The number of women under the age of 50 who are diagnosed with breast cancer is on the rise, a charity has warned.
In 2010, 10,068 women under the age of 50 in the UK were told that they had the disease - 2,300 more than the number diagnosed in 1995, said Cancer Research UK.
The charity said that one in five breast cancer cases are now among women under the age of 50.
While the reason behind the increase is unclear, the charity suggested that a rise in alcohol intake, the use of the contraceptive pill and women having fewer children and in later life could be to blame.
Routine screening for breast cancer is currently offered to women aged 50 to 70 but recent changes to the programme will see those in their late forties also invited.
Sara Hiom, of Cancer Research UK, said: "Breast cancer is more common in older women but these figures show that younger women are also at risk of developing the disease.
"Women of all ages who notice anything different about their breasts, including changes in size, shape or feel, a lump or thickening, nipple discharge or rash, dimpling, puckering or redness of the skin, should see their GP straight away, even if they have attended breast cancer screening. It's more likely not to be cancer but if it is, detecting it early gives the best chance of successful treatment.
"The number of cases in women under 50 diagnosed with breast cancer is increasing slowly, but thanks to research, awareness and improved care more women than ever before are surviving the disease."
Chris Askew, of Breakthrough Breast Cancer, said: "These figures show that breast cancer still affects more and more families every year in the UK and the need for research into the disease remains vital. Although breast cancer is more common in older women, it's worrying to see an increase in the number of younger women diagnosed with the disease.
"More women than ever are surviving which is great news. However, more women are getting breast cancer and we must invest in vital research for new treatments and disease prevention."