Less-Frequent Prostate Tests Suggested Another Study Indicates Men May Need Biopsies Following Psa Cancer Screening
Many men who now get a common prostate-cancer screening test annually may be able to take the test every two years instead, but others may need to have biopsies following the test to check for prostate cancer, according to studies published today.
The two studies, in the Journal of the American Medical Association, recommend new ways of reading results from the PSA test, which stands for prostate-specific antigen. Along with a doctor’s digital examination of the size and shape of the gland, the test is a primary way of checking for the cancer.
Standard American medical practice has been that men whose PSA counts register lower than 4, and whose rectal exams suggest nothing amiss, do not need to have a biopsy to check for cancer.
But researchers from Washington University School of Medicine in St. Louis said this rule may miss a significant number of cases of prostate cancer.
A team led by Dr. William Catalona, the school’s urologic surgery chief, found that 22 percent of men they studied who had counts between 2.6 and 4 had prostate cancer, and 83 percent of those were “medically important” cases that would warrant immediate treatment.
A second study in the journal, by Johns Hopkins researchers, found that men whose PSA counts are under 2.0 can safely have PSA tests administered every other year instead of annually. This would save millions of dollars and halve testing for as many as 70 percent of men aged 50 to 70.
“Our results suggest that annual testing for PSA in all men is not a cost-effective way to catch prostate cancer at an early, treatable stage,” said Dr. H. Ballentine Carter, associate professor of urology at the Johns Hopkins Brady Urological Institute.
The reason is that a man whose count is under 2.0 is quite unlikely to develop incurable prostate cancer before two years go by, Carter said. “We can eliminate a lot of unnecessary testing,” Carter said.
Prostate cancer screening standards have been subject to considerable debate and scrutiny because millions of older men develop prostate cancer, but typically it is slow-growing and they die of something else before needing treatment.
About 40,000 US men died of prostate cancer last year, and more than 315,000 new cases were diagnosed during the year, according to government figures. But while about 3 in 10 men get prostate cancer, only about 3 in 100 men over 50 die of it.
Dr. Jerome P. Richie, chief of urology at Brigham and Women’s Hospital and the Elliott C. Cutler professor of medicine at Harvard Medical School, said Tuesday he thinks the recommendation to reduce PSA testing for men with counts under 2.0 is “a reasonable and responsible approach.” But he said the Washington University recommendation to lower the threshold for biopsies could lead to numerous needless, expensive procedures.
Typically the biopsy requires the patient to have sonogram probes and biopsy needles inserted in his rectum for 15 to 20 minutes.
Though the PSA tests can catch cancer early, they register many false positives. As many as two out of three men whose PSA counts are between 4 and 10, often leading to uncomfortable biopsies, turn out not to have cancer, Richie said.
Washington University’s Catalona said needless biopsies can be reduced somewhat in men with PSA counts over 2.6 if their doctors also measure the percentage of PSA in their blood that is “free PSA” not attached to a protein.
If doctors limit biopsies to men whose free PSA is 27 percent or lower, they can reduce needless biopsies 20 percent, he said.