490P Metastatic colorectal cancer derived organoids recapitulate genomic profile and treatment response of the original tumor

Development of a living organoid biobank derived from colorectal cancer patients: Towards personalized medicine

Abstract Background Organoids are 3D in vitroprimary culture of great interest for translational research representing an efficient and reproducible cancer model. The aim of this project is to generate a biobank of colorectal cancer (CRC) patients derived organoids (PDOs) that could be used to analyze molecular characteristics and to test different treatments as well as to study the underlying molecular causes of cancer and treatment resistance. Methods Primary or metastatic CRC tissues have been obtained from patients who underwent surgery. Tissue has been washed and incubated with antibiotics. After mechanical and enzymatic digestion, free cells have been seeded in Matrigel with proper me…

RAS mutations and cetuximab in locally advanced rectal cancer: Results of the EXPERT-C trial

Background: RAS mutations predict resistance to anti-epidermal growthfactor receptor (EGFR) monoclonal antibodies in metastatic colorectal cancer. We analysed RAS mutations in 30 non-metastatic rectal cancer patients treated with or without cetuximab within the 31 EXPERT-C trial. Methods: Ninety of 149 patients with tumours available for analysis were KRAS/BRAF wild-type, and randomly assigned to capecitabine plus oxaliplatin (CAPOX) followed by chemoradiotherapy, surgery and adjuvant CAPOX or the same regimen plus cetuximab (CAPOX-C). Of these, four had a mutation of NRAS exon 3, and 84 were retrospectively analysed for additional KRAS (exon 4) and NRAS (exons 2/4) mutations by using bi-di…