Abiraterone, an experimental cancer drug under trial, has potential for shrinking prostate tumors at a fast rate and giving cancer patients double the chance of survival in 70 to 80 percent of patients with aggressive cancers.

The study has a small trial sample of 21 patients, although the medication was first tested in over 250 men with similar positive results.

Cancer and urology experts agree Abiraterone holds promise.

"There is a general sense in the prostate cancer community that this agent is extremely promising and is very likely to have an important role n the management of prostate cancer patients," said Dr. Howard Sandler, a radiation oncologist. Dr. Robert Reiter, a urologist at UCLA's Jonsson Comprehensive Cancer Center, told the Los Angeles Times, "It's pretty safe to say that we are going to have a lot more to offer patients when this drug gets approved."

Cougar Biotechnology of Los Angeles sponsored the trials. It could benefit the 28,000 men diagnosed each year with prostate cancer when it becomes available in the market by 2011.

The results of the study were published in the Journal of Clinical Oncology.