New research has revealed that as many as one in three breast cancer cases which are discovered through routine public screening programmes, do not pose a threat.
The research has established a re-surge in the debate over the screening programme, which although saves many women, it can also be more detrimental to others. Doctors report that some women would have benefited more from no treatment but instead they are having unnecessary mastectomies and other treatments.
Two critics of the screening programme, Peter Gotzche of the Nordic Cochrane Centre in Copenhagen and researcher Karsten Jogensen discovered that since screening programmes were introduced in the UK, Canada, Australia, Sweden and Norway, all five countries have developed a similar level of over-diagnosis rates.
The fact that dangerous and harmless cancers cannot be identified, any cancer found is treated.
Screening picks up cancer at an earlier stage, making it easier to treat. The NHS Cancer Screening Service suggests that the programme saves as many as 1,400 lives each year – that’s one for every eight women diagnosed
However researchers argue that for every woman saved, as many as 10 will receive over-diagnosiss and undergo unnecessary treatment and up to 500 will get a false arm as a reasult, half of which will have a biopsy sample.
Gilbert Welch, a professor of medicine at the Dartmouth Institute for Health Policy in the US, says in an editorial published with the research, “The question is no longer whether, but how often, overdiagnosis occurs.
“Mammography is one of medicine’s close calls – a delicate balance between benefits and harms. Mammography undoubtedly helps some women but hurts others. No right answer exists, instead it is a personal choice.”
As part of the NHS programme, women aged 50 to 72 are free to have a screening every three years, however by 2012 the age range is expected to be changed t 47 to 73. Up to 13,500 cancers were picked up in 2006-07 as part of the screening programme.
Critics argues that the £40m spent each year on the programme could be better spent saving more lives with increased treatment.
The Cancer Screening Service is changing their screening advisory leaflet. A spokeswoman added that the updated version will be available later in the year.
Dr Sarah Cant, from Breakthrough Breast Cancer, commented on concerns about the ressearch putting women off from going for screenings, “Based on all the current evidence, we believe the benefits of detecting breast cancer early still outweigh the risks.”