Breast cancer screening revealed to be harming thousands
An independent review has shown that for every one life saved by breast cancer screening, three women endure treatment for a tumour that would have caused them no harm.
The review, undertaken by an independent panel led by Professor Michael Marmot from University College London, has been published in The Lancet Medical Journal. The results showed that while mammogram screening saved 1,307 lives in the UK alone last year, it also led to 3,971 women undergoing treatments that were unnecessary, giving each patient a one per cent chance of over-diagnosis.
This over-diagnosis comes from screening that identifies tumours that otherwise would have left the woman. As a result, a number of women are unnecessarily undergoing treatments such as hormone therapy, chemotherapy, radiotherapy and surgery – all of which entail severe side effects.
With over two million women screened for breast cancer each year, of whom 48,000 are diagnosed with the disease, Professor Sir Mike Richards, National Cancer director, says mammograms are “an area of high controversy” with the debate revolving around ‘‘over-diagnoses’’.
He told the BBC: “My view is that the screening programme should happen, we should invite women to be screened and give women the information to make their own choice.”
Richards says leaflets on breast cancer and screening will be updated over the next few months, “to give the facts in a clear, unbiased way”. This reinforces a statement by the government, which states that all the information will be on new leaflets to give women an “informed choice.”
Dr Harpal Kumar, chief executive of Cancer Research UK, said in a press statement: “The review shows screening saves lives. As the review shows, some cancers will be diagnosed and treated that would never have caused any harm. Clearly, everyone wants to minimize this.
“Because we cannot yet tell which cancers are harmful and which are not, we cannot predict what will happen in an individual woman’s case. So, on balance, taking all the evidence into account, Cancer Research UK recommends women go for breast screening when invited.”
Professor Michael Marmot said: “Screening has contributed to reducing deaths but resulted in over-diagnosis. It’s vital women are told about risks and benefits before mammograms.”