Cut Off Point of Percentage of Free PSA that Optimize for Prostate Cancer Detection
Keywords:
Prostate cancer, PSA, Free PSA, Percent-free PSAAbstract
The purpose of this study was to determine the cut off point of percentage of free PSA that optimizes for prostate cancer detection in Thai men with PSA level between 4-10 ng/ml.
The study included 118 Thai men with PSA level between 4-10 ng/ml tested for free PSA at Phramongkutklao Hospital between 2002 to 2004 and then calculated for percentage of free PSA. Prostate glands were biopsied by transrectal ultrasound (TRUSBX) guidance, the cut off points percentage of free PSA were evaluated.
The specificity of cut off points of percentage of free PSA according to 10, 15, 18, 19, 20, 21, 22 and 25 were 76.92%, 48.94%, 37.14%, 32.5%, 29.55%, 27.84%, 26.92% and 27.03%, respec- tively and the sensitivity of cut off points of percentage of free PSA according to 10, 15, 18, 19, 20, 21, 22 and 25 were 33.33%, 76.67%, 86.67%, 86.67%, 86.67%, 90%, 93.33% and 100%, respec- tively.
In this study, the highest specificity and the highest sensitivity were the cut off points of percentage of free PSA at 18 so this point must be optimal for prostate cancer detection in group of PSA 4-10 ng/ml.
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