PHS study finds ethnic differences in treatment of prostate cancer

A new study from researchers in the Public Health Sciences Division finds that African-American men are 26 percent less likely to receive aggressive hormone treatment for early stage prostate cancer than their Caucasian peers.

Dr. Steven Zeliadt, a postdoctoral fellow working with Dr. Ruth Etzioni, led the analysis of more than 90,000 men with localized prostate cancer. It is the first study to show an increasing trend associated with ethnicity in initial treatment differences for this disease. The study, which tracked the patients from 1991 to 1999, adds to a growing body of evidence pointing to a racial gap in cancer care.

Zeliadt and colleagues found that the use of androgen-deprivation therapy — hormone treatments designed to lower levels of male hormones, like testosterone, to make prostate cancers shrink or grow more slowly — increased significantly as first-line therapy among white males in the late 1990s compared to African-American males. By 1999, more than 45 percent of Caucasian men opted for the hormone medications compared to around 36 percent of African-American men.

"There's definitely a difference in what treatment black and white men receive for localized prostate cancer," Zeliadt said.

Dubious benefit

The silver lining in this cloud of disparity? The hormone therapy may be popular, but it isn't proven to be the ideal treatment for early stage prostate cancer, and it impacts quality of life.

"Clearly, for men who have localized disease, it ultimately may be a benefit not to be overtreated," said co-author Dr. David Penson, a center-affiliated investigator, formerly at UW School of Medicine and now at USC's Keck School of Medicine/Norris Cancer Center. "This therapy has unclear benefits, but definitely has significant side effects."

Common reactions to the therapy include declines in sexual and mental functioning, depression, osteoporosis (weakening of bones), anemia (low red-blood count) and memory loss, among others.

"They're very powerful drugs," Zeliadt said. "For men with localized disease — 80 percent of men — it doesn't look like this therapy is leading to any benefit. So it might be appropriate that black men are getting less aggressive therapy, but the fact that the treatments are different between the races is suspect."

Prostate cancer is the most common form of cancer among men in the United States, and it is second only to lung cancer as the main cause of cancer-related deaths. Even though the survival rate for prostate cancer has increased dramatically during the past 20 years due to early detection with prostate-specific antigen (PSA) testing, the prostate cancer death rate is 50 percent higher for African-American males than Caucasian men.

The study, funded by the National Cancer Institute (NCI), utilized a database linking NCI's Surveillance, Epidemiology and End Results (SEER) registry with Medicare claims. Since all of the patients were enrolled in Medicare, a lack of health insurance was not a factor in treatment choice.

"Any time we see racial disparities for no apparent reason, it's not a good thing," Penson said. "There are differences in patterns of care not clearly explained by rational, scientific reasons. Is it because of preconceived notions on the part of urologists about worse outcomes for African-American men?"

Quality of care

Other studies looking at racial difference in cancer-survival rates have found African Americans and Caucasians often see different doctors based on distinct neighborhoods. The physicians who treat African Americans are less likely to be board-certified in a specialty and more often say they are unable to provide high-quality care or access important resources like diagnostic imaging.

The study was published in the December edition of the journal Urology. Co-authors included PHS researcher Dr. Scott Ramsey and Dr. Arnold Potosky of NCI's Cancer Control and Population Sciences Division. Zeliadt's pre-doctoral training grant was funded by NCI.

Plans for further analysis

Etzioni credits the center and her group's long-standing collaboration with NCI for making this study possible. "Even though this data set is publicly available, it's massive, and we really didn't have the resources to do the data processing," she said. "NCI created a tailor-made data set for us to do this analysis. Also, the fact that Fred Hutchinson supports an outcomes group makes us uniquely positioned to do these kind of studies."

Zeliadt and Etzioni next plan to analyze this data set to look at the cost implications of the treatment trends. In addition, Zeliadt and Ramsey are currently working on a large survey of prostate-cancer patients, their partners and physicians to examine the role of each in treatment choice.