Description: MONDAY, July 9 (HealthDay News) --The experimental drug abiraterone, which prevents testosterone production anywhere in the body, may reduce blood levels of the prostate cancer marker prostate-specific antigen (PSA) by half, new research shows.

The study also found that the drug can shrink tumors in men whose prostate cancer has continued to grow despite treatment.

The British findings were to be reported July 8 at the annual European Society for Medical Oncology meeting in Lugano, Switzerland.

Dr. Alison Reid, from The Institute of Cancer Research, and Dr. Gerhardt Attard, from The Institute and The Royal Marsden NHS Foundation Trust in London, reported on early results from two ongoing phase 2 trials of abiraterone in men with advanced prostate cancer.

Both trials have seen PSA levels reduced by 50 percent. PSA levels are a measure of a protein produced by cells in the prostate. Unusually high levels of the antigen indicate a growth in the prostate.

The men, all of wh