Prostate specific antigen blood test
Prostate specific antigen (PSA) is a protein made by both normal prostate cells and cancerous prostate cells. PSA levels are measured using a blood test, and the results are given as nanograms of PSA per millilitre (ng/mL) of blood. The PSA test does not specifically test for cancer.
If the PSA result is higher than the typical range for your age (e.g. above 3 ng/mL for people aged 50–59) or is rising quickly, this may indicate the possibility of prostate cancer. However, the amount of PSA in the blood can be raised even when you do not have cancer.
Other factors that can increase PSA levels include benign prostate hyperplasia, recent sexual activity, an infection in the prostate, or a recent digital rectal examination. Some people with prostate cancer have normal PSA levels.
Because your PSA levels can vary from day to day, your doctor will usually repeat the test to help work out your risk of prostate cancer.
There are some other blood tests your doctor may suggest:
Free PSA or free-to-total test
This measures the PSA molecules in your blood that are not attached to other blood proteins (free PSA). This test may be suggested if your PSA score is above 3 ng/mL and your doctor is not sure whether you need a biopsy. The free PSA test measures the ratio of free PSA to total PSA. A low level of free PSA compared to total PSA may be a sign of prostate cancer.
Prostate health index (PHI)
This measures three different forms of the PSA protein. PHI is not widely used in Australia and is not covered by Medicare.
Download a PDF booklet on this topic.
Dr Amy Hayden, Radiation Oncologist, Westmead and Blacktown Hospitals, and Chair, Faculty of Radiation Genito-Urinary Group (FROGG), The Royal Australian and New Zealand College of Radiologists, NSW; Prof Shomik Sengupta, Professor of Surgery and Deputy Head, Eastern Health Clinical School, Monash University, and Visiting Urologist and Uro-Oncology Lead, Urology Department, Eastern Health, VIC; A/Prof Arun Azad, Medical Oncologist, Urological and Prostate Cancers, Peter MacCallum Cancer Centre, VIC; Ken Bezant, Consumer; Dr Marcus Dreosti, Radiation Oncologist, GenesisCare, and Clinical Strategy Lead, Oncology Australia, SA; A/Prof Nat Lenzo, Nuclear Physician, Specialist in Internal Medicine, Group Clinical Director, GenesisCare Theranostics and The University of Western Australia, WA; Jessica Medd, Senior Clinical Psychologist, Department of Urology, Concord Repatriation General Hospital, and HeadwayHealth Clinical and Consulting Psychology Services, NSW; Caitriona Nienaber, 13 11 20 Consultant, Cancer Council Western Australia; Graham Rees, Consumer; Kerry Santoro, Prostate Cancer Specialist Nurse, Southern Adelaide Local Health Network, SA; A/Prof David Smith, Senior Research Fellow, Cancer Research Division, Cancer Council NSW; Matthew Starr, Consumer. We also thank the health professionals, consumers and editorial teams who have worked on previous editions of this title. This booklet is funded through the generosity of the people of Australia.
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