Patient demographics, lifestyle affect PSA velocity

PSA velocity can be significantly affected by age, race, and diet, leading to falsely lower or elevated values and possible misinterpretation, according to researchers from the Fred Hutchinson Cancer Research Center, Seattle.

Alan Kristal, MD, and colleagues, reviewed PSA and PSA velocity data from 3,341 cancer-free men and found that PSA velocity decreased as men aged and increased in those with higher-calorie diets. PSA velocity in African-Americans was on average almost twice the level of Caucasians and was lower among users of high-dose calcium supplements.

The team also found that single determinations of PSA concentration are higher as men age and lower in obese men. These differences, while statistically significant, were considered minimal and would have little influence on clinical interpretation of PSA value.

“Race, smoking, age, energy intake, calcium supplement use and weight change were associated with substantial differences in PSA velocity," the authors concluded, "and clinical interpretation of PSA velocity could be biased by these factors."

The study was published in the Dec. 12, 2005 online edition of Cancer.