Breast cancer patients ‘treated needlessly’

UP to a quarter of breast cancer cases detected during X-ray screening are ‘overdiagnosed’ and would not have caused symptoms in the woman’s lifetime, researchers claim.

They found that many healthy women are getting an unnecessary diagnosis of pre-cancerous conditions that are unlikely to develop.

But they are receiving treatments that can cause harm including surgery, radiotherapy and chemotherapy.

Between 15 per cent and 25 per cent of breast cancer cases are overdiagnosed dur- ing routine mammography screening, the researchers estimate. Study author Mette Kalager said: ‘Mammography might not be appropriate for use in breast cancer screening because it cannot distinguish between progressive and non-progressive cancer.’

Almost two million women in the UK are screened each year. But the study is the latest to question whether screening causes more harm than good, with improvements in breast cancer survival more attributable to advances in treatment.

Researchers from the New Harvard School of Public Health in Boston analysed data from nearly 40,000 women in Norway.

For every 2,500 women invited for screening, the vast majority were given the allclear, an estimated six to ten were overdiagnosed, 20 were properly diagnosed and one death from breast cancer was prevented.

The findings were reported in the journal Annals of Internal Medicine.