Canadian scientists say that the increased risk of death from invasive breast cancer among younger women who undergo mammography could be caused, in part, by the trauma - severe compression - associated with the procedure.
In a letter to the Lancet, Professor J P van Netten and colleagues at the Royal Jubilee Hospital in British Columbia say ducts in the breast tissue filled with cancerous cells may be ruptured during mammography, and spill into surrounding tissue.
This is of particular concern for younger women. In older women the chances of accidental injury to the breast increase with age, and subsequent injury during examinations may be less important, resulting in a reduction in the death rate in this age-group undergoing mammography.
The doctors are calling for an alternative breast cancer screening method which does not involve compression.