Racial gap still seen in prostate cancer recurrence

San Francisco-Despite improvements in detection and treatment over the past 2 decades, African-American men remain at higher risk for recurrence of prostate cancer than Caucasian men. While factors such as initial PSA levels and disease severity are similar between the two racial groups, African-American men are 11% more likely than Caucasian men to have a biochemical failure after radical prostatectomy, according to a new study.

"We know that African-American men are disproportionately affected by prostate cancer compared to Caucasian men," study co-author Hadley Wood, MD, a resident at the Cleveland Clinic Glickman Urological Institute, told the Prostate Cancer Symposium. "What we do not know is why. The answer is still unknown and is probably multifactorial."

Racial disparities in prostate cancer outcomes have been acknowledged for many years, Dr. Wood said. In the past, disparate outcomes were attributed to factors such as less access to prostate cancer screening and care, less aggressive treatment, poorer prostate cancer screening outreach in minority communities, socioeconomic differences, cultural differences in attitudes toward the medical community and medical treatment, and potential differences in tumor biology. Some researchers have suggested that wider availability of PSA screening and greater awareness of the disease may have narrowed the survival gap.

The study results are clear, Dr. Wood said. During the early period, African-American men lagged behind their Caucasian counterparts in progression-free survival by 11% at 5 years after surgery: 67% for African-Americans and 78% for Caucasians (p=.0095). During the late period, African-American men lagged behind their Caucasian counterparts by the same 11%: 71% for African-Americans and 82% for Caucasians (p<.0001). The racial gap persisted despite significant and similar improvements in diagnosis, staging, and treatment for both groups of men.

The study found an overall decrease in age at diagnosis: 60 years during the late period compared with 63 years in the early period. Both groups had a higher rate of organ-confined disease in the late period: 76% versus 54% for African-Americans (p=.0001) and 71% versus 50% for Caucasians (p<.0001). Dr. Wood noted that African-Americans had a numerically higher rate of organ-confined disease in both periods despite similar Gleason scores on biopsy, clinical T-stage, and initial PSA levels, but the differences were not statistically significant.

"There is no doubt that there continues to be a socioeconomic gap between the two groups," Dr. Wood said. "We do not know if patients received the same degree of home support before and after treatment. We had no way to determine those factors in this retrospective analysis, even knowing that they can affect outcome. A growing body of literature also suggests racially based differences in tumor biology. Whatever the causes may be, this gap deserves more research."