Patients at high risk of colorectal cancer can be identified through gene mutation

Reported by Susan Aldridge, PhD, medical journalist

A new prediction model will help doctors decide whether a patient has a high risk of carrying a gene mutation that predisposes to colorectal cancer.
Prediction models have already been developed for hereditary breast-ovarian cancer based upon BRCA1 and BRCA2 gene mutations. Now researchers at the Dana-Farber Cancer Institute report upon a similar approach among patients with Lynch syndrome, also known as hereditary nonpolyposis colorectal cancer. This is the most common form of hereditary colorectal cancer, accounting for two to five per cent of cases. Lynch syndrome is caused by mutations in the MLH1 and MSH2 genes.

In the development of the model, data from nearly 2,000 individuals having gene mutation testing was gathered. Medical and family history factors were used to predict with likelihood of gene mutations. A model was developed in 898 individuals and then validated in 1,016 patients. Overall, 14.5 per cent of the first group had gene mutations and 15.3 per cent in the second group. The model should prove useful in guiding the clinical evaluation of individuals potentially at high risk of developing colorectal cancer, the researchers say.

Source
Journal of the American Medical Association 27th September 2006 Volume 296 pages 1469-1478