Jeremy Laurance: Checking for breast cancer is best left to experts

Being told to examine your breasts every month soon becomes burdensome and worrying

It is no accident that of all the cancers, those affecting the breast attract the most attention – something that is commensurate with the public interest in the organ. Breast cancer attracts one hundred times as much state research funding as prostate cancer, although both diseases claim similar numbers of lives (10,000 a year from prostate cancer and 12,000 from breast cancer). It is the prostate's misfortune that it is neither visible nor voluptuous.

It is no accident that of all the cancers, those affecting the breast attract the most attention – something that is commensurate with the public interest in the organ. Breast cancer attracts one hundred times as much state research funding as prostate cancer, although both diseases claim similar numbers of lives (10,000 a year from prostate cancer and 12,000 from breast cancer). It is the prostate's misfortune that it is neither visible nor voluptuous.

But while the extra funding has bought significant gains against breast cancer, with a sharp fall in the death rate, there is a downside in increased anxiety for the millions of women who will never get the disease but fear they might.

The latest study, published yesterday, showing that self-examination of the breast offers no defence against the disease will add to women's feeling of powerlessness. It was a huge 11-year study of 266,000 women in Shanghai, and it found that death rates were the same among those who were taught to examine their breasts and those who were not.

So breast self-examination is useless. In truth, this is something we have known for a long time. In the UK, the health department formally abandoned the policy of advising women to examine their own breasts each month in 1991, after studies failed to show that it was worthwhile.

In the United States, where there is no policy on breast self-examination, researchers from the Fred Hutchinson Cancer Research Centre decided to settle the issue once and for all. They chose China for their study because women there have no access to X-ray mammography, which would have muddied the results.

One of their most striking findings was that the women taught to examine their breasts did identify more lumps, but they were more often benign. So they endured the anxiety and discomfort of having the lumps investigated and, in some cases, removed, without reducing their risk of cancer.

In Britain, mammography is the favoured defence against breast cancer for women over the age of 50 because of its capacity to spot smaller lumps than can be felt with the hand and to distinguish better which are cancerous and which are benign. Its discriminatory powers are still a long way short of perfect, however. Tens of thousands of women who are recalled each year for further investigation following suspicious mammography turn out to have nothing wrong with them. Sometimes ignorance is the healthiest option.

Importantly, while mammography reduces the risk of dying from breast cancer, it does not eliminate it. Not all cancers are detected. And some may develop in the interval between screenings (which is normally three years). Women typically have an unrealistic idea of the protective effect of screening, believing, according to a recent survey, that it cuts their risk of dying by 75 per cent. The true figure is less than half that 75 per cent.

This has raised doubts about the value of mammography – doubts, more widely aired in the US than in the UK, over whether mammography saves lives or prompts unnecessary treatment. It comes down to a question of where the balance lies, and, just as important, whose interests are being served.

It is this debate that has fired up critics of mammography in the US. So many professional interests, and so many billions of dollars are now wrapped up in the screening programme, that they fear the evidence for and against will not be viewed dispassionately. The New York Times called for an open debate on the issue earlier this year but warned in an accompanying editorial: "Mammography has been so strongly endorsed by the cancer establishment and has become such a significant source of revenue for many hospitals and doctors that it may be difficult to excise without overwhelming evidence that it is dangerous."

In an attempt to settle the argument, the World Health Organisation convened a panel of 24 experts from 11 countries who concluded last March that breast screening cut deaths from breast cancer by 35 per cent among women aged 50-69 who attended regularly for screening.

That is good news. But the mistake is for a woman to believe that because she has been cleared by screening, she won't get cancer. She might. She still retains two-thirds of her original risk of breast cancer despite being screened.

So what else can a woman do to protect herself? If examining the breasts is something best left to experts or technology, there may be something liberating in that. As Delyth Morgan, the chief executive of Breakthrough Breast Cancer Care put it, being told to check your breasts on the fourth Thursday of each month soon becomes burdensome – and worrying, too, if you fear you may not be doing it right.

So the message to women from the health department and the cancer charities is instead to become "breast aware". This means noting the normal size, shape and texture of the breasts and looking out for any changes.

Many women may wonder how this can be an improvement on regular breast self-examination. Surely a woman who checks her breasts each month in a methodical way is going to be more "breast aware" than one who doesn't? But this is to miss the point. The strategy is not about improving detection but about reducing unnecessary anxiety and needless investigations.

For a few women, who are sufficiently motivated to conduct a regular, methodical examination of their breasts each month, it may help spot cancers early. But for the majority, it won't. And there is then no justification for advising them to carry it out, given that it is a tiresome ritual that may cause undue worry and concern and lead to increased investigations of what turn out to be benign lumps.

Many women will be naturally aware of their breasts and how they change during the monthly cycle and will need no encouragement to report unusual changes to their GP. But for some, their lack of awareness means that they are slow to go to the GP and slow to get treatment, and their chances of a cure, should they develop cancer, diminish.

A survey by Breakthrough Breast Cancer last month found one in three women did not know what they were supposed to be looking out for when exhorted to be breast aware, and one in seven never checked their breasts at all. Older women tended to be the most reluctant, although theirs is the group in which breast cancer is most common.

The message of that survey was that no matter how great the advances in treatment, they are unlikely to reduce the toll from the disease unless the women affected get down to their GP at the first sign of a reddened nipple. And that raises the question of whether it is genuinely in women's interests, or in the interests of the doctors, charities and professional organisations involved in treating breast cancer, to foster the continuing sense of alarm about the disease.

So women need to be aware, but they do not need to be frightened. Like the rest of us, they should have a healthy interest in their bodies, not an unhealthy fear of them.

j.laurance@independent.co.uk