Adult patient:
Clotted blood tube
(Serum gel separator clot activator tube)
Minimum blood volume: 5 mL
Paediatric patient:
Paediatric clotted blood tube
Number of vials: 2
Minimum blood volume: 1.6 mL
Authorisation code required
No
24 Hr available service
No
Method
Immunoassay
Reference interval
< 4 µg/L
Serum PSA is standardised against Stanford Reference Standard/WHO 96/670. Local population data on risk assessment of prostate cancer with PSA testing and digital rectal examination guided biopsy can be referred to HK Pract 2009; 31: 128 - 32.
(Source: from manufacturer's kit insert)
Clinical indication
Diagnosis and monitoring of prostatic carcinoma
The test is not recommended as a stand-alone screening test for carcinoma of the prostate.
Result interpretation
The result should always be interpreted in conjunction with the findings on digital rectal examination and other clinical findings.
Marked elevation is indicative of carcinoma, but normal or slightly elevated PSA levels do not exclude it.
The most common non-malignant cause of increased PSA is benign prostatic hypertrophy. However, levels are also increased in prostatitis, prostatic ischaemia and / or infarction and acute renal failure.
Assays for total PSA measure both free and complexed forms. The complexed form is probably more specific for prostatic cancer but the diagnostic role of complexed PSA assays is not yet established.
Results that do not correspond to the clinical findings should be repeated on a fresh sample.
PSA is most useful in monitoring the course of prostatic carcinoma. Persistent elevation of PSA following treatment is indicative of recurrent or residual disease.
Measurement of uncertainty
Frequency of measurement
Daily