Previous studies have shown that combining three years of androgen suppression therapy (AST) with radiation therapy increased survival rates of patients with localized but more advanced prostate cancer. However, AST use for more than one year has been shown to cause significant side effects, including bone density loss, impaired memory, anemia, breast enlargement, hot flashes and impotence, in some patients especially those who were elderly.
According to the study's lead investigator, Anthony D'Amico, MD, PhD, a radiation oncologist with BWH and DFCI and professor of radiation oncology at Harvard Medical School (HMS), "This is the first study to provide evidence that 3D conformal radiation therapy combined with six months of AST provides a survival benefit for those with early-stage prostate cancer. These results should prompt physicians evaluating treatment options to prescribe six months of hormone therapy as opposed to a three-year regimen. Six months of hormonal therapy now becomes the preferred duration of hormonal therapy if used for patients with localized prostate cancer treated with external beam radiation."
The researchers randomly assigned 206 patients to receive either two months of radiation therapy in conjunction with six months of AST or two months of radiation therapy alone. Patient follow-up averaged four and a half years. The patients treated with the combination therapy had a two-fold reduction in risk of death compared to those treated only with radiation therapy (12 percent compared to 22 percent). They also were less likely to require salvage AST five years following randomization.
"Patients with prostate cancer face a wide variety of decisions regarding their treatment, each with its own distinct benefits and risks," said senior author Philip Kantoff, MD, chief of Solid Tumor Oncology at DFCI and BWH and professor of medicine at HMS. "That six months of hormone therapy combined with radiation therapy is an effective treatment provides patients with an important option if they are concerned about hormone therapy related side effects."
While this study answers an important question about the duration of AST in patients with localized prostate cancer undergoing radiation therapy, Kantoff and D'Amico said the next question is if chemotherapy (Taxotere), in conjunction with AST and radiation therapy, can further improve survival in men with localized but high-risk prostate cancer.
BWH is a 735-bed nonprofit teaching affiliate of Harvard Medical School and a founding member of Partners HealthCare System, an integrated health care delivery network. Internationally recognized as a leading academic health care institution, BWH is committed to excellence in patient care, medical research, and the training and education of health care professionals. The hospital's preeminence in all aspects of clinical care is coupled with its strength in medical research. A leading recipient of research grants from the National Institutes of Health, BWH conducts internationally acclaimed clinical, basic and epidemiological studies.
Dana-Farber Cancer Institute is a principal teaching affiliate of the Harvard Medical School and is among the leading cancer research and care centers in the United States. It is a founding member of the Dana-Farber/Harvard Cancer Center (DF/HCC), designated a comprehensive cancer center by the National Cancer Institute.
Journal
JAMA