Questions raised about breast cancer screening.

Around 20 years ago, I attended a lecture on screening by Dr Martin Allbright (of Malvern) The lecture has stuck in my mind because of Martin's excellent teaching and also because what he was saying was quite controversial at the time and made a lot of sense to me. In the early 90s, mammography was fairly new and the NHS had invested huge sums of money in it. Martin Allbright said that mammography did not meet ANY of the criteria for an effective and safe screening programme.

1) It should be easy to administer.

It obviously isn't.

2) It should not cause problems itself.

The crushing of the breasts can break up tumours and cause cells to travel to distant sites.

3) It should not give unacceptable numbers of false positives and negatives.

It does

4) It should be relatively inexpensive.

It isn't.

5) It should not cause pain and distress.

Ask any man to place his testicles on a piece of flat metal and have them crushed flat and you'll find that the very suggestion causes pain and distress! Yet this is exactly what mammography does to breast tissue. That anyone could believe that this does not cause pain and distress and damage to delicate breast tissue is beyond me!

The Independent carries a report of a review into this screening process.

The Independent

The review does not focus on the harm caused by the process itself, but the dangers of overdiagnosis and unnecessary treatment. It's a long article and I shall just pick out a few paragraphs.

The success of the national breast screening programme which offers tests to almost two million women a year has been called into question by a review which says it is harming almost as many women as it helps and must be urgently re-evaluated.

The benefits of breast screening – early detection of cancer followed by rapid treatment – are finely balanced against the harms of overdiagnosis followed by unnecessary treatment and suffering, and have never been properly weighed against each other, the review by a leading epidemiologist says.

The stark conclusions mark a new phase in the war over breast screening, which has divided the medical establishment for more than 20 years. But they also raise questions about all screening programmes, including those for bowel, prostate and cervical cancers, which similarly bring harm as well as benefit.

The simmering dispute between the two sides boiled over last March, when the British Medical Journal published a paper on breast screening in Denmark which showed that deaths from breast cancer had fallen faster in areas without screening than in those where it was used.

It concluded that the decline in the breast cancer death rate was "more likely explained by changes in risk factors and improved treatment than by screening mammography".

"There is no doubt that screening for breast cancer has limited benefit and some possibility of harm for an individual woman and is of marginal cost-effectiveness for the community... The NHS screening programme needs to be really clear about the uncertainties when communicating with women... More importantly we all need to understand better how a national programme of such importance could exist for so long with so many unanswered questions."

Ms Godlee said: "I don't think the public understands that screening carries both risks and benefits. Often doctors don't either – they are caught up by the notion that prevention is better than cure. If you are intervening with a healthy population in the hope you can make their lives better and longer then the burden of proof is much higher and the strength of the evidence you need greater."