Breakthrough in the detection of hereditary colorectal cancer

Thanks to Radboudumc’s research, a new DNA analysis technique can be used to demonstrate that a group of patients have an inherited form of colon cancer. Until now, this could not be demonstrated with a conventional DNA analysis. For affected patients, it means that making the correct diagnosis improves patient treatment and monitoring. Furthermore, thanks to this DNA analysis, it is now also possible to specifically test their family members if they have an increased risk of contracting this form of cancer.

Lynch-like syndrome

When colon cancer is diagnosed, it is often Lynch syndrome, which is caused by abnormalities in four genes in the DNA. Demonstrable deviations with common analysis techniques. “However, we don’t find those DNA abnormalities in a small group of patients, even if they are young and have relatives with the same form of cancer. So these patients appear to have Lynch syndrome, but we couldn’t make the diagnosis. We call this Lynch-like syndrome,” says research leader Richarda de Voer of the Department of Genetics at Radboud University Medical Center.

Years of waiting for colon cancer diagnosis

For the heck of it Research became the new one for 32 patients with Lynch-like syndrome
Applied DNA analysis technique. It is the first time that this technique, which analyzes DNA much more precisely, has been used to detect a rare hereditary cancer.

“We are using it to study long pieces of DNA, whereas in the past we could only measure small fragments,” continues De Voer. “’This way we can map parts of the DNA that we weren’t able to look at before. With this technique we found new abnormalities in two of the four genes involved in Lynch syndrome in six patients. Some patients have been waiting eighteen years for a diagnosis, which we can now give them. They have Lynch syndrome.

Better patient care

With the accurate diagnosis of Lynch syndrome, it is now possible to ensure that the care of these patients can be significantly improved. It means that after this diagnosis they can be helped with specific treatments that are very effective in this form of cancer, such as immunotherapy.

Additionally, patients with Lynch syndrome also have an increased risk of other forms of cancer. In women, this mainly concerns uterine cancer. De Voer: “Because we now know what the patient has, we check him much more often and in a more targeted way.”

For doctors, this means they can better inform the patient’s relatives about possible risks and test for these new DNA abnormalities. Uncertainty about these kinds of illnesses goes a long way for people. Developments can remove much of this uncertainty and unnecessary checks can also be prevented or whether it is useful to carry out more frequent checks when talking about increased risk. De Voer foresees broader applicability of this new DNA analysis, which would make it possible to detect many other unexplained hereditary cancers at an early stage.