Tuesday, August 31, 1999 Published at 23:00 GMT 00:00 UK
Ovary removal 'cuts breast cancer risk'
An operation might reduce the risk of breast cancer for some
Women carrying a gene associated with breast cancer greatly cut their risk of developing the disease if they opt for an operation to remove the ovaries, research suggests.
But a leading breast cancer charity has said that rigorous counselling must be provided before women take such a serious step.
The research indicates that genetic screening may be effective, although earlier studies suggest that women are unlikely to go ahead with surgery even if told they have the rogue gene.
Two genes, BRCA1 and BRCA2, are thought to be responsible for between 5-10% of all new breast cancer cases diagnosed in the UK.
The latest study, from the University of Pennsylvania Cancer Center, focuses on the BRCA1 gene.
Risk reduced by two-thirds
Researchers found that the ovary removal operation, or oophrectomy, reduced the risk of developing breast cancer by 70%.
This is because the hormone oestrogen, produced by the ovaries, is known to have an effect on the development of breast cancer cells.
He said: "However, we ultimately hope to identify a non-surgical means of achieving the same result, and we highly advocate that any woman considering a bilateral oophrectomy get counselling before undergoing the procedure."
Some women who find out they have a hereditary pre-disposition to breast cancer choose to have their breasts removed rather than risk developing the disease.
However, a study in the Lancet in June found that most women who test positive for a BRCA mutation do not go on to have surgery.
But Delyth Morgan, chief executive of Breakthrough Breast Cancer, said that the removal of ovaries was a "drastic and permanent" measure.
"Doctors recommending surgery to high risk women must ensure that they receive adequate counselling and are aware of alternative options."
Future lies in drugs
She said the real worth of the study was reinforcing the message that drugs which blocked oestrogen could prevent breast cancer.
"From this we can look at ways in which drugs work and therefore find non-surgical methods of reducing the risk of breast cancer."
The best known drug which is believed to block the action of oestrogen on breast tissue is Tamoxifen and some studies have shown that it does have a protective effect, although this claim is still controversial.
Approximately 30,000 women are diagnosed with breast cancer in the UK every year.