The study involved 50 men who had undergone surgery or radiation but quickly experienced increases in prostate-specific antigen or PSA, a biomarker that indicates the presence of cancer. UCLA researchers measured "doubling time," how long it takes for PSA levels to double, a signal that the cancer is progressing, said Dr. Allan Pantuck, an associate professor of urology, a Jonsson Cancer Center researcher and lead author of the study.
Doubling time is crucial in prostate cancer, Pantuck said, because patients who have short doubling times are more likely to die from their cancer. The average doubling time is about 15 months. In the UCLA study, Pantuck and his team observed increases in doubling times from 15 months to 54 months, an almost four-fold increase.
"That's a big increase. I was surprised when I saw such an improvement in PSA numbers," Pantuck said. "In older men 65 to 70 who have been treated for prostate cancer, we can give them pomegranate juice and it may be possible for them to outlive their risk of dying from their cancer. We're hoping we may be able to prevent or delay the need for other therapies usually used in this population such as hormone treatment or chemotherapy, both of which bring with them harmful side effects."
The study appears in the July 1 issue of Clinical Cancer Research, the peer-reviewed journal of the American Association of Cancer Research.
"This is not a cure, but we may be able to change the way prostate cancer grows," Pantuck said. "We don't know yet the specific factors behind this response - that's our next step in this research. We want to find out what cell signaling pathways might be affected, what is happening to keep PSA levels stable."