Two companies have developed genetic tests that eventually could help doctors better predict which prostate cancer patients have serious cases that need aggressive treatment, U.S. researchers reported Wednesday.
One test, developed by San Diego-based Illumina Inc., was designed to help physicians tell which patients considered at medium risk will have their cancer recur after the prostate is removed. Those patients typically have a score of six or seven on the 10-point Gleason scale that is among the standard tests for prostate cancer.
Researchers used the Illumina test to analyze prostate cancer tissue samples for 16 genes and studied how patients fared. They said they could use the information to give patients a score indicating whether they were likely to experience a recurrence of cancer within the next five years.
If confirmed in future studies, “this information could be used to make the next leap as to what (treatment) a patient should or should not have,” said Dr. Tracy Downs, a urologic oncologist at the University of California at San Diego.
Another test developed by Berlin-based Epigenomics AG detected a gene called PITX2 and its “methylation,” a chemical alteration that controls how active a gene is. The PITX2 gene is thought to play a role in regulating hormones, which can fuel cancer growth.
Men whose tissue samples tested positive on the Epigenomics test were three times more likely to experience cancer recurrence after having their prostate removed, researchers said.
“Those are the people that are really possibly good candidates for early (post-surgical) therapy,” said Susan Cottrell, a senior scientist at Epigenomics’s Seattle-based U.S. unit.
The company plans to seek Food and Drug Administration approval of the test if its effectiveness is confirmed in a larger study, Cottrell said. The test could be available for use in patients “in another couple years,” she added.
Findings on both tests were released at a meeting of the American Association for Cancer Research.
Neither test was designed to replace the Gleason score or the PSA test that doctors typically use to determine the severity of prostate cancer, the researchers said.
Prostate cancer is the most common cancer in U.S. men. It is diagnosed in 232,000 men every year and kills up to 30,000 of them. Worldwide, 221,000 men die from prostate cancer each year.