It is being described as the single biggest leap forward in understanding the genetics of disease.
"So far there is some evidence of aspects of genetic discrimination and employment in the US .... In the first instance this kind of genetic testing is likely to be abused with people who probably got some family history anyway also existing illness, and certainly my experience of working on the issue of discrimination over the past 10-15 years has been the people who actually lose out most in areas of employment or insurance of various kinds, are the people who are already ill, or who have a strong family history of illness, and genetic testing doesn’t really make much difference to that scenario."
- John Gillot from the Economic and Social Research Council
Scientist says they have isolated parts of the human DNA that can identify those most likely to develop breast, ovarian and prostate cancer.
A huge international effort, led by British researchers, carried out genetic tests on 200,000 people.
Researchers compared the genetic code of thousands of healthy men and women, with thousands more who had developed the cancers.
Those who had had the cancers were found to have faults in particular parts of their DNA, those with the most faults were the most at risk.
In the case of prostate cancer, those most at risk were five times more likely to develop the disease, and had 50-50 chance of doing so.
For one type of breast cancer, women with the most faulty DNA were three times more likely to get the cancer, and one-third of them did.
The discovery could see the development of personalised risk profiles for the diseases, and targeted screening programmes for those most at risk.
But there are warnings the same DNA information could be used by health insurers or employers, to screen out people, based on their genetic predispostion for developing a particular illness.
So what are the implications for privacy, discrimination, and individual rights?
To discuss this, Inside Story is joined by guests: Julie Sharp, a senior science information officer at Cancer Research UK; and John Gillot from the Economic and Social Research Council.
"I think it is a really important step forward. It's the biggest study of its kind, and it gives us wealth of information that we can actually start to use immediately. It's really important to note that actually one of the first applications of this information will be those people who already have some kind of family history of cancer, and it's those people where we really might start to apply this work first of all, before we start looking at the wider population .... In the long term these kind of test might help us to make things like screening more efficient, because if we find someone at a very low risk then they might no need screening as often, if they are at high risk then they need more intensive treatment and screening. It's really important to note that these tests wouldn't just be used in isolation, so in the same way that the doctor takes account of someone's life style , the family history, as well as the genetics, all these things will be added together so that doctors could really help and advise people with a greater degree of information, that will really help them to make those big decisions."
Julie Sharp, a senior science information officer at Cancer Research UK