Diagnosis of Prostate Cancer in the Community

Email Raji.Kooner@svha.org.au or call 02 8382 6980 for a confidential appointment.

Prostate cancer is usually diagnosed two ways, either with a PSA elevation which is a blood test that’s elevated or on digital rectal examination, examination of prostate.1

PSA is a protein that’s produced by the prostate and it seeps into the blood stream. 

The higher the PSA, the higher the risk of prostate cancer.2

It’s a simple blood test that’s taken and if the level is elevated your chance of prostate cancer is higher. 

So we have various ways of using the PSA, we use the absolute PSA level and traditionally we used to use a level of 4 as the cut off.1

More recently we’ve used age related levels because your PSA goes up as you get older.1

Recently there’s been data to show that we should use a new cut off of 2.5 as the upper range of normal.3

So particularly in young men if their PSA is above 2.5 the risk of cancer is significantly elevated.4,5

Another very important way of using PSA is the velocity, the rate of rise of PSA and if the PSA, even if it’s low is rising reasonably quickly the risk of cancer is elevated and that might trigger us to, to, for further action in terms of a biopsy.6

The last thing that we use PSA for is, is, is the free to total ratio. 

So PSA is protein, it floats around the bloodstream, some of it’s free floating around, some is bound to a protein. 

If we measure the amount that’s free floating around versus the total amount we get a ratio test and for every given PSA if you have a low ratio your chance of prostate cancer is higher than if you have a high ratio.7

So these factors, the absolute level, the age related levels, new cut off of 2.5, the velocity and free determined ratios are the important things that we use when determining the, the actual PSA value in a patient and the impact that will have on that patient.

We also diagnose prostate cancer on digital rectum examination and that’s a very simple test. 
It’s, some people are quite concerned about it but it’s very painless.8

We examine the prostate and we feel the prostate and generally the prostate is usually the size of a walnut and it’s smooth, there’s no nodules, there’s no lumps or bumps, it feels like the tip of your nose. 

If it feels firmer than that then that can be the sign of possible prostate cancer.9

So the two ways is the blood test, the PSA and the digital rectal examination. 

It’s important to do both because 10% of cancers don’t actually produce PSA10 so it’s important to do both tests.


1. Diagnosing prostate cancer - Cancer Council Victoria - https://www.cancervic.org.au/cancer-information/types-of-cancer/prostate_cancer/diagnosing_prostate_cancer.html
2. Prostate-Specific Antigen (PSA) Test - National Cancer Institute - https://www.cancer.gov/types/prostate/psa-fact-sheet
3. Prostate Cancer: Age-Specific Screening Guidelines - John Hopkins Medicine - https://www.hopkinsmedicine.org/health/conditions-and-diseases/prostate-cancer/prostate-cancer-age-specific-screening-guidelines
4. National Library of Medicine - https://pubmed.ncbi.nlm.nih.gov/17681060/
5. Prevalence of prostate cancer among men with a prostate-specific antigen level < or =4.0 ng per milliliter https://pubmed.ncbi.nlm.nih.gov/15163773/
6. National Cancer Institute - https://www.cancer.gov/types/prostate/psa-fact-sheet#what-is-a-normal-psa-test-result
7. Free to Total PSA Testing - Prostate Cancer Foundation of Australia - https://www.prostate.org.au/testing-and-diagnosis/psa-testing/free-to-total-psa-testing/
8. Patients' perceptions of pain and discomfort during digital rectal examination - FR Romero (2008) - https://www.redalyc.org/pdf/1810/181013947018.pdf
9. Benign Prostatic Hyperplasia (BPH) - Johns Hopkins Medicine - https://www.hopkinsmedicine.org/health/conditions-and-diseases/benign-prostatic-hyperplasia-bph
10. Association of very low prostate-specific antigen levels with increased cancer-specific death in men with high-grade prostate cancer - Brandon A. Mahal MD, Ayal A. Aizer MD, et al - https://acsjournals.onlinelibrary.wiley.com/doi/10.1002/cncr.29691