Sample stability:
-
24 hours at 20-25 o C
-
5 days at 2-8 o C
-
24 weeks at -20 o C
Units: ug/L
Reference intervals:
|
Age |
PSA |
|---|---|
|
0-50 |
<2.5 |
|
>50-60 |
<3.5 |
|
>60-70 |
<4.0 |
|
>70 |
<6.5 |
Uncertainty of Measurement: 5%
Principle: Sandwich type immunoassay with chemiluminescence detection
Reagents: Roche e-pack PRL
Analyser: Cobas e801
PSA is used for diagnosis, monitoring and detecting recurrence of prostatic cancer.
PSA should be used in conjunction with a full clinical examination, including a rectal examination.
PSA is also increased in benign prostatic hypertrophy, and levels in this condition overlap with those seen in cancer.
PSA levels >10 ug/L make prostate cancer more likely than BHP.
Prostatitis or vigorous prostatic massage may cause elevations of PSA; these usually return to normal within a few weeks.
In increase in PSA of more than 1.5 ug/L per year is suspicious and warrants referral to a urologist.
The half-life of PSA is 2 - 3 days.
In September 2015 the Ministry of Health issued a document entitled "Prostate Cancer Management and Referral Guidance". This was intended to help providers and patients make informed decisions about prostate cancer testing. The guidance document provides referral criteria including definitions of high suspicion of prostate cancer for the Faster Cancer Treatment Programme. It is available at http://tinyurl.com/PCA-MOH
Screening for prostate cancer:
Whether the benefits of screening asymptomatic men using PSA outweigh the harms, is unresolved and a matter of ongoing debate.
A positive PSA screening test usually will lead to a prostate biopsy. If cancer is found, various therapies including surgery, radiotherapy, hormonal and chemotherapy may be employed.
These therapies often impair quality of life because of side effects including impotence and incontinence.
On the other hand, prostate cancer often progresses very slowly and the majority of men who get prostate cancer do not die of the disease, but of other causes.
For every man whose life is prolonged by screening, there will be many men left with impotence and/or incontinence.
For all these reasons, many men choose not to have PSA screening.
Patients are advised to discuss all these matters with their doctor before deciding whether to have a PSA screening test.
Free PSA:
This test is not available at Labplus.
Emails to chemicalpathologist@adhb.govt.nz will receive priority attention from the on-call chemical pathologist.
If the query concerns a specific patient please include the NHI number in your email.
If email is not a suitable option, please contact the on-call chemical pathologist via Lablink (Auckland City Hospital ext. 22000 or 09-3078995).
Individual chemical pathologists may be contacted but will not be available at all times.
After-hours : contact Lablink (Auckland City Hospital ext. 22000 or 09-3078995) or hospital operator for on duty staff after hours.
Dr Samarina Musaad (Clinical Lead) : SamarinaM@adhb.govt.nz ext. 22402
Dr Cam Kyle: CampbellK@adhb.govt.nz ext 22052
Dr Weldon Chiu: WeldonC@adhb.govt.nz ext. 23427
Dr Campbell Heron: CHeron@adhb.govt.nz ext. 23427
Dr Sakunthala Jayasinghe: Sakunthala@adhb.govt.nz ext. 23427