PSA Complexity

A recent NEJM article 350:22 2239 2004 by Thompson et. al. had a trial

which included 2950 men whose PSA in the yearly tests never exceed 4.0 (the upper normal value) and never had any abnormality on rectal examination. After seven years these patients underwent prostate biopsy and prostate cancer was diagnosed in 15.2%. Of these 14.9% had pathology consistent with more severe disease. The patients ages ranged from 62-91.

What are we to make of this study? It has been well known that from autopsy

studies in this age population many people had prostate cancer and did not know it. The

average of such trials is around 30%. Thus this study should not come as a total

surprise and yet it really hits home that we need better markers for prostate cancer

and a better understanding of which patients will most likely just coexist with the

cancer versus those who will die from it. The problem with values above 4.0 which

are false positives is well known and we also here need better ways of differentiating

what is happening. So for the men the next time they get back a normal PSA test and

a normal rectal exam they must realize that in 14% of them the cancer still lurks.

However, In general I would not recommend biopsy for these patients but if there PSA

is rising rapidly and or they have a strong family history and are near the 4.0 level

then it would be worthwhile.

Alexander Mazziotti, MD, Ph.D.