Local recurrences and distant metastases represent a major clinical challenge in the treatment of colorectal and pancreatic carcinoma (CRC; PDAC). The aim of this DKTK-wide research project was to introduce personalised strategies into the surgical treatment of GI-tumours by identifying pre-operative biomarkers for recurrence patterns. A comprehensive biobank of liquid and solid biopsies of patients with primary CRC (n=684) and PDAC (n=569) was established from April 2018 to August 2020 with joint efforts from all DKTK-sites by using matched standard operating protocols. Comprehensive clinical annotations and longitudinal sampling of these patients confer great value to the biobank for future translational and clinical research approaches aiming at identifying molecular biomarkers that predict the recurrence behaviour of GI tumours at an early stage.