Research by Cambridge scientists could lead to routine tests for patients genetic risk of cancer within five years.
The study compared the DNA of more than 100,000 cancer patients with a similarly sized sample from the general population.
They used microchip technology capable of identifying more than 200,000 genetic variants, some of which were suspected of being linked to cancer.
More than 1,000 scientists from 130 institutions in Europe and the US took part in the Collaborative Oncological Gene-environment Study (Cogs).
We're on the verge of being able to use our knowledge of these genetic variations to develop tests that could complement breast cancer screening and take us a step closer to having an effective prostate cancer screening programme
Dr Harpal Kumar, chief executive of Cancer Research UK, which co-funded the research, said:
This groundbreaking international work highlights how complex cancer is.
Hundreds, if not thousands of genes are likely to play a role in how cancers start.
But by understanding why some people seem to be at greater risk of developing cancer we can look towards an era where we can identify them and take steps to reduce their chances of getting cancer or pick up the disease at its earliest stages."
More top news
Seven Ukrainian men have been arrested after a boat containing suspected illegal immigrants ran ashore in high winds off the Suffolk coast
Cloudy with outbreaks of rain, mainly easing by dawn and lows of 7 deg C (45 deg F) overnight
The RSPCA's warning people about disposing of fishing litter correctly after a swan was found with a fishing hook through its tongue.