PD-1/PD-L1 immune checkpoint blockade-based combinational treatment: Immunotherapeutic amplification strategies against colorectal cancer

Colorectal cancer (CRC) is one of the most common malignant tumours of the digestive system, and most patients are already in an advanced stage at the time of diagnosis. Moreover, current single-use immune checkpoint inhibitors (ICIs), such as programmed cell death-1 (PD-1) and programmed cell death-ligand 1 (PD-L1) inhibitors, are only effective for some advanced CRC patients with microsatellite instability-high (MSI-H), and most patients may...