Lead investigator Akhouri Sinha of the University of Minnesota says in previous studies the prostate tumors of African-America patients tended to be larger and at a more advanced stage, and black men had higher blood levels of prostate specific antigen -- a substance produced by the prostate that, at high levels, points to the possibility of prostate cancer.

All these criteria are interrelated and could be the result of delayed diagnosis or medical care, Sinha said.

Sinha selected preserved slices of tumors from 130 surgery patients and matched 25 black and 25 white patients according to age, Gleason grade -- a pathologist’s measure of how advanced a prostate tumor is, clinical stage of the tumors and PSA levels before prostatectomy, or prostate removal.

The study, published in Anticancer Research, has shown no evidence that the cancer is more aggressive in black men, however, African-American patients are not following up with their doctors as opposed to Caucasians, and this difference is highly significant.