Definition of a Multiparametric Prognostic and Predictive System of Classification of NET G3 Patients: an observAtional, Prospective Analysis of the Correlation Between Functional Imaging and Clinical Outcome (TAPIOCA)
The 2017 World Health Organization (WHO) introduced a new category of high-grade, well-differentiated neuroendocrine neoplasms (NENs) that called neuroendocrine tumors (NETs) G3 in pancreatic NENs classification and, then, in 2019, for all gastro-entero-pancreatic (GEP) tract NENs. The new classification made it possible to separate NETs G3 from high-grade, poorly-differentiated, NENs that are called neuroendocrine carcinomas (NECs). However, in clinical practice, we observed that several clinical, pathological and radiological differences are arising among NET G3 patients, suggesting that a multiparametric definition of NET G3 is needed.
• Histological diagnosis of well-differentiated neuroendocrine tumor G3 performed or reviewed by a NEN-dedicated pathologist. In case of late-NET G3 (see Patients and Methods), a NEN-dedicated pathologist will perform a pathologic review of the previous NET G1/2, too, unless a NEN-dedicated pathologist has already done and except for diagnoses performed in a NEN-referral Center.
• Age \> 18 years
• Signed written informed consent
• Available tumor tissue (formalin-fixed paraffin-embedded, FFPE) (preferably within 6 months). If the tumor contained in FFPE tissue block cannot be provided in total, sections from this block should be provided that are freshly cut. Preferably, 25 slides should be provided (minimum of 15 slides). If tumor tissue is not available, patients should be willing to undergone to a new biopsy.
• late-NET G3 patients that will come to our Institute at the moment of NET G3 diagnosis will be enrolled only if they performed 68 Gallium-DOTATOC positron emission tomography (PET)/CT and 18 fluorodeoxyglucose (FDG)-PET/CT for the previous NET G1/2. The previous functional imaging performed during the NET G1/2 history shall be available for the review by our specialist in nuclear medicine.