PSA measurement is part of the prostate cancer diagnostic pathway. Prostate cancer is the most common malignancy in males in Scotland. 99% of cases are in men aged over 50 years. Risk of prostate cancer is increased if a first-degree relative has had prostate cancer or if there is a family history of BRCA associated breast or ovarian cancer. The majority of men with prostate cancer do
not have any symptoms.

Scottish Referral guidelines for suspected cancer recommend measuring PSA in men who present with unexplained possible signs and symptoms of prostate cancer such as:

• Changes to urinary patterns
• Erectile dysfunction
• Unexplained haematuria
• Lower back pain
• Bone pain
• Weight Loss

This should be done in conjunction with a digital rectal examination.

PSA may be requested by secondary care to:

• Determine prognosis in patients with prostate cancer
• Monitor patients with diagnosed prostate cancer

PSA may also be requested by asymptomatic patients.

PSA should not be measured in any of the following situations:

• In a patient with a known UTI or who has been catheterised or has had another invasive procedure such as a prostate biopsy (PSA may stay elevated for six weeks)
• In a patient known to have recently ejaculated (PSA may be raised within three days of ejaculation)
• In a female patient (transgender patients should be assessed as per local protocols).

PSA should be repeated if:

• It is mildly elevated, and the initial sample was collected when the patient had a recently ejaculated or had a UTI, been catheterised or had any other invasive procedure 
• Directed by secondary care
• Presentation of new symptoms, which are suggestive of prostate cancer.

1. Scottish Referral Guidelines for Suspected Cancer [Internet]. NHSScotland; 2019. Urological Cancers; [updated 2022 Sep; cited 2022 Oct 04]. Available from: https://www.cancerreferral.scot.nhs.uk/urological-cancers/?alttemplate=guideline