Current Guidelines for Assessing Treatment Outcome Following Radiation Therapy Overestimate Progression When Hormones Are Included in Treatment
SALT LAKE CITY, UTAH (October 20, 2003) — A new study from Fox Chase Cancer Center, Philadelphia, Pa., demonstrates that the current guidelines for assessing treatment outcome following radiation therapy overestimates progression when hormone therapy is added. The study results were presented today by Mark Buyyounouski, MD, a resident in Fox Chase Cancer Center's department of radiation oncology, at the 45th annual meeting of the American Society for Therapeutic Radiology and Oncology (ASTRO) in Salt Lake City, Utah.
Hormone therapy, or androgen deprivation, is commonly combined with radiation therapy to treat prostate cancer patients who have an intermediate or high risk of recurrence. Biochemical failure, or disease progression evidenced only by an elevated or rising PSA, is a useful early measure of prostate cancer treatment outcome for physicians. The ASTRO consensus definition of biochemical failure was tested in this study to determine its usefulness following the combined treatment regimen.
"Biochemical failure is declared, meaning there is high probability of future rises in PSA, if a patient has three consecutive rises in post-treatment PSA levels following treatment," explained Buyyounouski. "Upon the completion of hormone therapy, PSA levels rise modestly. However, not all patients will experience continued rises in the years following treatment. Approximately 20 to 30 percent will have three consecutive rises constituting biochemical failure but will not experience continued rises in later years following radiation therapy with androgen deprivation.
"Additional study is required to determine the ideal definition of biochemical failure that most accurately predicts for future progression of disease. Hopefully, improvements in the definition of biochemical failure will further aid physicians is counseling patients about selecting the most appropriate treatment."
Other study authors include Alexandra L. Hanlon, PhD, and Alan Pollack, MD, PhD, of Fox Chase Cancer Center's department of radiation oncology.
Fox Chase Cancer Center, part of Temple University Health System, is one of the leading cancer research and treatment centers in the United States. Founded in 1904 in Philadelphia as one of the nation’s first cancer hospitals, Fox Chase also was among the first institutions to receive the National Cancer Institute’s prestigious comprehensive cancer center designation in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are routinely recognized in national rankings, and the Center’s nursing program has achieved Magnet status for excellence three consecutive times. Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research and oversees programs in cancer prevention, detection, survivorship, and community outreach. For more information, call 1-888-FOX-CHASE (1-888-369-2427).