Dutch people under the age of 25 with colon cancer form a small group within colon cancer patients (0.1% of the total number of colon cancer patients). Genetic studies of these patients and their tumors show that they are a unique group. Richarda de Voer, Marjolijn Ligtenberg, theme Tumours of the digestive tract, and colleagues published an article in Clinical Gastroenterology and Hepatology and argue that this group should be treated independently.
The study, funded by the Gastrointestinal Society (MLDS), began in 2013 by collecting data on - eventually - all 139 cases of colorectal cancer among young adults under 25 in the Netherlands between 2000-2017. Richarda de Voer and Marjolijn Ligtenberg, screened all of these people for this rare condition.
Often a genetic predisposition
By analyzing the DNA of the patients, a "genetic predisposition" was found in 39 percent of the cases. This means that the patients have an inherited predisposition to the development of the cancer. This percentage is much higher than usual, as it is less than five percent. Researcher Dr. De Voer: "It is important to know whether there is a genetic predisposition, because with predisposition there is often a chance of recurrence. Through regular checks we can detect a recurring or new colon cancer earlier. In addition, family members can also be tested. If it turns out that they are at increased risk, we can follow them."
Looking for the best treatment
Because tumors contain genetic mutations that do not occur in other body cells, the researchers also examined the genetic material of the patients' tumors. This showed that tumor-specific mutations also occur in different proportions among this subgroup than in older patients with colon cancer. Some of these changes may affect the patient's treatment. Marjolijn Ligtenberg: "We expect that a significant proportion of these young patients may benefit from immunotherapy. We therefore advocate genetic research in young patients with colorectal cancer, so that the best treatment can be found for them."