Hopkins Researchers Find Better Blood Test for Prostate Cancer
|New studies of a blood protein recently identified at
Johns Hopkins, early prostate cancer antigen-2 (EPCA-2), may change the
way men are screened for prostate cancer — a disease that kills tens of
thousands of men every year.
Results showed that the EPCA-2 test was negative in 97
percent of the patients who did not have prostate cancer. Men with no
evidence of disease (regardless of their PSA levels), as well as the
control group of patients with other cancer types and benign conditions,
all had EPCA-2 levels below the cutoff.
In contrast, in a multi-institutional study published in
2003 in the Journal of Urology, PSA levels between 4 and 10 nanograms per
milliliter were shown to be accurate in identifying patients without
prostate cancer only 19 percent of the time.
In addition, 77 percent of the BPH patients had a level of
EPCA-2 lower than the cutoff point. Getzenberg says this is well within
the likely percentage range of BPH patients who are prostate-cancer free.
He says this result was encouraging since BPH is often associated with
elevated PSA levels, leading to misdiagnosis and unnecessary biopsies.
When it came to correctly identifying patients with
prostate cancer, EPCA-2 levels at or above the cutoff were detected in 90
percent of the men with organ-confined prostate cancer and 98 percent of
the men with disease outside of the prostate. Overall, in this study, the
EPCA-2 test detected 94 percent of the men with prostate cancer.
I have currently been using a test called pca3 Plus, which is a urine test done after a rectal exam to help determine if I should perform a biopsy. If this test is as good as it sounds, it will likely replace PSA. I look forward to seeing how the studies come out.