Researchers at the University of California - San Francisco (UCSF) have suggested that just four months of hormonal therapy could delay prostate cancer growth by up to eight years.
In the study, the researchers found that early short course of hormone treatment given with standard external beam radiation therapy slowed cancer growth by as much as eight years, especially the development of bone metastases, and increased survival in older men with potentially aggressive prostate cancer.
The study also found that the 'neoadjuvant' hormonal therapy did not increase the risk of heart disease, a potential side effect of long-term hormonal therapy.
Hormonal therapy, called androgen deprivation therapy (ADT), prevents the male hormone testosterone fuelling pro-state cancer. Usually they are only given when surgery and radiation treatment have failed to work.
"This study demonstrates that the benefits of short-term hormonal therapy for men receiving radiation therapy for prostate cancer far outweigh the risks," said lead author Mack Roach III, MD, professor and chair of radiation oncology and professor of urology at the University of California, San Francisco.
"While four months of hormonal therapy isn't enough to cause significant side effects, we found that it can delay the development of bone metastasis by as many as eight years, which is very significant," he added.
Researchers examined 224 men with high-risk prostate cancer who received ADT (goserelin and flutamide) before and concurrent with external beam radiation therapy, and 232 men with the disease who received radiation therapy alone.
After 13 years of follow up, they found that prostate cancer death rates at ten years were 23 per cent for men who received ADT plus radiation compared to 36 per cent, who received the radiotherapy.
Disease metastasis rates were 35 versus 47 percent, disease-free survival were 11 percent versus 3 percent and biochemical failure rates were 65 percent versus 80 percent.
In 40 per cent of trial patients, who underwent 'neoadjuvant' hormonal therapy, there was a delay of up to eight years in the time it took for cancer to spread to their bones.
It was also found that fatal cardiac events occurred in 12 percent of patients in the ADT group compared with 9 percent of the radiation-only group, a difference that was not statistically significant.
"So by taking a little bit of hormonal therapy early, patients may avoid having to take a lot of it later," added Dr. Roach.
The study is being published online January 2 in the Journal of Clinical Oncology (JCO).