A new study has added to growing evidence that yearly mammogram screenings do not reduce the chance that a woman will die of breast cancer and confirms earlier findings that many abnormalities detected by these X-rays would never have proved fatal, even if untreated.
The research, published on Wednesday in the British Medical Journal, is the latest salvo in a decades-long debate over the benefit of mammograms. The 25-year study of 89,835 women in Canada, aged 40 to 59, randomly assigned the volunteers to receive either annual mammograms plus physical breast exams or physical exams alone.
The women started receiving mammograms from 1980 to 1985. At the time, doctors believed screening saved lives by detecting early-stage cancers, which were considered more treatable than cancers detected later, especially in women aged 50 to 64.
Instead, the study “found no reduction in breast cancer mortality from mammography screening,” the scientists wrote, “neither in women aged 40-49 at study entry nor in women aged 50-59.”
