Age-related reference intervals for free and total prostate-specific antigen in a Singaporean population.
Cancer of the prostate is the sixth most frequently found cancer in Singapore. Prostate-specific antigen (PSA) is the most clinically useful tumour marker available today for the diagnosis and management of prostate cancer. To enhance the value of PSA as a screening test we developed age-specific intervals for our ethnic population. The measurement of free PSA was included in the study to calculate the free:total ratio which enhances the differential diagnosis of prostate cancer from benign prostatic hyperplasia or prostatitis. The total PSA upper limits of 10-year intervals, beginning at 30-years-old, were 1.4, 1.7, 2.3, 4.0, 6.3 and 6.6 microg/l. Free PSA cut-off limits were 0.4, 0.5, 0.5, 1.0, 1.5 and 1.6 microg/l. The free:total ratio of PSA was not age dependent. Abbott AxSym standardised their calibration material for both free and total PSA assays with the Stanford 90:10 reference material. This laboratory has implemented these age-specific reference intervals and are currently following up their pick-up rate in the detection of prostate cancer.
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Department of Laboratory Medicine, National University Hospital, Singapore. sharons@nuh.com.sg
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D000328:Adult; D017677:Age Distribution; D000368:Aged; D000369:Aged, 80 and over; D002681:China / Q000208:ethnology; D006801:Humans; D007194:India / Q000208:ethnology; D008296:Malaysia / Q000208:ethnology; D008297:Male; D008403:Mass Screening; D008875:Middle Aged; D017430:Prostate-Specific Antigen / Q000097:blood*; D011470:Prostatic Hyperplasia / Q000097:blood* / Q000453:epidemiology; D011471:Prostatic Neoplasms / Q000517:prevention & control*; D012016:Reference Values; D015203:Reproducibility of Results; D012846:Singapore / Q000453:epidemiology
D017430:Prostate-Specific Antigen