Abstract
Objective
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.
Methods
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.
Results
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.
Conclusions
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.
Keywords
colorectal cancer - DNA mismatch repair deficiency - microsatellite instability -
immunotherapy - lynch syndrome
Bibliographical Record
Gustavo Sevá-Pereira, Claudio Saddy Rodrigues Coy, Carlos Augusto Real Martinez. Updates
on DNA Repair Gene Deficiency in Colorectal Cancer (dMMR). Journal of Coloproctology
2025; 45: s00451805009.
DOI: 10.1055/s-0045-1805009
