Fed: First gene discovered to protect against breast cancer

AAP General News (Australia)
02-12-2007
Fed: First gene discovered to protect against breast cancer

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By Tamara McLean, National Medical Writer

SYDNEY, Feb 12 AAP - Scientists have unearthed a genetic mutation that gives one in
four women a small shield against breast cancer.

This is the first concrete discovery of a common gene linked to the disease, and is
the biggest find for the field since two very rare and high-risk genes were identified
a decade ago.

Australian researchers contributed the international study which found a genetic variation
that gives some women a 10 per cent reduced risk of breast cancer.

Everyone has the gene, called Caspase 8, but 25 per cent of women of European descent
have a mutated variation which gives them a little protection.

And two per cent have two variations, giving them twice the defence.

Leader of the Australian research arm, Dr Georgia Chenevix-Trench from the Queensland
Institute of Medical Research, said the breakthrough was extremely significant.

"This is definitely the first absolutely validated and confirmed low risk gene for
breast cancer," Dr Chenevix-Trench said.

"We've been looking for these kinds of genes for years, with thousand of options put
forward, and now we have one that's definitely real."

It has no immediate implications for women with breast cancer, because there would
be little use in testing for that one gene alone.

But Dr Chenevix-Trench said researchers expected to unearth other similar genes which
women could eventually be screened for.

"My guess is that we'll have a handful of them confirmed with the same degree of confidence
within the next year or two," she said.

"After that we can start to think about testing protocols to see whether it's worth
identifying women who have multiple variants like this.

"Simply having one of them is not enough but if you've got five or six of them in different
genes those are women who might be targeted for earlier and more intensive screening."

Researchers studied nine genes believed to have links to breast cancer and tested the
claims on more then 20,000 women from Australia, the US and Europe, half who had breast
cancer.

The results, published today in the journal Nature Genetics, report that eight had
either no or marginal evidence of a link, with only Caspase 8 standing up to robust investigations
by the 20 research groups.

Scientists believe the find is the biggest since the 1990s discovery of the rare BRCA1
and BRCA2 genes which lift a woman's chance of the disease by 60 per cent.

"There's been nothing since then but false starts until now so the field was starting
to get a bad name," Dr Chenevix-Trench said.

One in 12 Australian women will get breast cancer, and 2,500 die each year, making
it the most common cancer in females.

AAP tam/arb/bwl

KEYWORD: BREAST (EMBARGOED)

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