Prostate Cancer Screening - Is It Overdone?

It’s take years to get men sufficiently educated to overcome their anxieties and undergo prostate cancer screening.  Now it looks as if the effort has been wasted – screening may be overdone.  In other words, screening is associated with considerable over-diagnosis, so that while many men will be found to have prostate cancer, it won’t shorten or impair their survival.  One of several studies that demonstrate this has just been posted online in the British Medical Journal.  It was designed to determine the value of a single prostate-specific antigen (PSA) blood test at age 60 in pinpointing men who are likely to die from prostate cancer.

This was a Swedish study that had a 25-year follow-up.  There were 1,167 men aged 60 at enrollment in 1981, when they provided blood samples for PSA determination.  During the follow-up period, they were monitored for death or metastases from prostate cancer.       

After analyzing the PSA levels for the 35 deaths and the 43 cases of metastases, it emerged that 90% of deaths occurred in the 25% of men who had, at age 60, PSA levels above 2 ng/mL.  Whereas men with PSA levels at 1 ng/mL or below had extremely low rates of prostate cancer at age 85 – 0.2% death and 0.5% metastases. 

The chief researcher recommends, based on these results, that, instead of routine PSA screening for all men, men are screened at 60 years of age, and repeat screening is confined to those with levels at 2 ng/mL or above.  Those with levels at 1 ng/mL or below need no further PSA screening.  Between 1 and 2 ng/mL – screen every 3-5 years.  This procedure would reduce over-diagnosis in men at low risk of prostate cancer death and should improve compliance with screening in those who have the most to gain.

Not surprisingly, there are voices who feel this approach is too simple:  “a single test represents merely a snapshot in time”, and “there’s no PSA level below which you can state that there’s definitely no cancer”.  Nevertheless, it’s a big step forward, in my view, as it incorporates known risk levels into the decision to screen men after 60 years of age.