P-257 in Vitro Drug Screening of Patient-Derived 3D Tumoroids Replicates Resistance to FOLFOX, FOLFIRI, and FOLFOXIRI in Clinically Resistant Patients with Metastatic Colorectal Cancer

International guidelines present three different chemotherapy regimens for first- and subsequent-line treatment of unresectable metastatic colorectal cancer (mCRC). The main doublet therapies used in first-line treatment is FOLFIRI (5-FU + irinotecan) and FOLFOX (5-FU + oxaliplatin). The two combination treatments offer a similar response rate of 34-55%. The treatments are therefore used indistinctly in the clinic. Evidence is however starting to appear showing that there are differences between the individual patients as to which of the combination treatments that are superior.