CIRCULATing Biomarkers for Individualized Surgical Therapy in gastroEsophageal Cancer - Phase 1

This is an exploratory observational biomarker study in approximately 100 eligible patients with resectable adenocarcinomas of the esophagus and gastro- esophageal junction (GEJ) type I-II (GEAC) to investigate the difference deletion frequency of circulating tumor cells (CTCs) between peripheral veins and tumor-draining veins (primary endpoint), prognostic value, relevance of a set of two additional blood-based biomarkers analyzed from a single blood sampling tube (secondary endpoints). The underlying hypothesis is that the biomarker alone or in combination improve preoperative staging and help to identify patients at risk for metastasis. This should enable a better stratification of GEAC patients to neo-adjuvant treatment, (intensified) peri-operative treatment, or even surgery alone, in selected cases. The data of the CIRCULATE study shall be used design subsequent studies testing the predictive role of these biomarkers for surgical management. Patients will provide blood samples and lymphatic fluid during the operation and annual blood samples during clinical follow up of 5 years.