Treatment options for HER2-expressing colorectal cancer: updates and recent approvals

Colorectal cancer is a leading cause of cancer-related mortality worldwide. Approximately 3–5% of colorectal tumors harbor human epidermal growth factor receptor ( HER2) amplification which is associated with a higher incidence of intracranial metastasis and overall worse outcomes. In the setting of refractory metastatic RAS wild-type tumors, evidence supports the use of various HER2-blocking agents, including monoclonal antibodies, tyrosine kinase inhibitors, and novel antibody–drug conjugates. With a number of relatively active agents clinically available and even more in development, it is crucial for clinicians to familiarize themselves with the mechanisms of action, efficacy data, and safety profiles of these treatments. In this review, we aim to summarize key findings from past and ongoing trials with anti-HER2 agents in metastatic colorectal cancer.