PSA velocity may effectively measure aggressive prostate cancer

PSA velocity is an accurate gauge of prostate tumor aggression and danger, even when PSA levels are so low as to not warrant a biopsy, according to researchers at the Brady Urological Institute, Johns Hopkins University School of Medicine, Baltimore. This finding may add a new level of predictive accuracy to prostate cancer testing, the value of which has remained controversial under currently accepted guidelines, the researchers say.

“Our data provide a further argument for PSA testing that begins relatively early in life, when PSA levels are usually lower and prostate enlargement is not a confounding factor in diagnosis,” said H. Ballentine Carter, MD, lead author and director of the division of adult urology at Brady. “We would recommend that men at around age 40, not 50, have their PSA checked to develop a baseline against which to compare future changes, since even a slight rise in PSA may indicate a potential for cancer down the road.”

Using serum samples dating as far back as 1958, Dr. Carter and colleagues determined PSA velocity in 980 men up until May 2005. They found that the PSA velocity determined at a time when PSA levels would not have triggered a biopsy (<4.0 ng/mL) were predictive of death from prostate cancer 20 to 30 years later.

Those men whose PSA velocity was lower had a 92% chance of not dying of prostate cancer 25 years later, whereas those with a higher PSA velocity had a 54% chance of not dying of prostate cancer. The rates of death were 1,240 in 100,000 for subjects with a higher velocity compared with 140 in 100,000 for those with lower velocities.

The study was published recently in the Journal of the National Cancer Institute (2006; 98:1521-7).

Dr. Carter emphasized that an important difference between the current research and previous studies is that the individuals in the current research were not selected; rather, they were taken at random from a large, ongoing study, thus more accurately representing the U.S. population.