Testing all women for the "Angelina Jolie gene", even if not considered at risk, would prevent cancers, save lives and is cost effective, say doctors.
The Hollywood actress had her breasts, ovaries and fallopian tubes removed due to the high risk of cancer in her case.
Women tend to be offered testing for the corrupted gene if cancer runs in the family.
However, the team at Queen Mary University of London says there are added benefits in testing everyone.
When women are diagnosed they can be monitored more closely for cancer and many, like Angelina Jolie, have preventive surgery.
Breast cancer survival 'unaffected by faulty gene'
The study, published in the Journal of the National Cancer Institute, estimated the impact of screening all 27 million women over 30 in the UK.
They said it would:
- prevent 64,500 more breast cancers
- prevent 17,500 more ovarian cancers
- save 12,300 more lives
The study also said mass screening would be cost-effective for the health service.
Dr Ranjit Manchanda, a consultant gynaecological oncologist and one of the researchers, told the BBC: "It [would] prevent many more cancers and save many more lives.
"But this is the first step in the process. We can't offer it immediately in the general population. We still need to understand how to deliver it."
Challenges include how to test so many people and how to offer genetic counselling to women affected.
BRCA
Mutations in the genes BRCA1 and BRCA2 can impair the body's ability to repair damage to DNA in its cells.
This can greatly increase the risk of developing cancers.
On average, women have a 2% chance of getting ovarian cancer in their lifetime.
But in those with BRCA mutations the chances can increase to between 10% and 60%.
Women have a 12.5% risk of getting breast cancer in their lifetime.
This goes up to between 45% and 90% with BRCA mutations.