Most of the women lived 10 years; 73 percent of the women with BRCA mutations lived 10 years and 70 percent of women without the mutations did.
"It can be hard for some patients to decide whether or not to have risk-reducing surgery, typically double mastectomies and removal of ovaries".
Researchers say the findings suggest there is no imperative for women with breast cancer who carry a BRCA mutation to opt for double mastectomies soon after their diagnosis.
Young women diagnosed with breast cancer who carry a BRCA mutation have the same chances of survival as women without the mutation after undergoing treatment.
But the study by the University of Southampton, of women between the ages of 18 and 40 years, found after treatment, there was no significant difference is survival rate between women who have a faulty gene and women who do not.
Martin Ledwick, Cancer Research UK's Head Information Nurse, said: "Although BRCA faults increase the risk of young women developing cancer, their outlook once diagnosed is no worse than that for young women with breast cancer who don't carry the BRCA gene faults".
What is the BRCA gene?
BRCA1 - Led Angelina Jolie to have a double mastectomy because of her risk of breast cancer.
Mutations in these genes stop DNA repairing itself and increase the risk of cancer developing.
Angelina Jolie had a preventative mastectomy, before she developed cancer.
"This important topic needs more prospective research as preventive surgical measures might have an effect on what might be a very long life after a diagnosis of breast cancer at a young age", wrote Peter Fasching, MD, of Friedrich-Alexander University Erlangen-Nuremberg, Germany, in an editorial published with the study. It means that they can take time to discuss whether radical breast surgery is the right choice for them as part of a longer-term risk-reducing strategy.
'Decisions about timing of additional surgery to reduce future cancer risks should take into account patient prognosis after their first cancer, and their personal preferences'.
Katherine Woods, from charity Breast Cancer Now said the findings "could enable many patients to make even more informed choices regarding their treatment". Olaparib was first approved in 2014 for ovarian cancer and has now received approval to treat patients with germline BRCA-mutated, human epidermal growth factor receptor 2 (HER2)-negative metastatic breast cancer who were previously administered chemotherapy, according to the FDA.