Simple changes to women's lifestyles could prevent one in 10 cases of breast cancer by 2024, say experts.
Breast cancer can be linked to a poor lifestyle
Cutting back on long-term HRT use, keeping in trim, drinking less, and exercising could help prevent 5,700 cases a year, said Cancer Research UK.
Rates have risen by 12% in the last decade - and are expected to carry on rising, researchers believe.
However, getting older is still the biggest risk - and charity Breakthrough urged women to attend screening.
The latest research was carried out by Professor Max Parkin and was presented at the National Cancer Research Institute conference.
Prof Parkin predicted that, without women making changes to their lifestyle, there would be 58,000 diagnoses of breast cancer a year by 2024, compared with 44,000 last year.
"If women begin to make changes in their lifestyle now then by 2024, one in 10 cases could be prevented," he said.
He picked out five main changes that would in theory mean 5,700 fewer cases a year by 2024:
- A cut in prolonged in hormone replacement therapy use
- A reduction in obesity to 1980 levels
- An increase in exercise levels
- A cut in alcohol consumption
- An increase in breastfeeding rates
Long-term hormone replacement therapy has been identified as the most important lifestyle risk factor, and Prof Parkin is hopeful that its use would continue to fall over the next five years.
He said he wanted obesity to return to 1980 levels, when only 8% of women were obese, compared with 23% today.
Another cancer-cutting change, he said, was for all women to exercise for at least 30 minutes five times a week within the next three years - and he called on women to stay within the government's recommendations of no more than two alcoholic units a day.
Finally, Prof Parkin wants almost three-quarters of UK women who have children to breast feed for six months - currently only 21% achieve this.
Sara Hiom, from Cancer Research UK, said: "These calculations show us how lifestyle changes can reduce their risk of breast cancer.
"But every woman will make choices about their health based on their individual circumstances - for instance, there are good medical reasons why some women take HRT where the benefits outweigh the disadvantages."
Gwen Lovell, from Surbiton, was diagnosed with breast cancer in her 50s following a breast scan.
She said that being overweight may have contributed to her cancer - although there could be many other causes.
"I think that if my doctor had told me that being overweight could increase the risk of breast cancer, I would have done something about it - but I don't think it was as well known back then."
Dr Sarah Cant, policy manager at Breakthrough Breast Cancer, pointed out that while lifestyle changes could reduce breast cancer risk other factors, such as genetics and even living environment played a role.
She said: "It's important to remember that getting older is the biggest risk factor for breast cancer and even women with healthy lifestyles should attend breast screening appointments when invited and be breast aware.
"The earlier that breast cancer is detected, the better the chances of successful treatment."