Pathology Handbook

Prostate Specific Antigen

Synonyms

PSA

Clinical Indications

In combination with digital rectal examination PSA can aid diagnosis of prostate cancer in symptomatic patients. PSA is also useful for monitoring patients with diagnosed prostatic cancer. The value of PSA in screening asymptomatic men has not been proven in clinical trials.

Request Form

Request on ICE

Availability

On request

Specific Criteria

Should not be used for screening in asymptomatic men.

NOTE:  If a patient is having serial tumour marker levels monitored the tests must all be done at the same laboratory as there are significant variations between assays

Patient Preparation

Urological manipulations affect PSA levels and if possible sample should be taken before procedure. Effects are as follows:

DRE / 
Prostate massage

May cause minor increases in some patients, take sample for PSA before procedure.

Ejaculation

Results conflicting but may increase PSA levels.

TURP / 
Needle Biopsy

Increases PSA levels significantly. Wait at least 6 weeks before taking sample for PSA levels 

Ultrasound

Increases PSA levels in a minority of patients

Cystoscopy

Flexible cystoscopy does not appear to increase PSA levels but rigid cystoscopy may increase levels.

Turnaround Time

Same Day

Specimen

Vacutainer gold top

Volume

2 ml

Container

Yellow top (SST) tube

Reference Range

Age Range

PSA µg/L

< 40 years

<2.5

40 - 49

<2.5

50 - 59

<3.5

60 - 69

<4.5

70 - 79

<6.5

> 79 years

<7.5

An increase in PSA (velocity) of up to 1 µg/L/year is normal

Half-life in Serum

Approx. 2.5 days after radical prostatectomy. Half-life after radiotherapy may be many months.

Interpretation

Benign prostatic hypertrophy (BPH), acute and chronic prostatitis, urinary retention, prostate biopsy, prostate massage and ejaculation may give rise to transient elevation of PSA levels.  Patients should be advised to avoid sexual intercourse for 24 hours before being tested.