Cancer genes are ‘not a death sentence’
Australians are surviving to a healthy old age despite having genes that cause cancer or heart disease, a breakthrough study has found.
It means women with genes linked to breast and ovarian cancer like Angelina Jolie may be having their breasts and reproductive organs removed to prevent a cancer they may never develop.
They may live a long life because they have other protective genes that counteract cancer causing genes disease, the Australian research found.
The author of the study, Monash University's Dr Paul Lacaze, said it proves that carrying cancer causing gene variations like BRCA1/BRCA2, Lynch's Syndrome or 50 other pathogenic gene variations is "not a death sentence".
He is now racing to identify other genetic variations that might explain why these people did not develop cancer in order to fine tune the usefulness of genetic testing for disease.
It could eventually lead to some women being told that even though they have a BRCA gene, their risk of cancer is still low so drastic action like breast and ovarian removal is not necessary.
Regular cancer checks might be all they need to protect themselves.
"They might actually be stratified into low, medium and high risk based on the rest of the genome. So that's what we were we hope to get to, in coming years, is a more nuanced measure of genetic risk," Dr Lacaze said.
Women with BRCA genes have a 70 per cent chance of developing breast cancer so it is important they seek medical advice about preventive surgery.
Krystal Barter from breast cancer charity Pink Hope said preventive surgeries were drastic and welcomed any research leading to prevention.
"If you don't need to have them and you have more information that enables you to make more appropriate decisions, it's going to be better for everyone so you know this is excellent research," she said.
She said she knew of a family where a mother lost two daughters to breast cancer when they were in their thirties. The mother carried the same BRCA gene, but reached her late sixties without ever developing breast cancer.
The Monash research analysed genetic markers in 13,000 healthy Australians aged over 70 who are taking part in the ASPREE study.
These people had no history or symptoms of cardiovascular disease, no current diagnosis of cancer (they may have had a previous cancer that had cleared), no evidence of dementia or cognitive decline, or permanent physical disability.
The study found one in 75 of these older Australians carried a pathogenic genetic variation.
Twenty people carried a mutation for Lynch syndrome, 13 people had the mutation for familial high cholesterol, 15 women had the BRCA1/BRCA2 mutations and there were 86 carriers of genes associated with inherited cardiac disorders.
"It is important because the big question in genetics is why are they unaffected for their whole life?" Dr Lacaze said.
"It's possible that they're carrying protective factors that are offsetting their risk, protective genetic factors," he said.
The next stage of his research is trying to find those protective factors.
Dr Lacaze last year proposed a radical plan to provide free genetic testing for all Australians aged 18-25 to prevent thousands of cancer cases a year.
He desperately needs funding to trial the program in 10,000 young Australians.
Originally published as Cancer genes are 'not a death sentence'