London: Routine mammograms are less effective in detecting breast cancer than expected.
A research, published in New England Journal of Medicine, is the latest to show that the benefits of mammography are limited and will open up debate over the treatment.
The World Health Organisation (WHO) estimates that mammograms reduce the breast cancer death rate by 25 percent in women over 50.
However, the latest review found that while mammograms cut the risk of dying, the benefit was disappointingly low, the Daily Mail reported.
The Norwegian research team said inviting women aged 50 to 69 to have routine mammograms and offering them better care from a team of experts cut the breast cancer death rate by 10 percent.
But the death rate in women over 70 - a group that also got better care but were not urged to have mammograms - fell by eight percent, indicating that the mammograms only produced a slight benefit. The researchers had expected a 30 percent reduction.
"There is a reduction in mortality, but it`s lower than we anticipated," lead researcher Mette Kalager of Oslo University Hospital said.
Some 2,500 women would have to be regularly screened over 10 years to save one life from breast cancer, H. Gilbert Welch of Dartmouth Medical School noted in an accompanying editorial.