Effect of marathon running on total and free serum prostate-specific antigen concentrations

Context.-Prostate-specific antigen (PSA) is an important tumor marker for the most frequently diagnosed cancer in the United States. A major limitation of this marker is falsely elevated results in patients who are found not to have prostate cancer. The effects of vigorous physical exertion on PSA concentrations are controversial. Objective.-To determine the effects of marathon running on PSA levels. Design.-Measurement of total and free PSA levels in the sera of participants in a marathon before and within 4 and 24 hours after the race. Results.-None of the participants had elevated total PSA levels before the race. Although we found no statistically significant changes in average total or free PSA concentrations at either time point, after the marathon, 2 (111%) of 18 runners had total PSA concentrations outside the standard reference range. Changes in total PSA levels did not correlate with age or prerace PSA concentrations. Free PSA levels were not statistically significantly changed after the race and did not allow a reliable determination of exercise-induced PSA elevations. Conclusions.-Although it may not be necessary for men to abstain from exercise involving running before blood draws for PSA analysis, elevated PSA concentrations may be observed in some individuals after participation in a major sporting event. In these cases, repeat measurements should be considered at a time significantly removed from such exercise.