Increasing Antigen Levels Predicts Aggressive Prostate Cancer

Longitudinal measures of prostate specific antigen (PSA) improve the accuracy of aggressive prostate cancer detection when compared with a single measurement of PSA alone.

As a rule, the higher the PSA level in the blood, the more likely a prostate problem is present, but many factors, such as age, race, and noncancerous conditions can affect PSA levels.

Scientists from Kaiser Permanente (Pasadena, CA, USA) collaborating with others, retrospectively examined the electronic health records of 219, 388 men ages 45 and older who had at least one PSA measurement, while some had at least three PSA measurements. This cohort was followed from January 1, 1998, to December 31, 2007, for the development of biopsy-confirmed prostate cancer.

The annual percent changes in total serum PSA levels were estimated using linear mixed models. The accuracy of prostate cancer prediction was assessed for prostate cancer overall and for aggressive disease with a Gleason score equal to or greater than seven, and was compared with that of a single measure of PSA level using area under the receiver-operating characteristic curves.

The study found that annual percent changes in PSA more accurately predicted the presence of aggressive prostate cancer when compared to single measurements of PSA alone, but only marginally improved the prediction of prostate cancer overall. The men in the cohort showed a mean change of 2.9% in PSA levels per year and the rate of change in PSA increased modestly with age.

Lauren P. Wallner, PhD, MPH, the study lead author, said, “The results of this study could provide clinicians with a better prostate cancer preventive strategy that could help differentiate between men with an aggressive form of the disease and those who have slow growing, indolent cancer that may not necessarily merit treatment. Our study demonstrates that repeated measurements of PSA over time could provide a more accurate, and much needed detection strategy for aggressive forms of prostate cancer.” The study was published on January 15, 2013, in the British Journal of Urology International.

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