Researchers Identify Potential Colorectal Cancer Triggers

As a medical oncologist at Morrison Cancer Center in Hastings, Nebraska, Dr. Sanda Morar draws on the most up-to-date information in her field. Dr. Sandra Morar focuses particularly on treating gynecological, breast, and colorectal cancers.

According to research recently published by the journal Immunity, the loss of two specific genes may increase a patient's risk of colorectal cancer. The genes in question play a role in encoding two kinase proteins, the loss of which can prompt the development of noncancerous or precancerous growths known as serrated polyps. Prior research has shown that as many as 35 percent of colorectal cancers develop from this type of polyp.

Through a mouse model, researchers found that the loss of these genes caused the infiltration of the PD-L1 protein, which helps cancer cells to survive in the body. Introduction of a TGF-beta receptor inhibitor and anti-PD-L1 reduced the size of the tumors.

Researchers believe that these findings may also help to explain the increased risk of colon cancer in patients with inflammatory bowel disease, or IBD. The study showed that gene loss decreased the concentration of CD8+ immune cells and prompted the development of colorectal cancer. The loss of these immune cells can be opportunistic for colorectal cancers, particularly since patients with IBD may already be immunocompromised due to immune-suppressing treatments.