Genetic predisposition and cancer: new factors are identified

It is an unprecedented international study, in particular in terms of the number of participants: more than 10,000 women carrying BRCA1 or 2 mutations took part, including 1,600 from Unicancer’s GENEPSO cohort, in which Institut Curie played an important part.

The first finding was that the study, just published in the Journal of the American Medical Association (JAMA), indicates the risk of developing cancer according to the mutation. Thus 72% of the women carrying the BRCA1 mutation will develop breast cancer and 44% will develop ovarian cancer at 80 years of age. In women carrying the BRCA2 mutation, the risk is 69% and 17% respectively.

Another discovery is that the patient’s family history and the position of the mutation on the gene also influence the likelihood of one day developing cancer.“If a woman carrying a mutation has another woman in her family who has had breast cancer, her cancer risk is higher than that of a women with the same mutation but without a family history of breast cancer”, explains Nadine Andrieu, Inserm director of research and member of the genetics and cancer group of Unicancer, the federation of cancer research centers.

These discoveries should help follow-up of women carrying genetic mutations to be adapted and customized, integrated into the French monitoring and prevention recommendations.