The scientists created a method to predict a woman's risk of breast cancer by combining information on family history and genetics with factors such as weight, age at menopause, alcohol consumption, and use of hormone replacement therapy.
It is said to be the most comprehensive method so far to predict the risk of breast cancer in women, according to a study by Cancer Research UK published in Genetics in Medicine taking into account more than 300 genetic indicators.
Although some of the factors have a small impact on the likelihood of developing the disease, the researchers found that by considering all of them at one time, they can identify groups of women who have different risks of developing breast cancer.
Researchers have created an online calculator for GPs to use in their surgeries and is being tested before being considered for wider use. Doctors are encouraged to respond as a series of online questions about their patient, including their medical and family history, if they have any known genetic changes linked to cancer, their weight and whether they drink alcohol.
Professor Antonis Antoniou, lead author of the University of Cambridge, said: "This is the first time anyone combines so many elements in a breast cancer prediction tool. It could be a watershed for breast cancer because we can now identify a large number of women with different levels of risk – not just women who are at high risk.
"This should help doctors tailor the care they deliver, depending on the risk level of their patients. For example, some women may need additional consultations with their physician to discuss screening or prevention options, and others may just need advice on their lifestyle and diet.
"We hope this means more people can be diagnosed early and survive the disease longer, but more research and testing is needed before we fully understand how this could be used."
This information can help customize breast cancer screening, depending on a person's risk, including to help determine at what age women are first invited for breast exams or how often they are invited to receive them.
Risk calculation could also help people make decisions about preventive therapy – how to identify high-risk women who may benefit from using tamoxifen – and encourage women to think about ways to reduce their risk.
Dr. Richard Roope, GP specialist at Cancer Research UK, said: "Research like this is extremely stimulating because in the future it will allow us to offer much more personalized care that will benefit patients and make the best use of the services we have available .
"Despite having an increased risk of breast cancer, women are more likely to develop the disease – it is by no means a certainty. A woman at high risk may never get breast cancer, just as a low-risk woman could still. But any woman with concerns should talk to her doctor to discuss the options. "