These results were presented today at ASTRO's 45th annual meeting in Salt Lake City, Utah, by Eric M. Horwitz, M.D., radiation oncologist at Fox Chase Cancer Center and lead author of the paper.
Using the largest previously pooled dataset of prostate cancer patients treated with radiation therapy alone, the study examined multiple definitions of biochemical control (success or failure of treatment) to determine more accurate guidelines.
The data set included 4,839 patients from nine institutions treated with radiation therapy alone. The data provided biochemical failure and clinical outcomes using the ASTRO definition.
"We reanalyzed this data to correlate alternate biochemical failure definitions with provided clinical endpoints to see which definitions were the most sensitive and specific," explained Horwitz.
The biochemical failure definitions were examined based on distant failure or on clinical failure as endpoints.
The researchers examined about 100 different definitions to develop a more accurate formula for determining treatment failure. Of the 100, only three provided both specificity and sensitivity for distant failure and clinical failure.
The specificity and sensitivity of the ASTRO definition to predict distant failure were 55 percent and 68 percent, respectively. "Using the three alternate definitions of distant failure, we obtained specificity and sensitivity results of 69 and 73 percent, 76 and 72 percent and 72 and 70 percent, respectively," Horwitz said.
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Contact: Karen Carter Mallet
k_carter@fccc.edu
215-728-2700
Fox Chase Cancer Center
20-Oct-2003