This racial difference in treatment may be one reason why black men are more likely to die from the disease, the study authors suggest. The paper appears in the April 2004 issue of the Journal of Urology.
Researchers compared treatments for Caucasian, Hispanic and African-American men from 1992-1999. Data from 142,340 men was obtained from the national Surveillance, Epidemiology and End Results registry, a population-based cancer registration system maintained by the National Cancer Institute.
The men were divided into categories based on whether they received watchful waiting or definitive treatment – which includes surgery, external beam radiation therapy or brachytherapy (in which high-dose radioactive seeds are implanted in the prostate). Black men with moderate grade cancers were 36 percent less likely than white men to receive treatment, and Hispanic men were 16 percent less likely than white men to receive treatment.
The racial disparity was even more pronounced among men whose tumors were aggressive. Black men with aggressive cancers were half as likely as white men with similar disease to receive treatment; Hispanic men were 23 percent less likely than white men to receive treatment for aggressive cancer. Men with this aggressive form of prostate cancer are significantly more likely to die from the disease without treatment.
"We know African-American men are more likely to die from prostate cancer. However, when they are diagnosed with the most aggressive cancers, they are less likely to receive definitive treatment. This could possibly impact the reported racial disparity in prostate cancer mortality," says lead author Willie Underwood, M.D., an assistant professor of urology surgery in the U-M Medical School. "While research has focused on a genetic cause for increased mortality in African-Americans, treatment disparities is something that could be addressed in the context of health policy. Equal treatment for equal disease is something that should be achievable."
While black men are often diagnosed with prostate cancer at a younger age and with a higher grade of disease, previously studies have shown that when adjusted for age and tumor grade, there is no racial difference in survival or recurrence rates.
Racial disparity in treatment improved among Hispanic men from 1992 to 1999, the researchers found. Hispanic men with prostate cancer were less likely than Caucasian men to receive definitive therapy in 1992, but by 1999 that difference was not statistically significant. For African-American men, however, that discrepancy persisted from 1992 to 1999. Throughout the study period, black men had the lowest odds of receiving definitive treatment.
"Studies of Hispanic men are highly relevant as they are one of the fastest growing ethnic groups in the country, and this is the first time such data have been presented for this group. While we observed that the disparity between Hispanic and non-Hispanic groups have narrowed, there were still significant differences by race. For example, Hispanics were more likely to undergo surgery than were Caucasian or African-American men," says senior study author John Wei, M.D., an assistant professor of urology in the U-M Medical School.
The Hispanic population saw a 75 percent increase in prostate cancer diagnoses from 1969 to 1991. While prostate cancer mortality rates among white men have decreased in recent years, the numbers of deaths from the disease have held steady for Hispanics.
About 220,900 men were diagnosed with prostate cancer in 2003.
In addition to Underwood and Wei, study authors are Sonya Demonner, a biostatistician at U-M; Peter Ubel, M.D., associate professor of internal medicine; Angela Fagerlin, a research investigator in internal medicine; and Martin Sanda, M.D., associate professor of urology and internal medicine.
Funding for this study came from the National Cancer Institute, the National Institutes of Health and the Robert Wood Johnson Clinical Scholars Program.
Reference: Journal of Urology, Vol. 174 Issue 4, pp. 1504-1507.
Additional contact:
Sally Pobojewski,
pobo@umich.edu
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The Journal of Urology