TUESDAY, Oct. 21, 2003 (HealthDayNews) -- The presence of a biomarker called Ki-67 may be a significant predictor of outcome for prostate cancer patients treated with both hormones and radiation, say researchers at Fox Chase Cancer Center in Philadelphia.
When a tumor cell tests positive for Ki-67, which is a proliferation antigen, that means the tumor is actively growing.
Previous smaller studies by the Fox Chase scientists found the greater the proportion of prostate tumor cells with Ki-67, the more aggressive the cancer. Those previous studies involved small patient numbers and didn't conclusively establish the usefulness of the Ki-67 biomarker.
"Our (new) study conclusively shows that Ki-67 was the most significant determinant of distant metastasis and death in prostate cancer patients," Dr. Alan Pollack, chairman of radiation oncology at Fox Chase, says in a prepared statement.
"The relationship of Ki-67 to patient outcome is a continuous function, wherein the higher the per cent of Ki-67, the greater the risk of adverse result. In addition, Ki-67, along with PSA, Gleason score and stage, appears to be valuable in determining whether high-risk patients may be spared long-term androgen deprivation," Pollack says.
The study was presented Oct. 21 at the annual meeting of the American Society for Therapeutic Radiology and Oncology in Salt Lake City.
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