The PSA Test: A Decision, Not a Routine Check

Prostate cancer is the most common cancer in men in the UK. There is a simple blood test for it. And yet there is no national screening programme, which strikes most people as an oversight.

It is not. It is a deliberate decision, and understanding why is the only way to make a sensible choice about whether to have the test.

What PSA actually measures

Prostate specific antigen is a protein made by the prostate. The name is the problem: it is specific to the prostate, but not to cancer. Anything that irritates or enlarges the prostate pushes it up.

That gives the test two failings that pull in opposite directions:

• Most men with a raised PSA do not have prostate cancer. Far more often it is benign enlargement, infection or inflammation
• Some men with prostate cancer have a normal PSA. A reassuring result is not a guarantee

Things that raise PSA and have nothing to do with cancer

These matter, because a falsely raised result leads to weeks of anxiety and sometimes to an unnecessary biopsy:

• Benign prostate enlargement — extremely common with age, and the single biggest cause of a raised reading
• Urine infection or prostatitis — can raise PSA dramatically and for weeks. Wait at least six weeks after either before testing
• Ejaculation in the previous 48 hours
• Vigorous cycling in the previous 48 hours — genuinely, and a common cause of a puzzling result
• A rectal examination, catheter, or any prostate procedure beforehand
• Simply getting older — the prostate grows, and PSA rises with it

How to prepare properly

If you are having the test, give it a fair chance: no ejaculation and no cycling for 48 hours, no test within six weeks of a urine infection or prostatitis, and have the blood taken before any rectal examination rather than after.

The harder problem: overdiagnosis

This is the part that explains the absence of a screening programme, and it is counter-intuitive.

Many prostate cancers grow so slowly that they would never have caused symptoms or shortened life. A man can die at 85 with prostate cancer he never knew about, of something else entirely.

Screening finds those cancers. And once found, a cancer is difficult to leave alone — for the man and for his doctors. The treatments that follow carry real and lasting costs: urinary incontinence and erectile dysfunction are common after surgery or radiotherapy.

So screening everyone would mean a significant number of men treated — and left with those consequences — for a disease that was never going to harm them. That is the trade the UK has judged not to be worth making as a blanket policy.

What has genuinely improved

The picture is better than it was, and this changes the calculation.

MRI is now done before biopsy rather than after. A multiparametric MRI can identify which men actually need a biopsy and where to target it. That means fewer men having an unnecessary biopsy, fewer insignificant cancers found, and better detection of the ones that matter.

Active surveillance is now standard for low-risk disease — monitoring rather than treating, with treatment reserved for signs of progression. That substantially reduces the overtreatment problem, though not the anxiety of knowing.

Who should think seriously about testing

Risk is not spread evenly, and this is where the decision tips:

• Men of Black African or African-Caribbean family background — roughly double the risk, and it tends to present younger. Worth considering from around 45 rather than 50
• A father or brother with prostate cancer — particularly diagnosed young. Also worth starting around 45
• A known BRCA2 variant, or a strong family history of breast and ovarian cancer
• Otherwise, most men are advised to consider it from 50

In England, any man over 50 can request a PSA test from his NHS GP under the informed choice arrangements, after a discussion of the pros and cons. That is a right, not a favour, and it is not widely known.

Symptoms are a poor guide — in both directions

This confuses almost everyone.

Early prostate cancer usually causes no symptoms at all. It grows in a part of the gland away from the urethra, so it does not affect urination until late. Waiting for symptoms is not a strategy.

And the urinary symptoms men do get — getting up at night, a weak stream, hesitancy, dribbling — are usually benign enlargement, not cancer. They are worth sorting out because they are miserable, but they are not in themselves an alarm.

What does need urgent assessment is blood in the urine or semen, new bone pain particularly in the back, hips or ribs, unexplained weight loss, or a rapidly rising PSA on repeat testing.

Making the decision

There is no correct answer here, which is precisely why it is framed as a choice.

Reasonable to test if you would rather know, would accept the possibility of investigation for something that turns out benign, and would be able to live with active surveillance rather than demanding immediate treatment.

Reasonable not to test if the prospect of a raised result and a chain of investigations would cause you more harm than the information is worth, or if you would find it impossible to leave a low-risk cancer untreated.

What is not reasonable is having the test without knowing any of the above, then discovering the implications when the result arrives. The conversation belongs before the blood test, not after it.

We can arrange a PSA test and, more importantly, have that conversation properly first — and arrange onward referral where a result warrants it.