PSA levels by age
In their most recent analysis of the PSA study involving 36,000 men, Dr. Catalona’s team, in collaboration with Stacy Loeb, MD, now a urology resident at Johns Hopkins, has revealed that the median PSA value is 0.7 for men in their 40s, 0.9 for men in their 50s, 1.3 for men in their 60s, and 1.7 for men in their 70s. If a man had a PSA value below the median for his age group, his risk of being diagnosed with prostate cancer during the study was very low, Dr. Catalona noted. If his PSA was higher than the median value for his age group, the risk was higher than in the general population.
“The higher the PSA, the greater the risk for prostate cancer and the greater the risk for aggressive disease,” Dr. Catalona says. “It is noteworthy that all of these median values are below 2.5 and substantially below 4.0.”
Dr. Catalona says his current approach is to be concerned about any man whose PSA is above the median value for his age group. This concept has been incorporated into the National Comprehensive Cancer Center Network (NCCN) guidelines for prostate cancer screening.
“My concern about a patient’s having prostate cancer becomes heightened if a PSA higher than the age-group median does not come down with antibiotic therapy or spontaneously on repeated measurements,” Dr. Catalona relates.
“I strongly recommend a biopsy for any man whose PSA shows a steadily upward trend, especially if it increases more than 0.35 per year consistently. The importance of a steadily rising PSA has been quantified by Dr. Carter of Johns Hopkins and is called a ‘risk count number’—that is, the number of times the PSA has increased over time. And I believe a biopsy should definitely be considered in any man whose PSA is higher than 2.5, unless he has an enlarged prostate and a reasonably high percentage of free PSA, both suggesting
benign hyperplasia as the cause of the elevated PSA.”
PSA testing is just one of the diagnostic quandaries stemming from uncertainty about normal values. Another is the use of glomerular filtration rate in diagnosing renal disease. This issue will be discussed in detail in the next issue.