Testosterone linked to female cancer

Smears can detect cervical cancer

More evidence has emerged that uterine cancer may be triggered by the male sex hormone testosterone.

Until now, the development of the disease appeared to be linked to excessive levels of the female sex hormone oestrogen, with people on early oestrogen-only HRT at higher risk.

It is possible that there could be a greater effect than oestrogen

Dr Helen Mertens, Academic Hospital Maastricht

Approximately 4,000 a year develop the disease in the UK, and 30% of these die within five years.

But a Netherlands-based research team looked at differences between hormone levels in the blood and the blood vessels coming directly from the womb.

They used tissue samples from women who had undergone hysterectomy and ovary removal because of either uterine, or endometrial, cancer, or another benign gynaecological condition.

The team also looked at the endometrial tissue removed from the women, looking for "receptors" for hormones such as oestrogen and testosterone.

These are the parts of the cell which the hormone chemicals approach and join in order to have an effect on the cell.

What they found was surprising - far from oestrogen being the hormone found more frequently in the tissue taken from cancer patients, in fact, testosterone was significantly higher.

And in the malignant endometrial cancer cells, there were fewer oestrogen receptors, and more testosterone, or androgen receptors. In the healthy cells the reverse was true.

While this does not prove that testosterone plays a role in the development of endometrial cancers, it suggests a strong link, and Dr Helen Mertens, of the Academic Hospital in Maastricht, has called for more research.

Hormones

She said: "We found no significant differences in pelvic hormone levels for any of the other hormones or for any of the peripheral levels."

She said: "It is possible that there could be a greater effect than oestrogen."

Another clue is that endometrial cancer is more likely to develop in obese women, and fat is known to be able to convert oestrogen in testosterone, which is why some very obese women have traces of male characteristics, such as more body hair.

But HRT with oestrogen is not yet cleared of blame, even if testosterone turns out to be a cause.

"It may make it worse," said Dr Mertens.

The strengthening testosterone link means that doctors in the future may be able to improve treatment for endometrial cancer.

In another hormone-sensitive cancer, breast cancer, the drug tamoxifen is used to block the action of oestrogen on the cells, thus stifling the growth of the tumour.

Finding hormone-sensitivity in endometrial tumour cells could lead to the development of a similar approach.