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Test Code 144 Prostate Specific Antigen (PSA), Total and Free

Important Note

Manipulation of the prostate by rectal examination within 48 hours of specimen collection may result in elevated results. 5 alpha-reductase inhibitor drups may affect PSA levels.

Human anti-mouse antibodies (hama) may be present in samples from patients who have received immunotherapy or diagnostic procedures utilizing monoclonal antibodies or in individuals who have been regularly exposed to animals. Additionally, other heterophile antibodies, such as human anti-goat antibodies may be present in patient samples. Manufacturers formulate assays to minimize the effects of these antibodies; however careful evaluation of patient results must be done when patients are known to have such antibodies.

Additional Codes

ALAB: PSATF

PowerChart: PSA Total and Free

MA Cerner: PSA, Total and Free

Test Method

Total: Equimolar Two-Site Immunoenzymatic "Sandwich" Assay; Beckman DxC700AU

Free: Two-Site Immunoenzymatic "Sandwich" Assay

Specimen Requirement

0.5 mL serum required.

Additional Specimen Collection Information

Collect blood in a red-top tube. SST (serum gel tubes) are acceptable. Serum should be separated from contact with the cells within 2 hours of collection. Specimens not analyzed within 3 hours of collection must be refrigerated. If a specimen is to be stored longer than 24 hours it must be stored frozen at -20°C.

Performance

Testing is performed Monday through Sunday.

Routine: Typically completed within 4 hours after the specimen arrives at the testing site.

Expedite: Typically completed within 1 hour after the specimen arrives at the testing site.

STAT: Typically completed within 30 minutes after the specimen arrives at the testing site.

Reference Values

PSA Total

Female: < 0.2 ng/mL

Male:

Age, Years

Total PSA ng/mL

Age, Years

 

Total PSA ng/mL

Age, Years

 

Total PSA ng/mL

≤ 40

0-2.0

54

0-3.2

68

0-4.9

41

0-2.1

55

0-3.3

69

0-5.1

42

0-2.2

56

0-3.4

70

0-5.3

43

0-2.3

57

0-3.5

71

0-5.4

44

0-2.3

58

0-3.6

72

0-5.6

45

0-2.4

59

0-3.7

73

0-5.8

46

0-2.5

60

0-3.8

74

0-6.0

47

0-2.6

61

0-4.0

75

0-6.2

48

0-2.6

62

0-4.1

76

0-6.4

49

0-2.7

63

0-4.2

77

0-6.6

50

0-2.8

64

0-4.4

78

0-6.8

51

0-2.9

65

0-4.5

79

0-7.0

52

0-3.0

66

0-4.6

≥ 80

0-7.2

53

0-3.1

67

0-4.8

 

 

Free PSA: Not established


% Free PSA:
 

  Cancer Probability for Men with Total PSA 4-10 ng/mL:

% Free PSA

Age 50 to 64 Years

 Age 65 to 75 Years

0-10 %

56 %

 55 %

10-15 %

24 %

 35 %

15-20 %

17 %

 23 %

20-25 %

10 %

 20 %

>25 %

5 %

 9 %

 

CPT Code Information

84153 Chemistry: Prostate specific antigen; total

84154 Chemistry: Prostate specific antigen; free

Useful For

The percentage of measured prostate-specific antigen (PSA) existing in the free form (Free:total PSA ratio) is useful in assessing the risk of prostate cancer in patients with borderline or moderately increased total PSA (4.0-10.0 ng/mL) and has been used to help select men who should have follow-up prostate biopsy.

Most prostate cancers are slow growing, so the utility of prostate cancer screening is marginal in most men with a life expectancy of <10 years.

LOINC Code Information

53764-7 Prostate Specific Ag Panel-Serum Or Plasma

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