Demographics, Lifestyle May Affect Prostate Cancer Test
Interpretation of PSA velocity may be biased by age, race and other factors
MONDAY, Dec. 12 (HealthDay News) -- Age, race, weight change, energy intake and the use of calcium supplements are all associated with significant differences in the rate of change in prostate specific antigen (PSA) over time, or PSA velocity, and may bias the clinical interpretation of this prostate cancer test, according to a study in the Jan. 15 issue of Cancer.
Alan R. Kristal, Dr.P.H., of the Fred Hutchinson Cancer Research Center in Seattle, and colleagues analyzed data on 3,341 prostate cancer-free participants in the placebo arm of the Prostate Cancer Prevention Trial. Using linear regression they assessed the impact of age, race, smoking, body mass index, physical activity, diet and use of supplements on PSA concentration and PSA velocity over a six-year period.
While there were small differences in PSA concentration associated with lifestyle and demographic factors, these were not significant enough to bias the interpretation of traditional PSA tests. However, in black men, PSA velocity was 1.2 percentage points higher than in white men. In men 70 and older, PSA velocity was 1.2 percentage points lower than in men aged 50-59. Lower PSA velocity was also associated with low energy intake, weight gain and the use of high-calcium supplements.
"Clinical interpretation of PSA velocity may be biased by these factors," the authors conclude.