"There’s a difference in prostate physiology between black and white men — absolutely no question about that," says lead author Jackson E. Fowler Jr, MD, professor of surgery and chief of the division of urology at the University of Mississippi School of Medicine in Jackson. "The prevalence of cancer and HGPIN [in African-American men] is higher and their PSA tends to be higher."

Fowler and his colleagues performed biopsies on 1,050 men (411 African Americans and 639 whites) who were suspected of having prostate cancer after digital rectal examination, elevated PSA levels or both, and found HGPIN more than twice as often in African-American men as in whites.

PSA, a protein produced in the prostate gland, is present in healthy men at low levels. PSA blood test results are reported as nanograms per milliliter or ng/mL. Results under four ng/mL are usually considered normal. Results over 10 ng/mL are considered high, and values between four and 10 are considered borderline. The higher the PSA level, the more likely the presence of prostate cancer. Men with a high PSA result are advised to have a biopsy, to determine whether or not cancer is present.

When the researchers measured PSA levels, they discovered that the likelihood of having HGPIN rose with increasing PSA concentrations. More African-American men than white men had evidence of this precancerous condition at every PSA level, even when the PSA level was less than 4.0.

"HGPIN right now is considered the pre-invasive stage of prostate cancer," says David Bostwick MD, clinical professor at the University of Virginia and medical director of Bostwick Laboratories in Richmond, VA. Bostwick co-authored the ACS’ book Prostate Cancer: What Every Man — and His Family — Needs to Know.

"HGPIN is clinically important in that it is one of the greatest risk factors for prostate cancer. And so this article breaks new ground in addressing the issues of HGPIN and its incidence in black and white Americans," Bostwick says.

It is also important to pay attention to the rate of change in PSA from year to year when values are less than 4.0, he says. Ultimately, patients should discuss the results and options with their physicians to understand the meaning of the test results and what follow-up would be best, says Bostwick.

Fowler acknowledges the need to interpret his data with caution. Gerald Chodak, MD, clinical professor of surgery at the University of Chicago, expresses similar concerns about the study results.

"The suggestion of the paper is that HGPIN is more common in black men," says Chodak. "But [the authors] haven’t proven that it’s not because of [unidentified] cancer (missed by the biopsy needle). Instead, the message might be, if you’re looking for prostate cancer, looking for it earlier may be more successful than looking for it later."

Fowler is continuing to follow the men in this study in an effort to solve the puzzles presented by prostate cancer.

The incidence of prostate cancer is much higher in African Americans than whites, and the death rates are more than twice as high. "I’ve tried to demonstrate what a burden this disease is," Fowler says. "It’s a burden in any population, but the burden in the black population is really something. So I always emphasize the racial differences because doctors need to know that prostate cancer in black men [needs greater attention]."