Rediscovering Biomarkers for the Diagnosis and Early Treatment Response in NEN (REBORN)

Neuroendocrine Neoplasm (NEN) are heterogeneous disease in terms of origin, localization and clinical presentation. Annual incidence of NEN is increasing in the last 30 years, even if the reasons underlying this rise have not been completely identified. Many biomarkers have been used in the diagnosis and follow-up of patients with NEN. In non-functioning NEN general tumor markers, such as chromogranin A (CgA) and neuron specific enolase (NSE), are commonly used but their sensibility and specificity are quite low. Recently, high-throughput tissue microarray and immunohistochemistry assessments have been performed to observe the expression pattern of new potential markers for NEN. In order to overcome limitations of tissue acquisition, the use of liquid biopsies has been advocated. It has been reported that tumor-educated platelets (TEPs) may easily enable blood-based cancer diagnostics. TEPs take up tumor-derived secreted membrane vesicles containing RNAs, of which circular RNAs (circRNAs) that can serve as a potential biomarker source for cancer diagnostics. This innovative approach in cancer detection has not yet been transferred to the NEN field. Flow cytometric analysis furnishes important insights into the immune status by providing information about the numbers and phenotypes of the immune cells, which are known to be altered in many types of neoplasms. In NEN, leukocytes subpopulations and peripheral blood mononuclear cells (PBMCs) are not been completely investigated but immunological alterations could represent a signal of neoplastic spread. Inflammatory and angiogenetic pathways' involvement in NEN behavior has recently received increasing attention. It is well known that NEN are known to be highly vascularized neoplasms and somatostatin analogues (SSA), used as first line drugs for most well differentiated NEN, can reduce tumour proliferation by various direct and indirect mechanism including the inhibition of angiogenesis. Tumor angiogenesis is a complicated process consisting of several steps, the angiogenesis cascade, regulated by endogenous and exogenous factors, including the system Angiopoietin-1 (Ang-1) and -2 (Ang-2) / Tie2 and Prokineticins. These systems are involved in neoplastic angiogenesis and inflammation in various types of cancer. Despite these evidences, the role of inflammatory and angiogenic factors in NEN detection and follow-up has not been completely clarified. The aim of the study is to evaluate immune profiling, angiogenetic markers and circularRNA sequencing in patients affected by locally advanced or metastatic pulmonary or GEP NENs and controls. Moreover, NENs patients will be evaluated also after 1 and 3 months of first line medical treatment.