Biomarker test may improve prostate cancer diagnosis

A test for the urinary biomarker thymosin beta15 (Tbeta15), in combination with PSA testing, can improve both the sensitivity and specificity of prostate cancer diagnosis, according to a study published in the online edition of Prostate (Jan. 21, 2005).

The study compared Tbeta15 levels in urine samples from 121 men with prostate cancer, 15 men with kidney or bladder cancer, 81 men with non-malignant prostate disease, 73 men with other non-malignant urologic diseases, and 52 healthy men.

Men with prostate cancer were 12 times as likely to have elevated Tbeta15 levels as healthy men, according to the researchers, led by Bruce Zetter, PhD, of Children's Hospital Boston. In addition, Tbeta15 levels in men with prostate cancer were significantly higher than those of men with other genitourinary diseases.

Nearly half of cancer patients whose PSA levels were considered normal tested positive for Tbeta15, while many men with genitourinary diseases had elevated PSAs but normal Tbeta15 values, the authors said.