Young women with breast cancer have the same survival rates regardless of whether they have the BRCA gene mutation.
It’s good news for people with BRCA1 and BRCA2 mutations that raise their risk of cancer.
If they get cancer and have standard treatment, they live as long as breast cancer patients without the mutation.
Nearly 2700 women also found that a double mastectomy straight after being diagnosed with this type of breast cancer did not improve survival over 10 years.
However researchers said surgery could still be beneficial in the long term and they also said women with breast cancer can take time to decide.