Updates on DNA Repair Gene Deficiency in Colorectal Cancer (dMMR)

Abstract

This study explores the role of DNA mismatch repair (MMR) deficiency (dMMR) in colorectal cancer (CRC). We review how it influences the development of cancer, how it is diagnosed, and the latest treatments available, including how patients with dMMR respond to specific therapies differently than others.

We conducted a thorough review of current research, focusing on studies that address how dMMR affects people with colorectal cancer. We excluded studies on animals or cases that weren't directly relevant to human colorectal cancer. The focus was on how new knowledge and treatments change patient care.

Around 15% of colorectal cancer cases involve dMMR, which is often linked to Lynch Syndrome and specific genetic changes. Patients with dMMR tend to have better outcomes in the early stages of cancer but respond poorly to traditional chemotherapy. However, these patients show significant improvement with immunotherapy, especially treatments targeting immune checkpoint proteins. Advances in diagnostic tools like microsatellite instability (MSI) testing and next-generation sequencing are helping doctors identify these cases earlier and choose better treatment options.

Recognizing dMMR in colorectal cancer is crucial for deciding the best treatment plan. Immunotherapy is proving to be particularly effective for these patients, and as diagnostic methods improve, we expect even better outcomes, especially for those with a hereditary risk like Lynch Syndrome.