Duke Study Eliminates Treatment Differences as Reason for Higher Prostate Cancer Mortality in Blacks
DURHAM, N.C. -- A Duke University Medical Center study debunks suspicions that unequal health care is the root of higher death rates among black prostate cancer patients. The researchers recommend looking to biological differences and later diagnosis to resolve the disparity in survival between black and white patients.
Nationwide, prostate cancer is fatal twice as often for blacks as for whites; in North Carolina, the mortality rate for men is more than two and a half times that of white men, the highest in the country.
In a study reported in the July 15 issue of the journal Cancer, Duke researchers surveyed 231 men (117 black, 114 white) from 63 N.C. counties who had been diagnosed with prostate cancer between 1994 and 1995. The survey was designed to help determine whether a difference in treatment of the disease accounted for the state's high black mortality rate.
Lead author Wendy Demark-Wahnefried, Ph.D., said the study, plus statewide treatment data, effectively ruled out a difference in treatment options as the root of the disparity in mortality rates. Men who participated in the study reported having essentially the same choices for treatment. The phone survey further found that both black and white patients were equally satisfied with their cancer treatment, and that both groups cited their physicians as having the greatest influence on the choice of treatment. The patients' stage of disease largely dictated treatment options, the researchers said, showing adherence to accepted standards of care.
Patients in the study received treatment from one of 16 facilities in North Carolina. Researchers concluded that with one exception, hormonal therapy, black men and white men were offered the same treatment options for their prostate cancer, including surgery, radiation and other therapies, and the option of "watchful waiting," where the patient's disease is monitored, but not actively treated unless it progresses. Black men were offered hormonal therapy less often than white men, though the study did not determine a reason for the difference.
Since black men also are diagnosed at later stages, when the disease is much harder to treat, the researchers are now studying whether there are differences in screening practices among blacks and whites and reasons why black men may not be screened routinely.
"African American men may have different beliefs about prostate cancer," Demark-Wahnefried said. "Although they realize that they may be at increased risk for the disease, they may not personalize that knowledge. They may think they are only at average risk. We need to learn more about why these mortality rates are so high."
She said the researchers also are analyzing data collected from ongoing studies to determine whether genetic and environmental factors play a role in mortality rates among African-American men. They are looking at diet, occupation, lifestyle and family history, among other factors.
The study, funded primarily by the Committee for Urologic Research, Education and Development at Duke and the N.C. Department of Health and Human Services, was the collaborative effort of researchers from Duke, UNC-Chapel Hill and the state of North Carolina.