A scientific mega-collaboration to learn more about what leads to cancer has uncovered dozens of DNA markers that can help reveal further a person’s risk for breast, ovarian or prostate cancer.  A huge international effort involved more than 100 institutions and genetic tests on 200,000 people.  And while the headway seems significant in many ways, the potential payoff for ordinary people is mostly this:  Someday there may be genetic tests that help identify women with the most to gain from mammograms, and men who could benefit most from PSA tests and prostate biopsies.  Perhaps further in the future these genetic clues might lead to new treatments.

One analysis suggests that among men whose family history gives them roughly a 20 percent lifetime risk for prostate cancer, such genetic markers could identify those whose real risk is 60 per cent.  The markers also could make a difference for women with BRCA mutations, which puts them at high risk for breast cancer.  Researchers may be able to separate those whose lifetime risk exceeds 80 per cent from women whose risk is about 20 to 50 per cent.  One doctor said that might mean  some women would choose to monitor for cancer rather than taking the drastic step of having healthy breasts removed.

“This adds another piece to the puzzle,” said Harpal Kumar, chief executive of Cancer Research U.K., the charity which funded much of the research.  Experts not connected with the work say it is encouraging but that more research is needed to see how useful it would be for guiding patient care.

(with contributions by The Associated Press)