Phase IV, national, multicenter, open, multi-cohort interventional study:~Regorafenib - mCRC, GIST, and HCC = 3x30 = 90 patients~Everolimus - gepNET = 60 patients~Sunitinib - pNET and GIST = 60 patients~Cabozantinib - HCC = 60 patients~Encorafenib-cetuximab - mCRC = 60 patients~The patients included will be treated and followed according to standard practice (national recommendations and according to the summary of product characteristics (SmPC) of each molecule). According to the cohort, a maximum of 1 to 2 blood tubes will be taken at different times during the study: at baseline, then 1 month after the start of treatment, then 2 months after the start of treatment, if an adverse event of specific interest (AESI) occurs, and in case of progressive disease.
Targeted therapy drug monitoring in digestive oncology: Dosage of plasma levels of various multikinase inhibitors (MKI) in patients treated for advanced digestive cancer (gastrointestinal stromal tumor (GIST), metastatic colorectal cancer (mCRC), hepatocellular carcinoma (HCC), gastroenteropancreatic neuroendocrine tumor (gepNET), or pancreatic neuroendocrine tumor (pNET)), with the aim of determine the optimal dose adapted for each patient, in the future.