MEASUREMENT OF CIRCULATING MUTATION BURDEN

This study measures DNA fragments circulating in the blood to see if they can serve as an early warning sign for cancer in women who carry BRCA1 or BRCA2 gene mutations — which significantly raise the risk of breast and ovarian cancer. Researchers compare blood samples between sisters where one carries the mutation and one does not. **You may be eligible if...** - You are a woman between 30 and 50 years old - You are undergoing genetic cancer surveillance at the Centre François Baclesse - You are part of a pair of biological sisters where one has a BRCA1/2 mutation and the other does not - You are affiliated with social security **You may NOT be eligible if...** - You do not meet the sibling-pair requirement - You are outside the specified age range Talk to your doctor to see if this trial is right for you.