Cancer expert remains to be convinced by breast screening review

Michael Baum, Professor emeritus of surgery at University College London says that, while deaths from breast cancer may be avoided, any benefit will be more than outweighed by deaths due to the long term adverse effects of treatment.

He estimates that, for every 10, 000 women invited for screening, three to four deaths are avoided at the cost of 2.72 to 9.25 deaths from the long term of radiotherapy.

These figures contrast with an independent report on , led by Sir Michael Marmot and published in November last year. Marmot and his committee were charged with asking whether the screening programme should continue, and if so, what women should be told about the risks of overdiagnosis.

They concluded that screening should continue because it prevented 43 deaths from breast cancer for every 10,000 women invited for screening.

The downside was an estimated 19% rate of overdiagnosis: 129 of the 681 cancers detected in those 10,000 women would have done them no harm during their lifetime. However, those women would have undergone unnecessary treatment, including surgery, radiotherapy and .

But despite this higher than previous estimate of overdiagnosis, they concluded that the programme should continue.

The report also judged that screening reduces the risk of dying from breast cancer by 20%. But Professor Baum disputes these figures, saying the analysis takes no account of improvements in treatment since these trials were done, which will reduce the benefits of screening. Nor does it make use of more recent .

With these data included, estimated rates of overdiagnosis as a result of screening increase to up to 50%, he argues.

This is important because it can change the decisions women make when invited for screening. In a study also published today, researchers at the University of Sydney explored attitudes to screening in a sample of 50 women. Many of the women were surprised when they were told about overdiagnosis and most said they would attend screening if overdiagnosis rates were 30% or lower, but a rate of 50% made most of them reconsider.

An accompanying editorial points out that the harms of screening will reduce as more effective diagnostic processes develop to inform less harmful and more personalised treatments. In the meantime, it says women need up to date and transparent information about the benefits and harms of screening to help them make informed choices.

add to favorites email to friend print save as pdf

Related Stories

Informing women on breast cancer overdiagnosis

Jan 24, 2013

In a study exploring women's responses to being told about overdiagnosis in breast cancer screening, most women felt the information was important and could enable them to make choices.

Recommended for you

Discovery could lead to new cancer treatment

23 hours ago

A team of scientists from the University of Colorado School of Medicine has reported the breakthrough discovery of a process to expand production of stem cells used to treat cancer patients. These findings could have implications ...

Is the HPV vaccine necessary?

Aug 29, 2014

As the school year starts in full swing many parents wonder if their child should receive the HPV vaccine, which is recommended for girls ages 11-26 and boys 11-21. There are a lot of questions and controversy around this ...

User comments