Two studies yield new hope for prostate cancer patients

For more than 186,000 men in the United States diagnosed with prostate cancer each year, there is hope on the horizon. An experimental drug therapy seems to have helped inoperable prostate cancer in two patients who participated in a clinical trial conducted by the Mayo Clinic.

The men were given Medarex's experimental drug, ipilimumab, a specially engineered antibody that boosts the immune system's ability to fight cancer. The drug, in combination with standard hormone and radiation treatments, helped eliminate the aggressive tumors, which had already spread into their abdominal areas. Both patients are now considered cancer-free. "The goal of the study was to see if we could modestly improve upon current treatments for advanced prostate cancer," explains urologist and immunologist Dr. Eugene Kwon. "The candidates for this study were people who didn't have a lot of other options. However, we were startled to see responses that far exceeded any of our expectations."

Ipilimumab is an antibody that appears to accelerate the ability of the hormone therapy androgen ablation to kill cancer. Androgen ablation helps shrink tumors by ridding the body of testosterone, which is known to fuel cancer. The patients showed steady decreases in their prostate-specific antigen (PSA) counts, a test used to detect prostate cancer.

Before undergoing the experimental treatment, they were considered "inoperable." Following the treatment, they were deemed eligible for surgery. "The tumors had shrunk dramatically," says co-investigator Dr. Michael Blute, the Mayo urologist and surgeon who operated on both patients. "I had never seen anything like this before. I had a hard time finding the cancer. At one point, the pathologist, who was working during surgery, asked if we were sending him samples from the same patient."

In other encouraging news, a small study was conducted by researchers from Louisiana State University in which 26 men with prostate cancer were given a concentrated extract of tea polyphenols for an average of 34 days. They found that the participants experienced a significant reduction in the levels of several growth factors that promote cancer, as well as reductions in their PSA levels. Each of the men took four capsules a day totaling 800 milligrams of the green tea extract EGCG. "There is reasonably good evidence that many cancers are preventable, and our studies using plant-derived substances support the idea that plant compounds found in a healthy diet can play a role in preventing cancer development and progression," says study lead author James Cardelli. The study is published online in the journal Cancer Prevention Research.

News Release: Promising therapy for prostate cancer www.bio-medicine.org  June 22, 2009

News Release: Green tea may slow prostate cancer  www.latimes.com   June 22, 2009