PHILADELPHIA (October 23, 2000) -- A Phase III trial examining the use of long-term hormone suppression with radiation in locally advanced prostate cancer shows that the treatment can prevent recurrence and improve survival.
The study by the Radiation Therapy Oncology Group is the largest phase III prostate radiation treatment trial to date. It was presented at the American Society for Therapeutic Radiology and Oncology Annual Meeting in Boston, Mass. during a plenary session by Gerald E. Hanks, M.D., chairman of radiation oncology at Fox Chase Cancer Center, Philadelphia, Pa.
The study is a prospective randomized trial of optimal duration of androgen suppression and external beam radiation in patients with locally advanced prostate cancer. All patients received four months of the drugs Zoladex and Flutamide, two months before and two months during radiation.
These drugs suppress production and utilization of the hormone androgen, which is known to spur the growth and spread of prostate cancer. The patients were then randomized to receive either no further therapy or 24 months of additional Zoladex alone. The 1,520 patients who participated in the study were followed for an average of 4.8 years.
The group with long-term androgen deprivation (LTAD) did significantly better than did those receiving short-term hormone treatment in many indicators: disease-free survival (54% vs. 34%), local progression (6% vs. 13%), and freedom from distant metastasis (16% vs. 10%). Sixty-one patients died of prostate cancer in the short-term androgen deprivation group compared to 36 in the LTAD group.
"Our results set a new standard of treatment for patients with advanced localized prostate cancer," said Hanks, chairman of the multi-center study. "In addition to controlling recurrence, the use of long-term androgen suppression in this study demonstrated a reduction of death due to prostate cancer in favor of the LTAD group."
Patients at highest risk of relapse (those with tumors rated "Gleason score" 8-10) treated with LTAD had significantly better five-year survival (80% vs. 69%) and fewer deaths from prostate cancer (10% vs. 22%) than compared to those who had short-term therapy. In these high-risk patients, 12 LTAD patients died from prostate cancer compared with 29 in the short-term group.
Fox Chase Cancer Center, one of the nation's first comprehensive cancer centers designated by the National Cancer Institute in 1974, conducts basic and clinical research; programs of prevention, detection and treatment of cancer; and community outreach. For more information about Fox Chase activities, visit the Center's web site at: Fox Chase Cancer Center
Abstract #4 RTOG Protocol 92-02: A Phase III Trial of the Use of Long Term Total Androgen Suppression Following Neoadjuvant Hormonal Cytoreduction and Radiotherapy in Locally Advanced Carcinoma of the Prostate Presented Oct. 23, 2000, 2:00 p.m., Plenary Session.