Peek Into Future of Prostate Cancer
Prostate Cancer Vaccine, Better Tests May Be Just Over the Horizon
Don't Watch and Wait -- Vaccinate continued...
Kast says his team could produce a human vaccine in about two years. Any actual vaccine treatment would need years of testing before it became available, notes Durado Brooks, MD, MPH, director of prostate and colorectal cancers for the American Cancer Society, Atlanta.
"I would hesitate to get too excited about this vaccine study, since we are at this point we are talking about mice -- and the jump from mice to men is usually many years in the making," Brooks tells WebMD. "It certainly does open the door to some potentially exciting avenues, but we are not right around the corner from being able to duplicate these results in human populations."
Better Prostate Cancer Test?
A major problem with the PSA prostate cancer screening test is that it looks for only one prostate-specific protein, notes Arul M. Chinnaiyan, MD, PhD, professor of pathology and urology at the University of Michigan.
Chinnaiyan's team is therefore looking at what they call a "multiplex" test that will look for a number of prostate cancer markers. In their current study, they have looked at four such markers in the urine of 234 men whose high PSA levels caused them to have prostate biopsies.
The new test wasn't perfect. But it identified 80% of the men who turned out to have prostate cancer. And it was able to rule out prostate cancer in 61% of the men whose biopsies were negative.
"Before biopsy, this test is identifying prostate cancer better than the PSA test," Chinnaiyan tells WebMD. "The idea is that a patient would come in with an elevated PSA score, and we would be able to give him this second test. Ideally, it would be a multiplex test with a variety of prostate cancer markers. We are going to go away from single markers to multiple markers in the near future."
The American Cancer Society's Brooks notes that the new test doesn't address the biggest problem for prostate cancer screening.
"Just finding more cancers is not necessarily a good thing," Brooks says. "All prostate cancers are not created equal. What we need is a better tool to identify those cancers that are more likely to be aggressive and result in a benefit if identified patients are treated."
Chinnaiyan admits that the new test, in its current form, cannot do this. But he notes that one of the markers used in the test is a "gene fusion" marker of more aggressive cancers. By finding and using more such markers, he says, the test may one day predict the aggressiveness of a man's prostate cancer.
"But we want to take baby steps and tackle the diagnostic aspects of the test first," Chinnaiyan says.