Scientists say DNA testing could reveal which men are genetically predisposed to aggressive prostate cancers, after a study identified a possible 13 gene defects - present in eight genes - common to several prostate cancer patients.

Testing blood samples from 191 men with prostate cancer, each of whom had at least two relatives that also suffered the disease, researchers found that 21 percent of men who had at least one of the possible mutations developed an advanced case of the disease that metastasized to other areas of the body. Conversely, of the men who didn't carry any mutations, only three percent developed a more advanced case of prostate cancer.

Published in the British Journal of Cancer, results of the study make the crucial connection between certain genetic patterns and the likelihood of developing prostate cancer, as well as potentially identifying how severe the cancer will be. Currently, tests can only identify that tumors are present, rather than discerning whether or not the cancer will spread.

"Our study shows the potential benefit of putting prostate cancer on a par with cancers such as breast cancer when it comes to genetic testing," said the study's co-leader, Professor Rosalind Eeles of the Institute of Cancer Research in London said in a formal statement. "Although ours was a small, first-stage study, we proved that testing for known cancer mutations can pick out men who are destined to have a more aggressive form of prostate cancer. We proved that testing for known cancer mutations can pick out men who are destined to have a more aggressive form of prostate cancer."

Indeed, just as it's possible for women with a family history of breast and ovarian cancers to be screened for the BRCA1 and BRCA2 genes, Dr. Eeles and her team hope that the findings uncovered in their study will enable a similar test to be developed for men with a history of prostate cancer. However, Dr. Eeles did stress the importance of further study to determined whether or not identifying men with the suspicious gene mutations does in fact boost survival rates. "If so, then in the future, genetic testing may be needed as part of the prostate-cancer care pathway," she said.

Presently, prostate cancer is screened by analyzing a protein called prostate specific antigen (PSA), with levels typically rising when prostate cancer is present. Nevertheless, this technique cannot identify at-risk individuals, and findings are not always conclusive.