Researchers at the University of Cambridge and Institute of Cancer Research studied the DNA of more than 200,000 people to investigate inherited risk of the disease. They found more than 80 genetic regions that were linked to the three hormone-related cancers.
The results could lead to improved screening for cancer to assess an individual's level of risk. Identifying high-risk people earlier on means that they can receive preventative treatments or be monitored regularly to ensure the disease is picked up when treatable.
Professor Doug Easton, a Cancer Research UK scientist at the University of Cambridge, said: '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'.
The scientists found that those with genetic variations known as single nucleotide polymorphisms (SNPs) in these areas are at a higher risk of developing cancer. Their findings showed that each SNP increases the risk by a small amount, and the more SNPs a person has, the greater their chance of developing cancer.
Screening for these SNPs will also identify people who are at a lower than average risk, which could prevent distress and harm caused by unnecessary treatment of false positives and reduce screening costs.
The researchers uncovered 49 SNPs related to breast cancer alone, which doubled the number of previously known variants. They also looked for SNPs that affected the behaviour of different types of breast cancer. Women with a gene fault known as BRCA1 were found to be more likely to develop the disease if they had many of these SNPs.
'By looking for people who carry most of these variations we will be able to identify those who are at the greatest risk of getting these cancers and then targeting screening tests to these individuals', said Professor Easton.
Many of the SNPs identified were near to areas of the genome that control how certain genes behave. Genetic variation in these areas could lead to cells growing out of control or allow cancer cells to spread throughout the body. The researchers hope that by understanding how these genes work, they will gain an insight into how cancers develop and how to treat them.
The main results were published in five papers in Nature Genetics.