Breast cancer: Discovery of increased risk from CHEK2 heralds testing breakthrough
A genetic link that could double the risk of some women developing breast cancer has been discovered by scientists at Cancer Research UK.
Doctors are now determining whether women who have a strong family history of breast cancer should be offered genetic testing to identify whether they have inherited the wrong version of the gene, called CHEK2. Women who test positive have been found to have twice the risk of developing the disease. The findings follow the identification in the mid-1990s of high risk genes BRCA1 and BRCA2.
"Women with a strong family history of breast cancer can already receive genetic tests for the BRCA genes. The next step will be to evaluate whether testing for CHEK2 is useful in the clinic. At the moment it is not clear what contexts CHEK2 testing would be appropriate," said lead researcher, Professor Doug Easton.
During the study, 10,860 women with breast cancer and 9,065 healthy women were tested. The faulty version of the gene was found to be more common in women diagnosed with breast cancer than in healthy women. From these findings, scientists calculated that having the variant of the gene actually doubles the breast cancer risk, regardless of family history. The risk was also found to be higher among younger women with the gene.
The faulty gene is described in the report as a missing vital piece, like 'the brake pedal in the car.' This means that carrying the version of the gene increases the likelihood of other genes evading the body's repair processes and replicating themselves, which could then lead to a tumour.
"As we identify more genes that impact on hereditary breast cancer, we move closer to a comprehensive genetic test to accurately assess the risk of inheriting the disease," said Professor Easton.
Director of clinical and external affairs at Cancer Research UK, Professor Robert Souhami, said identifying the gene's impact was a breakthrough: "This puts us in a much better position to tackle breast cancer, both through testing high risk groups and eventually through new clinical strategies."
