HPV is also extremely common: doctors estimate that around 50 per cent of the population carries it at any one time, yet in most cases it is cleared spontaneously by the immune system. Only when the infection persists do signs of abnormality appear on a woman's cervix, signalling that she could be at risk from cancer if not treated. In May, Nature magazine published new research that suggests some women may have a genetic predisposition to the cancer- inducing potential of genital wart infection. As the implications sank in, Katherine's surprise turned to anger. "He seemed to be telling me that, left untreated, these cells could develop into cancer. I couldn't believe I wasn't aware of the risk. I've read articles on cervical cancer in women's magazines for years. None suggested using a condom for protection against cancer."
As long ago as 1986, a group of scientists studied 100 women with low- grade cervical abnormalities and discovered that those who carried a certain strain of human papilloma virus - HPV 16 - were likely to progress more rapidly to high-risk pre-cancerous conditions than those who were HPV negative or carrying a different strain. The study was published in The Lancet and triggered widespread interest within the medical profession. But this information has barely filtered through to the public - despite the fact that doctors are now in little doubt that condoms offer protection.
Patrick Walker is the secretary of the British Society for Colposcopy and Cervical Pathology, the leading authority on cervical cancer, and consultant gynaecologist at the Royal Free Hospital. He argues that for patients like Katherine to realise their abnormal smear is caused by a venereal disease makes them feel worse at a time when it is too late for them to do anything about it. "[Many women with HPV] have a deep shame about the situation... Highlighting the viral associations might do more harm than good." Professor Jack Cuzick of the Imperial Cancer Research Fund was involved in the 1986 study and has since published extensively on HPV. He says, "The fact is, 50 per cent of the population is infected at some time but with most people it clears. So is it useful to try to stop infection with a policy that might not be socially so desirable? People don't usually like to wear condoms. And there are other ways of dealing with the disease."
Should pre-cancerous cells develop, the received wisdom goes, they can be treated. Every year, around 120,000 women are referred for treatment through the NHS screening programme. Generally, they undergo laser therapy or loop diathermy, both of which use heat to destroy the damaged tissue. The procedures offer a 95 per cent success rate. In addition, the cervical screening programme is intended to identify women at risk without the need for additional testing for HPV. Unfortunately, the reliability of that screening programme is now in serious doubt. A National Audit Office (NAO) report published in April 1998 uncovered widespread errors in the NHS cervical screening programme and accused half of all laboratories of misreading thousands of smear test results.
Not only do misread smears result in cancers being missed, they also give many "false positive" results. So, currently, thousands of women are being treated unnecessarily. What's more, the treatment itself is not without risk. After effects include vaginal discharge, abdominal discomfort and heavy bleeding and many women are left feeling uncomfortable about their sexuality. There is also a risk to a woman's fertility, particularly if she is recalled for more than one treatment. Walker says, "Every time you treat you shorten the cervix. There must come a point where the woman's fertility gets compromised."
A screening programme which has been proven to be deeply flawed, treatment which causes discomfort and anxiety and carries a minor risk for long- term health - surely these are good enough reasons to allow women the right to make decisions in full knowledge of the risks? Not according to Professor David Luesley, chairman of the British Society for Colposcopy and Cervical Pathology, who feels it is destructive to cause women further anxiety at an already difficult time. "If something is published which says 'you've got a sexually transmitted disease' we know that has an adverse affect on women in particular. It certainly has an adverse effect on relationships. At the same time as a woman needs a lot of support she's thinking 'my husband's given me something which might kill me. But it might not have been her husband. She could have slept with someone years ago." Then again, she might not have slept with someone years ago - in which case you're looking at one massive domestic row.
HPV poses little risk to men's health. It has been linked with penile cancer, but this is extremely rare. To highlight its threat would single men out for uncomfortable scrutiny while bringing them little real benefit. As for testing men as carriers of HPV, one doctor comments, "It's more difficult to test men. They don't like having scrapes on their penises." Simon Barton, director of Genito-Urinary Medicine at St Stephen's Centre, London, concurs, "So far everyone's been interested in HPV on the cervix. No-one's been interested in HPV in men." If men were targeted as carriers of HPV, they would face new constraints on their sexual behaviour - from using condoms more rigorously to having to make themselves available for regular screening, however unpleasant.
There is some good news. On 5 May, Digene, a European pharmaceutical company, launched a DNA test for HPV which will be available privately to women through Marie Stopes clinics for pounds 95. Digene is also sponsoring a series of trials to be carried out by the Imperial Cancer Research Fund. (Current data shows that testing women for high-risk strains of HPV in conjunction with giving them a routine smear increases the chance of spotting those at risk by 25 per cent.) The combination of the trials and the availability of the test to many more thousands of women could provide the conclusive evidence necessary for the DoH to recommend HPV testing in the national screening programme. At the moment, no-one at the DoH will speculate on when the HPV test will become incorporated into screening. Nevertheless, the availability of a private test should, if obliquely, raise women's awareness of HPV and enable us to make more informed decisions regarding our sexual behaviour. And, for those women who can afford it, there is now a 25 per cent better chance of reducing the risk of cervical cancer.
This article first appeared in the July issue of 'Sibyl' magazine. For subscriptions, call 0171 226 2160Reuse content