Biomarker may help early detection of prostate cancer

A protein in the blood may prove to be a biomarker that is more sensitive and specific than PSA and digital rectal exam, according to scientists at Panacea Pharmaceuticals, Inc., Gaithersburg, MD. If they’re right, the protein, an enzyme called human aspartyl (asparaginyl) beta-hydroxylase (HAAH), could ultimately help reduce the number of unnecessary biopsies and may identify prostate cancer at an earlier stage.

“Currently, if an individual has a high PSA and a positive DRE, the recommendation is that he have a biopsy of the prostate, and more often than not-by some estimates, as much as 80% of the time-there will not be evidence of cancer,” said Stephen Keith, MD, MSPH, of Panacea.

To find a more accurate way to detect prostate cancer, researchers at Panacea developed a test in which they could detect HAAH in blood serum. They compared HAAH levels in the blood of 16 individuals with prostate cancer to that of 23 healthy individuals. Those with prostate cancer showed high HAAH levels, whereas none of the normal control individuals did, the researchers reported at the American Association for Cancer Research’s Molecular Diagnostics in Cancer Therapeutic Development meeting in Chicago.

“We hope our HAAH blood test, combined with PSA and DRE, will increase the sensitivity and specificity of screening for prostate cancer,” Dr. Keith said. “Those without cancer can avoid unnecessary biopsies through the use of all three screening tests.”

Panacea scientists are planning clinical trials with prostate tissue samples from 800 patients.