ROUTINE mammogram screening for breast cancer could lead to over-diagnosis of the disease.

Researchers from the Harvard School of Public Health (HSPH) estimate that 15% to 25% of breast cancer cases are over-diagnosed due to regular screening, resulting in unnecessary treatment of the disease.

Its study showed that for every 2500 patients invited to a screening, only one death from breast cancer would be prevented, while six to 10 women would be over-diagnosed and treated with surgery, radiation therapy or chemotherapy without any benefit.

Lead author of the study Mette Kalager said: "Mammography might not be appropriate for use in breast cancer screening because it cannot distinguish between progressive and non-progressive cancer.

"The present study adds to the increasing body of evidence that this practice has caused a problem for women – diagnosis of breast cancer that wouldn't cause symptoms or death."

Women in Scotland are offered mammograms every three years between the ages of 50 and 70.

Breakthrough Breast Cancer Scotland said that despite concerns about over-diagnosis, mammograms remained a vital tool in the fight against cancer.

Charity director Audrey Birt said: ""We believe that screening is vital as it helps detect breast cancer early when treatment options are likely to be less aggressive and have more successful outcomes."