One in seven women could develop breast cancer if public health trends do not improve, experts warn.
Researchers found the risk to women carrying a gene which can lead to the disease has increased dramatically in the last 60 years.
The study, at the Genesis Breast Cancer Prevention Centre in Manchester, suggests a lifestyle change is key.
Having families earlier and avoiding long term use of female hormones in HRT and contraceptives were recommended.
Experts also suggested regular exercise and a healthy diet could make a difference.
One in 10 women in the UK currently develop breast cancer by the age of 80 but researchers fear this may rise to one in seven by 2024 unless changes are made.
Gene mutations
Around one in 500 people are said to carry the gene mutations which result in an 85-90% chance of developing breast cancer.
Professor Gareth Evans, who led the study of more than 1,400 women who carried the high-risk genes, said: "This rise in the incidence of breast cancer is reflected in the general population.
"In 1984 only one in 13 women were projected to develop breast cancer.
"In 2004 this reached one in 10 and, if the rates rise as they are currently doing so, it is predicted that by 2024 one in seven to eight women will develop breast cancer by 80 years of age.
"That will translate into an extra 4,000 deaths, unless further improvements in treatments occur."
The report, by the consultant in medical genetics at St Mary's Hospital and Christie Hospital, both in Manchester, will be published in the BMC Cancer journal.
It showed that women born before 1920 who carry faults in the high-risk genes had a 7.5% chance of developing breast cancer by the age of 40.
However, women born after 1960 had a risk of up to 40%.
The Genesis Appeal, a breast cancer prevention charity, has funded the purpose-built £14m centre in Wythenshawe which brings together medical experts to conduct diagnosis, education and research into the disease.
Researchers found the risk to women carrying a gene which can lead to the disease has increased dramatically in the last 60 years.
The study, at the Genesis Breast Cancer Prevention Centre in Manchester, suggests a lifestyle change is key.
Having families earlier and avoiding long term use of female hormones in HRT and contraceptives were recommended.
Experts also suggested regular exercise and a healthy diet could make a difference.
One in 10 women in the UK currently develop breast cancer by the age of 80 but researchers fear this may rise to one in seven by 2024 unless changes are made.
Gene mutations
Around one in 500 people are said to carry the gene mutations which result in an 85-90% chance of developing breast cancer.
Professor Gareth Evans, who led the study of more than 1,400 women who carried the high-risk genes, said: "This rise in the incidence of breast cancer is reflected in the general population.
"In 1984 only one in 13 women were projected to develop breast cancer.
"In 2004 this reached one in 10 and, if the rates rise as they are currently doing so, it is predicted that by 2024 one in seven to eight women will develop breast cancer by 80 years of age.
"That will translate into an extra 4,000 deaths, unless further improvements in treatments occur."
The report, by the consultant in medical genetics at St Mary's Hospital and Christie Hospital, both in Manchester, will be published in the BMC Cancer journal.
It showed that women born before 1920 who carry faults in the high-risk genes had a 7.5% chance of developing breast cancer by the age of 40.
However, women born after 1960 had a risk of up to 40%.
The Genesis Appeal, a breast cancer prevention charity, has funded the purpose-built £14m centre in Wythenshawe which brings together medical experts to conduct diagnosis, education and research into the disease.
