Breast screening harms as many as it saves: report
The UK’s national breast screening programme is harming almost as many women as it helps and must be urgently re-evaluated, a review in England has claimed.
The benefits of breast screening — early detection of cancer followed by rapid treatment — are finely balanced against the harms of over-diagnosis followed by unnecessary treatment and suffering, the review says.
Breast screening has divided the medical establishment for more than 20 years.
The central drawback of screening is that in some cases the cancer (or other disease) detected does not need treating, either because it is a false alarm, because it resolves naturally or because it is very slow growing (so you die of something else).
Supporters say it prevents an estimated 1,400 deaths a year. They claim that breast screening saves two women's lives for every one who gets unnecessary treatment.
Critics dispute these figures, claiming that for every woman saved, as many as 10 undergo unnecessary treatment.
Last March, the British Medical Journal (BMJ) published a paper on breast screening in Denmark which showed that deaths had fallen faster in areas without screening.
Researchers were accused of “undermining trust”.
Fi Godlee, editor of the BMJ, asked Professor Klim McPherson, public health epidemiologist of Oxford University, to review the evidence, and the results are published in the BMJ's current issue.
Prof McPherson, citing US evidence, says breast screening reduces the death rate by 14% in the under-60s — “marginal statistical significance” — and by 32% in under-70s. But this is a small benefit because at age 60 the risk of death from breast cancer over the next 15 years is just 1.2% — 259 women in the UK would have to be screened to avoid one death.
He calls for a “full examination of all the data” and more honesty from the NHS about the scientific uncertainties.