Gastric Precancerous Condition

The goal of this study is to characterize and validate a signature of circulating biomarkers in plasma, associated with the presence of gastric preneoplasia in patients with preexisting gastric lesion compared with a control group. For this purpose: * Patients with pre-existing gastric lesions will be invited to participate to this study. If they are willing to participate an additional blood sample (9 mL) will be collected at the time of the blood collection performed during their routine care * Healthy subjects will be invited to participate to constitute the control group. If they are willing to participate a blood sample (9 ml) will be drawn specifically for this study