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Haematuria
Testicular lump/pain
Ureteric Colic
Bladder Obstruction
Raised PSA

 

Raised PSA Blood Test

Prostate specific antigen (PSA) is a marker of prostate cancer

Prostate specific antigen is a glycoprotein issued only by prostatic cells. Its function is to liquefy the semen after ejaculation to allow the sperms to swim more freely. PSA is not found in females. It is used as a marker for prostate cancer but it has its pitfalls. It can also be raised in other non malignant prostatic disorders. It is also used to monitor the progress of prostate cancer.

Age

The normal value for the PSA is age dependent

Age

Normal Limit

Under 50

< 2.5

50 – 60

<3.5

60 – 70

<4.5

70 – 80

<6.5

PSA Density

This refers to the relationship of the PSA to the size of the prostate. It is not used nowadays.

PSA Velocity

This refers to the rate of change of the PSA over time. It has prognostic implications in prostate cancer.

Free PSA

Most of the PSA in the blood is bound to proteins. A small proportion is free in the serum. A decreased ratio of free PSA to total PSA may indicate that a cancer is more likely.

Screening

PSA is ordered as part of the investigations of patients with bladder outflow obstructive symptoms.

Screening for prostate cancer is controversial.  Some experts advocate screening in all males over 50 years and over 45 in high risk patients with a family history of prostate cancer.

Care should be exercised in screening asymptomatic men. If the PSA is raised then further investigations will be necessary. These tests are not without their risks.

The risk of having cancer if the PSA is between 4 and 10 is about 25%. Therefore the majority of men with a slightly raised PSA do not have cancer. These results are known as false positives.

Also some men with prostate cancer have a normal PSA. These results are known as false negatives.

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History

If the PSA is raised then a full urological history is taken

  • Bladder outflow obstructive symptoms
    • Hesitancy
    • Poor flow
    • Post voiding dribbling
  • Irritative symptoms
    • Frequency
    • Nocturia (rising at night)
    • Urgency

Examination

Abdominal examination may reveal an enlarged palpable bladder which may or may not be tender.

A digital rectal examination (DRE) is required. The prostate has two lobes separated by a central groove or sulcus. The consistency is soft. In prostate cancer the gland feels firm to hard. Nodules may be palpable in one or both lobes. The central sulcus may be obliterated and the surrounding tissues may be firmer or harder in more advanced cases.

Investigations

Blood Tests

  • A full blood count and urea and creatinine assess renal function.

Ultrasound

  • A renal ultrasound will detect any hydronephrosis (obstruction to the kidneys).

TRUS

  • This is a TransRectal Ultrasound Scan. A probe in inserted into the rectum to scan the prostate. Biopsies of the prostate are taken during a TRUS.  This technique can have complications. Haematuria and infections are the main ones.

The further management of the patient is governed by the results of the biopsies. If a carcinoma is diagnosed then the options detailed in prostate_cancer in the urology disorder section are appropriate. If the biopsies are benign then further PSA monitoring is required.  A rising PSA or abnormal DRE would indicate further biopsies are necessary.

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