11 FEBRUARY 1989, Page 20


Sharon McCullough questions the

value of mass-screening for breast and cervical cancer

THREE days after the plans for the new-look NHS were formally unveiled, the British Medical Journal published a report which shows that cervical cancer in young women is increasing. Up, went the familiar public cry, 'We need more screening.' But a government committed to getting better value for money would do well to consider the whole screening campaign more care- fully.

Like most GPs I am spending a lot of my time these days Well-Womanising. Busi- ness is booming. Well-Woman Clinics are fully booked. Clerical staff setting up computerised recall systems and doctors are working hard to improve practice take- up rates. We're all very busy and it feels good. Receptionists, nurses, doctors and the state united in the fight against cancer of the breast and cervix.

On the front line the battle cry is prevention. Armed with a speculum and a mammography referral form, it is as easy to get carried away with the whole crusade as it is to get carried away with a metaphor. Not that it would matter if the battle were being won. Sadly the major casualties in this war are the women that the screening arsenal was designed to protect.

The mammogram and the cervical smear are technically safe tests, but the shrapnel starts to fly as the invitation to attend the clinic hits the doormat. Cancer still terri- fies. A recent survey has shown that around half of the traceable non- responders to a cervical screening call failed to attend through fear. These women believed that the request to attend meant that their doctor knew they already had cancer.

Many women who do undergo breast and cervical screening find the tests un- comfortable and embarrassing. They en- dure the indignities of such intimate ex- aminations and the anxieties engendered by the long wait for the results without complaint. Most of them think it is worth it for the reassurance of a clear test. They might change their minds if they knew how just how accurate the tests were.

Smears and mammograms only detect about 80 per cent of malignancies. A fifth of those women unlucky enough to have breast or cervical cancer will be missed. They are the doubly unlucky 'false nega- tives'.

The women who have been told they have an abnormal smear or mammogram all believe they have cancer. After all, everyone knows that is what the tests are for. They experience tremendous stress and anxiety as they await further investiga- tion. For most of them the suffering will be unnecessary. Ninety-five per cent of abnor- mal smears and mammograms are not cancerous though a woman may require colposcopy or biopsy to prove it. If she is eventually given the all-clear, she will only be temporarily reassured. Once caught up in the system, her fears and worries will return with every recall card.

The suffering of individuals, though re- grettable, might be justified if it meant that we were stopping more women from dying. But we are not. Since cervical screening was introduced in 1964 the mortality rate for carcinoma of the cervix has fallen by one per cent each year. It had been falling at exactly the same rate for several decades before. Countries with no national screen- ing system such as Japan, France and Italy have noticed greater falls in mortality rates. There is little reason to suppose that a breast screening programme will fare much better. Despite 'advances' in radio- and chemo-therapy we have not managed to reduce the mortality figures for breast cancer over the last 100 years.

Assessing the value of any intervention is virtually impossible given the present lack of knowledge of the natural history of breast and cervical malignancy. Until re- cently we assumed that all pre-malignant cervical lesions would eventually become invasive. It now looks as if around 95 per cent of them rarely progress and that most of the invasive lesions are associated with two particular strains of the human papillo- ma virus.

Breast cancer seems to exist in two distinct forms. Young women often pre- sent with a virulent illness in which micro- metastases may have occurred by the time of diagnosis. The elderly tend to develop a more benign form which is slow to metasta- sise. Breast cancer is the commonest cause of death in women aged between 35 and 49, but screening will only be offered to those over 50. Mammography is useless in dense young breasts. The mortality rate for carcinoma of the cervix is more than 15 times greater for women over 45 than those below. Nearly all of the women dying from the disease have never had a smear. Yet the clinics are full of the young, informed 'worried well'. And if a young woman fails to present herself then we seek her out at family planning or ante-natal clinics. The older, biologically redundant woman is overlooked.

The cost of the cervical screening prog- ramme is £30 million a year; a drop in the ocean of the NHS finances. But to prevent one death from cervical cancer, 40,000 smears and 200 biopsies must be per- formed. A Lancet editorial described this as a 'grievously poor' cost-benefit ratio. The proposed national breast screening campaign will require a yearly budget of at least £100 million pounds. It will be less cost-effective than screening for lung can- 'Death on the Rocks, please.' cer which, due to the low survival rates, has never been seriously considered. Even so, lung cancer kills almost as many women as breast cancer and is completely prevent- able. More young women are smoking than ever and the Health Education Au- thority will need more than its miserly annual £10 million grant if it is to compete with the advertising budgets of the cigarette manufacturers. The Aids cam- paign has shown that health education can work, but no one imagines that it will win votes. On the other hand active screening programmes prove that the Government cares about women.

There is a lot of well-womanising going on but not much to show for it. For years now a predominantly male medical profes- sion has been encouraging the wrong Women to attend for inaccurate screening tests. No one knows how to interpret the results or whether any of it has done any good. It is costing us all millions of pounds.

Women are being told that screening is good for them by doctors who are too busy crusading to think. Zealously x-raying breasts and smearing cervices, we have become the white-coated heroes of the battle for women's health. If we were honest we would admit that all we are doing is making ourselves feel better. Self-gratification at the expense of women is an age old army pastime. There's no Well-' about it, it is just plain womanising.