Special Issues
There have been significant improvements in the survival of patients with metastatic colorectal cancer (mCRC) over the past decade. However, patients with the disease who fail to respond to first- or second-line therapies, including chemotherapy and monoclonal antibodies, have few treatment options. Advances in subsequent treatment lines rather than in first- or second-line therapies now drive improvements in survival for these patients.
PD-L1 expression is a rational biomarker to predict response to PD-1/PD-L1 ICI therapy, and has been studied extensively in clinical trials. A recurring theme emerging from available clinical data is that high levels of tumor cell membrane PD-L1 expression correlate with better outcomes with PD-1/PD-L1 blockade.