March 18, 2025- A discovery by Mayo Clinic researchers may help explain why immunotherapy hasn’t been helpful for many patients with metastatic colorectal cancer. In findings published in Clinical Cancer Research, the team identified specific proteins — fibronectin and smooth muscle actin — within colorectal cancer tissues that are associated with resistance to immunotherapy treatment. Immunotherapy is a major advance in treating cancer, but many patients, including those with metastatic colorectal cancer, do not respond to it.
The researchers focused on 10 regions at the invasive margin of a tumor. They applied digital spatial profiling to investigate 71 distinct proteins in both the tumor’s epithelial compartment and the surrounding stromal compartment. The evidence, they say, suggests that these proteins can contribute to suppression of the anti-tumor immune response.