Fox Chase Cancer Center Study: Low Levels of Oxygen in Prostate Cancer Cells Predictor for Treatment Failure
PHILADELPHIA (November 7, 2001) -- A new study demonstrates that the amount of oxygen in prostate cancer cells can predict treatment failure after radiation therapy. The study will be presented by Benjamin Movsas, M.D., vice chairman of the Radiation Oncology Department at Fox Chase Cancer Center, Philadelphia, Pa., at the American Society for Therapeutic Radiology and Oncology Annual Meeting in San Francisco, Ca. on Tuesday, November 6 at 2:25 p.m. PT.
"We have previously demonstrated that low levels of oxygen, or hypoxia, exists in human prostate cancer," explains Movsas. "Hypoxia in tumor cells has been shown to correlate with poor response to radiotherapy and also tumor aggressiveness. In this study, we investigated whether low oxygen levels in prostate cancer patients can predict treatment failure after radiation."
For the study, researchers used custom-made Eppendorf microelectrodes to obtain approximately 100 oxygen readings from both the pathologically involved region of the prostate (as determined by biopsies) and normal muscle (as an internal control) in each patient. Patients in the study had localized disease, pre-treatment PSA, central pathologic review, and a signed Institutional Review Board consent form.
Fifty-seven (57) patients were prospectively studied; all received brachytherapy implants. Nine (9) patients had received prior hormonal therapy. Biochemical failure was defined as 2 consecutive rises in PSA, without a return to baseline.
With a median followup of 18 months (4-31), 9 patients developed biochemical failure.
"The ratio comparing the oxygen in the prostate to the oxygen in the muscle is the strongest predictor for biochemical failure after radiation treatment," explained Movsas. "Patients with very low "hypoxic" ratios (<0.05) had tumor disease control rates at two years of only 31% versus 92% in patients with higher oxygen ratios. We plan to continue to follow patients to further confirm the results of this study. This study has important implications for the advent of novel hypoxic strategies, such as anti-angiogenesis therapies."
Other authors on the study include J.D. Chapman, A.L. Hanlon, E.M. Horwitz, R. Greenberg, C. Stobbe, and G.E. Hanks (retired) all of Fox Chase Cancer Center.
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 www.fccc.edu.
Fox Chase Cancer Center, part of the 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 was also among the first institutions to be designated a National Cancer Institute Comprehensive Cancer Center in 1974. Fox Chase researchers have won the highest awards in their fields, including two Nobel Prizes. Fox Chase physicians are also routinely recognized in national rankings, and the Center’s nursing program has received the Magnet recognition for excellence four consecutive times. Today, Fox Chase conducts a broad array of nationally competitive basic, translational, and clinical research, with special programs in cancer prevention, detection, survivorship, and community outreach. For more information, call 1-888-FOX CHASE or (1-888-369-2427).