Researchers made a new study which suggests hormone suppression therapy could increase substantially an advanced prostate cancer patient's chances of living free of the disease.Michel Bolla, a professor at Grenoble University Hospital, examined the potential benefits of suppressing the male hormone androgen, similar to the more commonly known male hormone testosterone, among 400 patients in advanced stages of their prostate cancer, meaning their chances of survival were deteriorating. The international study involved patients throughout Europe as well as in Canada and Israel.
In the study, the men were randomly assigned to receive either radiation therapy alone or androgen suppression given during and after radiotherapy for three years. The average follow-up period was five and a half years.
Study results revealed almost three-quarters of the men who received the combination therapy, or 70 percent, had an increased five-year, disease-free survival rate compared to only 30 percent of patients who received only radiotherapy. Overall, survival rates were 80 percent within the hormone-suppression group and 62 percent for the radiotherapy group.
Bolla felt that at the present time a long-term hormone therapy 2 or 3 years compared to short-term resulted in statistically significant improvements in overall survival, as shown by this trial. The long-term survival rate for men with aggressive prostate cancer is poor, so additional therapies are needed to improve their chances. He added the findings also indicate hormone suppression with radiotherapy or external irradiation could trigger apoptosis -- the cancer cells destroying themselves.
However, there were side effects, Bolla said, including hot flashes, loss of libido and impotency. Kenneth Koeneman, urology professor at University of Texas Southwestern Medical Center at Dallas, said the side effects go beyond sexual dysfunction. "It's systemic castration," Koeneman told UPI. Hormone suppression also cab cause breast enlargement, a drop in muscle mass and an increase in body fat, he said. Prostate cancer patients on this particular therapy also are vulnerable to osteoporosis.
Hormone suppression is used in the United States, "but not necessarily for three years," he said. The reason it is used cautiously is "taking away the male hormone actually affects the marker we use" to detect cancer levels, Koeneman explained. That marker is called prostate-specific antigen or PSA, which is hormone-dependent. Hormone suppression may lower PSA levels suggesting the prostate cancer has been cut back, which might be an incorrect assumption.
"We may just be fooling ourselves that the cancer is not there," Koeneman said. He also questioned Bolla's assertion androgen suppression could contribute to cancer cell death. "Androgen suppression in the history of man has never cured anybody that we know of."
Dr. Rowan Chlebowski, chief of medical oncology at the Harbor-UCLA Research Education Institute in Los Angeles, said doctors sometimes walk a tightrope between the potential benefits and downsides of hormone therapy.