Vital clue to cancer cause

Press, 5 August 1983, Page 18

Vital clue to cancer cause

By

OLIVER GILLIE

“Sundy Times,” London

A condition doctors have hitherto dismissed as a mere nuisance is now thought to be the most likely cause of cancer of the cervix — the neck of the womb. Several studies suggest that genital warts, which are three times as common as herpes, are to blame. If they are, the doctors would be able to control the disease much better, if not prevent it. At present, cervical cancer is detected in its early, treatable stage in almost 10 women in 1000 in Britain. Despite a huge screening effort by health services, more than 2000 women a year still die from the disease and in the youngest age-group deaths have shot up threefold in recent years. In future, when a smear test shows a woman has the disease, her husband or lover will probably be called in for wart checks.

In the past five years, the number of people seeking treatment for genital warts has increased by almost a third. This suggests there will soon be a large increase in the number of women getting cervical cancer or being found by screening tests to have the early stage of the disease.

Other research reinforces the link between genital warts and

cervical cancer. It has long been known that the more sexual partners a woman has or the more her partners have, the greater the risk she will suffer cervical cancer: Even a woman who has only one partner may be put at risk if that partner has intercourse with other women. Women who begin their sex-life young have also been found to be at greater risk. All this points to an infectious agent being the cause of cervical cancer. Other evidence points to genital warts being that agent because it is associated with cervical cancer four times more often than are other conditions such as gonorrhea or herpes. There are at least 16 different types of wart virus. The type that causes raised warts mainly on the hands has not so far been found to be linked with cervical cancer.

It has been known for years that wart viruses cause cancer in animals. Cows, for example, get internal warts that can turn malignant if the animals eat a lot of bracken.

It is also thought that other human cancers could be caused in the same way — particularly skin cancer. It now seems ultraviolet light may cause the disease only when combined with a wart infection which may not be noticeable.

Now that the link between warts and cervical cancer is known, women who have genital warts or other sexually transmitted diseases may be sought out for regular screening. Screening clinics for cervical cancer that take all comers have in some areas found too few cases to be worthwhile. A war on warts promises to be more successful.

Evidence implicating genital warts came first from Germany. Dr Harald zur Hausen and colleagues at the Institute for Virology at the University of Freiburg, found a genital warts virus, HPV 11, within diseased cells taken from the cervixes of 11 out of 18 cancer patients. Another three women were found to have a different

variety of wart virus and it seems likely that further work will discover other varieties.

The genes (DNA) of the wart virus had become intimately associated with the DNA of the women’s body cells and could be detected only by elaborate genetic engineering. This suggests the virus was responsible for the malignant change in the cells. These findings, published in the Proceedings of the United States National Academy of Sciences in May, are creating great interest among cancer researchers. Sceptics may say the wart virus is merely a passenger in sick cancer cells, but British doctors and scientists who have collaborated with the Germans support their observations. The British research was done by a team from three London hospitals: Denis McCance at Guy’s working with Albert Singer; Patrick Walker and Jennifer Dyson at the Royal Northern Hospital; and Dulice Coleman at St Mary’s. They found a genital wart virus in 13 out of the 22 women at the Royal Northern who had premalignant changes in their cervixes. This again suggests that the virus is involved in the process that turns a normal cell cancerous. £