CHICAGO—Four months of total androgen suppression therapy prior to and during radiation therapy may significantly improve overall survival in patients with intermediate-risk localized prostate cancer compared to radiation alone, data suggest.
“The study provides strong scientific evidence that shows us when to deliver hormone therapy with radiation in patients with localized prostate cancer,” said study co-author Christopher Jones, MD, a radiation oncologist at Radiological Associates of Sacramento, Sacramento, Calif.
“Our findings show that men with low-risk disease, which is the vast majority of prostate cancer patients, have little to gain from adding hormone therapy to radiation. However, men with intermediate-risk disease, which is a significant minority of patients, gain a benefit in overall survival for the addition of only four months of hormone therapy. Prior to this trial, it was unclear whether or not combining hormone therapy with radiation improved survival for these men.”
Dr. Jones and his colleagues studied at 1,979 patients (median age 71 years, 76% white, 20% black, and 4% other races) with low- and intermediate-risk prostate cancer confined to the prostate. They had a PSA level of 20 ng/mL or less. A total of 946 patients (49%) had T1 tumors and 1,015 (51%) had T2 tumors.
Investigators randomized patients to receive total androgen deprivation therapy two months prior to and two months during radiation treatment, or radiation alone. The radiation treatment involved lower doses of radiation than are used with newer techniques, such as intensity-modulated radiation therapy.
The estimated overall survival at 12 years was 51% in the group receiving hormone therapy and radiation compared with 46% of subjects receiving radiation alone, according to findings reported at the American Society for Radiation Oncology annual meeting.
Nearly all of the survival benefit was in the intermediate-risk group. Disease-free survival, freedom from biochemical failure, and positive two-year biopsy rates were also better in the patients who received the combination treatment. Additionally, both treatment arms had similar rates of acute- and late-radiation toxicity.
“We knew that high-risk patients benefited from androgen deprivation therapy, so it was thought that lower risk patients might also benefit,” Dr. Jones told Renal & Urology News. “Now, we know that men with low-risk disease don’t need it but those with intermediate-risk disease, if they are getting low or moderate doses of radiation, will benefit.”