Researchers have identified over 80 regions of the human genome that, when found in an individual, can increase the risk of certain kinds of cancer, including breast cancer.

As the largest study ever of its kind, scientists studied the DNA make-up of 200,000 people - half with cancer and the other half without. In doing so, they located variations in those struggling with prostrate, breast and ovarian cancers.

According to a press release issued by Cancer Research UK, one of the study's funders, each of these alterations, called Single Nucleotide Polymorphisms (SNP), only raise the risk of cancer by a small amount; however, the 1 percent of the world's popuation that host many SNPs could be as much as 50 percent more likely to develop prostate cancer and 30 percent more likely to develop breast cancer.

And while the team isn't announcing any miracle drug, they are hopeful that the massive study may lead to significant progress in detecting the disease.

"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 cancers and then targeting screening tests to these individuals," said Doug East, the study author and cancer Research UK scientist at the University of Cambridge.

Eventually, researchers believe that a simple blood test could reveal what cancers a person has a genetic predisposition for, if any. 

The study further revealed 23 new genetic variations that may lead to prostate cancer, 49 for breast cancer and 11 for ovarian cancer.

In addition to looking for variations, researchers looked for the SNPs that may influence different breast cancers to behave differently as well as regions that many influence the cancer risk for people with faults in the BRCA genes - a group known to be at greater risk for both breast and ovarian cancers.

In doing so, scientists discovered that women who have a BRCA1 fault as well as most of the genetic variants linked to BRCA1 have more than an 80 percent chance of developing breast cancer by the time they turn 80. For women with the BRCA1 fault and just a few alterations, this number drops to 50 percent.

Finally, researchers involved in the study identified a series of SNPs only associated with an especially aggressive type of breast cancer, which in turn may lead the way for new treatments.

"This groundbreaking international work highlights how complext cancer is," said Harpal Kumar, Cancer Research UK's chief executive. "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 a 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 in its earliest stages."