Liquid Micro-biopsy: a Novel Approach to Study Tumor Microenvironment From the Peripheral Blood

This is a prospective multicentre, tissue-based, non-profit study that includes two enrolling centres: Operating Unit (OU) No. 1 of Haematology and OU No. 2 of Medical Oncology, both at the IRCCS Azienda Ospedaliera-Universitaria di Bologna (AOUBO). Given the rarity of the pathology investigated and the lack of evidence from the literature, the study should be considered exploratory, aimed at providing provisional evidence and generating hypotheses that could be tested in future studies. The study involves the collection of peripheral blood samples from healthy volunteers (HD) matched for sex/age (n=30; Group 1) and patients with acute myeloid leukaemia at diagnosis (n=30; Group 2) at UO1 and patients with visceral sarcoma with measurable disease (n=30; Group 3) at UO2. Specifically, peripheral blood (equal to 60 mL) from healthy volunteers will be collected after obtaining the signed informed consent of the volunteers of the Associazione Onlus AIL Bologna ODV. From all participants in Groups 2 and 3, 60 mL of peripheral blood and 20 mL of bone marrow blood will be collected at routine clinical examinations. Bone biopsies (10 sections) will also be collected from Group 2 patients. All samples will be collected at the time of diagnosis (T0). All samples will be centralised at the Haematology Unit, IRCCS AOUBO and submitted for laboratory analysis. For patients with acute myeloid leukaemia, responses to treatment will be assessed on the basis of standard criteria according to the recommendations of the European LeukemiaNet of 2022 (Döhner H et al, Blood 2022). Clinical response for sarcoma patients according to the international RECIST imaging criteria assessed by routine computed tomography or magnetic resonance imaging scans.