PSA test is not a yes-no test: How Switzerland avoids overdiagnosis

With few preventive topics are hope and worry as closely intertwined as with prostate cancer. A PSA test can give an indication before an aggressive tumour causes symptoms. But it can also set off further tests, biopsies and treatments even though a detected tumour would never have become dangerous during a man's lifetime. Both outcomes are possible. That is why the question «test yes or no?» points in the wrong direction: what matters is whether an individual man can benefit from the work-up after weighing it up in an informed way.

There is no evidence that Switzerland faces a nationwide «overdiagnosis crisis». No robust nationwide rate is available. Good care or high survival rates therefore allow no conclusion about overdiagnosis – nor about its opposite. What is established is this: the risk of overdiagnosis and overtreatment is scientifically recognised. It is a key reason why professional societies do not recommend undifferentiated mass PSA screening.

An elevated value is a signal, not a diagnosis

PSA stands for prostate-specific antigen. The blood value is organ-related but not cancer-specific. A benign enlargement of the prostate or an inflammation can also raise it. An abnormal result therefore does not answer whether a clinically significant cancer is present. It only opens up that question.

The Krebsliga (Swiss Cancer League) points out that PSA early detection can make aggressive tumours visible at an earlier stage. At the same time, slow-growing tumours may be found that would never have caused symptoms without the test. The consequences are not merely psychological: a biopsy is an invasive procedure, and cancer treatment can impair continence and sexual function, among other things. These possible harms belong in counselling just as much as the chance of detecting a dangerous tumour in time.

The European professional guideline therefore recommends a risk-adapted strategy. Family history, known genetic changes, ethnic origin, earlier findings and general state of health can play a role. In asymptomatic men with a life expectancy of less than 15 years, the benefit of early diagnosis is likely to be small according to the EAU guideline; age alone is not sufficient for this assessment. The point is not to turn people away, but to avoid unnecessary burdens with no realistic prospect of benefit.

No national programme – but a good decision is possible

Switzerland has no national programme for systematic early detection of prostate cancer. That does not mean PSA tests are prohibited or useless. It means that the quality of the individual decision matters especially. Anyone considering a test should know what an abnormal value can set in motion: will it be repeated? When does an MRI come into consideration? When is there more to be said for monitoring than for a biopsy?

For men without symptoms and a PSA value between 3 and 10 nanograms per millilitre, the EAU guideline first recommends a repeat test under standardised conditions before further investigations take place. Depending on the situation, MRI, risk calculators or additional markers can then help to refine the decision for or against a biopsy. This is not a rigid recipe. Reading an MRI and choosing the next step require experience and counselling that takes the individual case seriously.