Impact of biomarkers and primary tumor location on the metastatic colorectal cancer first-line treatment landscape in five European countries.

Background: Advances in therapies for patients with metastatic colorectal cancer (mCRC) and improved understanding of prognostic and predictive factors have impacted treatment decisions. Materials & methods: This study used a large oncology database to investigate patterns of monoclonal antibody (mAb) plus chemotherapy treatment in France, Germany, Italy, Spain and the UK in mCRC patients treated in first line in 2018. Results: Anti-EGFR mAbs were most often administered to patients with RAS wild-type mCRC and those with left-sided tumors, while anti-VEGF mAbs were preferred in RAS mutant and right-sided tumors. Adopted treatment strategies differed between countries, largely due to reimbursement. Conclusion: Biomarker status and primary tumor location steered treatment decisions in first line. Adopted treatment strategies differed between participating countries.