TAILIEUCHUNG - Chapter 091. Benign and Malignant Diseases of the Prostate (Part 3)

The PSA criteria used to recommend a diagnostic prostate biopsy have evolved over time. The goal is to increase the sensitivity of the test for younger men more likely to die of the disease and to reduce the frequency of detecting cancers of low malignant potential in elderly men more likely to die of other causes. Age-specific reference ranges reduce the upper limit of normal for younger men and increase it for older men. Different thresholds alter the sensitivity and specificity of detection. The threshold for performance of a biopsy was ng/mL, which has been reduced to . | Chapter 091. Benign and Malignant Diseases of the Prostate Part 3 The PSA criteria used to recommend a diagnostic prostate biopsy have evolved over time. The goal is to increase the sensitivity of the test for younger men more likely to die of the disease and to reduce the frequency of detecting cancers of low malignant potential in elderly men more likely to die of other causes. Age-specific reference ranges reduce the upper limit of normal for younger men and increase it for older men. Different thresholds alter the sensitivity and specificity of detection. The threshold for performance of a biopsy was ng mL which has been reduced to ng mL for men 60 by many groups based on the finding that nearly half of the men with PSAs who reached this level increased to 4 within a relatively short 4-year time frame and that once diagnosed nearly one-third had spread beyond the confines of the gland. Most PSA is complexed to a1-chymotrypsin ACT only a small percentage is free. To improve diagnostic accuracy for men with a PSA between 4 and 10 the risk of cancer is under 10 if the free PSA is 25 but as high as 56 for those with a free PSA 10 . PSA density measurements were developed to correct for the contribution of BPH to the total PSA level. PSA density is calculated by dividing the serum PSA by the prostate weight estimated from transrectal ultrasound TRUS . Values ng mL per cm3 are consistent with BPH while those suggest cancer. PSA velocity is the rate of change in PSA levels over time and is expressed most commonly as the PSA doubling time. It is particularly useful for men with seemingly normal values that are rising. For men with a PSA above 4 rates of rise ng mL per year suggest cancer while for those with lower PSA levels rates above ng mL per year should be used to advise a biopsy. As an example an increase from to in a 1-year period would warrant further testing. Free and complexed PSA measurements are used when levels are .

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