An alternative target for screening could cut costs and reduce unnecessary trauma, writes Patsy Calton MP

If you could have a health test that was over 90 per cent reliable, where the result could save your life, you would have it wouldn't you? Furthermore, if the test was more useful than existing tests, and could save the country a lot of money and women unnecessary trauma, you'd say what are we waiting for - wouldn't you?

Human Papilloma Virus (HPV) testing is currently available as a privately paid for test. It is sensitive enough to pick up the strains of HPV that are present in 99.7 per cent of all cases of cervical cancer, a disease which is widely recognised as a sexually transmitted disease, rarely diagnosed in the absence of HPV. It has been argued that testing for the presence of HPV is potentially far more useful than cervical smear testing because its presence can be used as a likely predictor of cervical cancer. Its absence indicates cervical cancer is unlikely in women who have only one partner, where the partner has no other partners.

The current mass screening smear test for cervical cancer has saved large numbers of lives. An individual test is only 60 per cent reliable but repeated tests, at regular intervals, are likely to pick up all but the most invasive, fast growing cancers. Half of all cervical cancers occur in women with a negative smear test. The test depends on a good sample of cervix cells smeared on a glass slide and recognition of abnormal cells by a trained person, who spends all day looking down a microscope, scanning the slides for the tell tale signs.

Women are recalled for a further test if abnormal cells are observed, or if the test sample is inconclusive. One in 12 women are recalled because of inadequate smears. It can take as long as six months for a repeat test, depending on where you live. Does this matter? Will the delay make any difference to the outcome?

In human terms the delay leads to anguish, depression, stigma and living with uncertainty. It also costs the Health Service large sums in anti-depressants given to women to help them cope with the prospect of a life-threatening disease contracted either because they, or their partner, have had other partners.

A six-year trial that has just started at St Mary's Hospital in Manchester aims to determine whether HPV testing will enable more reliable, rapid identification of those most likely to develop cervical cancer, and whether it is necessary to routinely screen women who are HPV negative. Twenty-eight thousand women will be recruited to the trial, starting with women in the 20-29 age group.

The HPV test experience is similar for the woman to a smear test. A sample of cells from the cervix is obtained by scraping the cervix, but the difference is that the cells are transferred to a liquid in a tube instead of smeared on a glass slide. The cell sample can be used to check for abnormal cells, in just the same way as a smear test. Companies producing the liquid based test kits, not surprisingly, want to sell them as a straight replacement to smear testing - with the potential to be used for HPV testing as well.

It has been suggested that £30 million a year could be saved if the HPV test was performed on all borderline or inadequate smear tests: women with negative HPV tests would not need to be recalled.

It is possible that the HPV test could replace the traditional smear test. If it does, regular testing may prove unproductive and unnecessary - younger women or those with changes of partners might choose to be tested: women in stable monogamous relationships would gain no benefit from routine testing. However as many as a third of all women have HPV infection at some point - and most will not go on to develop cervical cancer. The body's immune system deals with most infections. A positive HPV test would not mean treatment was necessary: merely that regular checks would be advisable.

The Health Service could save large sums of money by targeting its resources on those most likely to develop cervical cancer. The HPV test allows that prediction to be made and unnecessary tests to be reduced. A further saving would come from the reduction in uncertainty, and reduced need for antidepressants, experienced by women waiting for a second test after recall.

My own correspondence with women who have been recalled for further testing for cervical cancer has shown that it is a tremendously traumatic experience for them. What women want is certainty. The largest response rate we have had to any petition in my constituency was to one calling for HPV testing. It is a big issue for a great many women. In 1996-7 200,000 women had a borderline smear test: 100,000 were referred for examination, at a cost of £26 million. Only 4,000 were diagnosed with invasive cervical cancer that year - 1300 died.

How much longer do we have to wait?