcripts in Blood

Biomarker-based tools that can accurately predict gastroenteropancreatic neuroendocrine tumor (GEP-NET) treatment response and tumor recurrence are currently not available. Circulating biomarkers that are associated with GEP-NETs are limited to measurements of plasma chromogranin A (CgA). The investigators have developed a PCR-based tool to quantitate (score) the circulating GEP-NET molecular signature ("liquid" biopsy) with high sensitivity and specificity. This signature can identify all types of GEP-NETs including small (1cm) non-metastatic tumors, is significantly reduced after tumor debulking and is decreased following surgical "cure". Elevated post-surgical scores are associated with tumor recurrence within 6 months in ~40% of cases. Current NET treatment protocols are associated with tumor recurrence (progression free survival) ranging from 5-18 months. The majority of patients will experience a relapse within 18 months irrespective of the treatment approach. The investigators hypothesize that a PCR measurement of circulating NET mRNA can accurately predict the extent of surgical resection (tumor removal) and elevated scores can predict tumor relapse before this occurs. This biomarker protocol seeks to test this hypothesis and evaluate whether changes in plasma CgA are as effective in predicting resection and recurrence.