About this page. This is a plain English summary of how prostate cancer is first looked for. It does not replace medical advice from your own doctor or specialist.
For full information and references, please read the detailed page.
The two starting tests
Prostate cancer is usually first picked up in one of two ways:
- A PSA blood test that comes back higher than expected.
- A digital rectal examination (DRE) of the prostate that feels different to normal.
Doing both is important. Around 1 in 10 prostate cancers do not raise the PSA, so the rectal examination still matters.
What is PSA?
PSA stands for prostate specific antigen. It is a protein made by the prostate. A small amount of it leaks into the blood, where it can be measured with a simple blood test.
If the PSA level is higher than expected, the chance of prostate cancer goes up. A raised PSA does not mean you definitely have cancer; it means the prostate is worth a closer look.
Different ways to read the PSA result
- The level itself. Doctors used to use a single cut-off of 4. Now we usually use age-adjusted levels, because PSA naturally rises a little with age. In younger men, a level above 2.5 may already be a concern.
- How fast it is rising (PSA velocity). Even if the PSA is low, a level that is climbing quickly raises the level of concern.
- The free-to-total ratio. Some PSA floats freely in the blood and some is bound to other proteins. A low ratio of free PSA points more towards cancer; a high ratio points more towards a benign cause.
The digital rectal examination (DRE)
The DRE is a quick examination where the doctor feels the prostate through the wall of the back passage with a gloved finger. Many men worry about it, but it is usually painless and over in less than a minute.
A normal prostate is about the size of a walnut, smooth, and feels a bit like the tip of your nose. If it feels firmer than that, or if there is a lump or an irregular area, that can be a sign that further tests are needed.
Important things to know
- A raised PSA does not always mean cancer. It can also be raised by an enlarged prostate, a urine infection, or recent activity such as cycling or sex.
- A normal PSA does not always mean no cancer. About 1 in 10 prostate cancers do not raise the PSA at all, which is why the DRE is still done.
- The decision about whether to have a PSA test, and how often, is best made together with your GP or specialist. It depends on your age, family history, and personal preference.
- One result on its own rarely tells the whole story. The trend over time is often more important than a single number.
What you can do next
- Read the full detailed page with references and the BAUS PSA brochure.
- Short version overview of prostate cancer for the bigger picture.
- Short version: the MRI scan, which is often the next step after a raised PSA.
- Request a second opinion on a PSA result.
- Call 02 8382 6980 to make an appointment.