Radboud researchers: New form of colon cancer discovered

Researchers from Radboud University Medical Center have discovered a new gene that causes hereditary colon cancer. This gene only causes an increased risk of colon cancer if both parents have it, which means that the siblings of a patient suffering from this form of cancer have an increased risk of also getting it, but not the patient's children. Colon cancer runs in the family in about 35 percent of patients suffering from this disease. The gene causing the hereditary colon cancer is known in 10 percent of the cases, which means that doctors can pinpoint exactly which family members are at high risk. This also means that the gene causing the cancer in the other 25 percent is not known yet. According to Nicoline Hoogerbrugge, professor of hereditary cancer, finding new genes is very important, but is also becoming increasingly difficult. Many groups worldwide have bee searching for new genes for hereditary colon cancer over the past two years, often in large groups of patients and mostly with disappointing results, according to Roland Kuiper of the Genetics department. "We approached it differently. Of 51 well selected patients, we mapped all the genes and looked at similar mistakes in their DNA. We eventually found flaws (mutations) in the NTHL1 gene in three families with multiple patients." To get this newly discovered form of hereditary colon cancer, a person must get the mutated NTHL1 gene from both his mother and his father. "That means that children of patients have no increased risk of this hereditary form of cancer. Because the chances are very small that the partner of their father or mother also have such a defective gene. In fact, with this form of hereditary cancer, we only have to examine the siblings of the patient for the same deviation." said Hoogerbrugge. The discovery of this new gene has great advantages for the diagnosis of a patient's siblings, as they can be tested in a timely manner and receive the necessary treatment. Hoogebrugge is pleased with the discovery. "Now we can detect even more families that are at risk of hereditary colon cancer. Family members can then let us figure out exactly whether or not they are at an increased risk. Those with an increased risk, can then with the proper precautions prevent getting colon cancer. That's pure profit."