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.
Keywords: BRAF; EGFR; RAS; VEGF; mCRC; primary tumor location; tumor sidedness.
Lay abstract Each patient’s cancer is unique. For example, colon cancer on the left side is different from colon cancer on the right side. Colon cancer is different from cancer of the rectum. Cancers also have changes in their genes, which means some treatments should work, while others may not. Doctors can select among different medicines to find the drug that works best for each patient. We looked at patients with cancer of the colon or rectum that has spread to other organs. We tried to find out how doctors in Europe select drugs for their patients after performing tests called RAS or BRAF. We found that doctors make different choices in different countries.