PITTSBURGH, Jan. 14 -- Black and white women with same-stage breast cancer see largely similar outcomes when their treatment and follow-up care are appropriate for their individual disease conditions, suggesting that physiological responses to treatments are not responsible for poorer outcomes among blacks. These findings are reported in a review paper by University of Pittsburgh researcher James J. Dignam, Ph.D., and published this week in the January-February issue of CA: A Cancer Journal for Clinicians, a journal of the American Cancer Society.
The review covered historic and recent research on breast cancer prognosis among black and white women, including investigations of clinical, pathologic, social, economic and demographic factors that may contribute to poorer outcomes for blacks.
"Results of this review suggest that treatments for breast cancer have the same results in black women as they do in white women at the same stage of disease when administered according to expert consensus, and that the reasons for blacks' poorer prognoses lie elsewhere," said Dr. Dignam, research assistant professor in the University's Graduate School of Public Health, and biostatistician for the National Surgical Adjuvant Breast and Bowel Project (NSABP).
Dr. Dignam's review shows that the most important determinant of ultimate outcome in breast cancer patients is the stage of cancer at diagnosis, and blacks are more often diagnosed at a more advanced stage than are whites. Dr. Dignam suggested that possible reasons for this late diagnosis may be less access to or utilization of health care resources that would result in earlier detection, or more aggressive forms of the disease among black women.
"The bottom line is, early detection and appropriate follow-up therapy could appreciably reduce the disparity in outcome between black and white breast cancer patients," said Dr. Dignam. "Also, it is imperative that established therapies be uniformly delivered to all patients in accordance with their anticipated clinical prognosis."
When patients of the same stage are compared across racial lines, black women more often show characteristics associated with poorer prognosis, such as larger tumor size, greater nodal involvement and estrogen receptor negative tumors, the study shows. Even obesity, found to be more prevalent among black breast cancer patients, is associated with a more advanced stage, possibly due to obesity's effect on estrogen, which can accelerate disease progression.
When national guidelines are followed, such indicators of poorer prognosis might call for more aggressive treatments, such as chemotherapy in addition to or instead of tamoxifen, according to Dr. Dignam. But some studies show that black women with these indicators are not undergoing the appropriate therapies. Studies in some urban hospitals, which are likely to treat the bulk of black breast cancer patients, have a greater rate of late-stage diagnosis as well as a higher degree of nonstandard care, including less frequent post-surgical radiation therapy and diagnostic tests used to choose appropriate therapy.
"Certain aspects of care differed according to factors such as age and race, with older and black patients less frequently receiving treatment in accordance with recommended guidelines," said Dr. Dignam.
When treatment was administered, studies show that black women were much more likely to have received total mastectomy rather than lumpectomy with radiation therapy in cases where either procedure would have been acceptable.
"One study showed frequency of breast-conserving surgery to be related to higher income and education, but in fact the relationship between blacks and total mastectomy may have many causes, including an institution's lack of resources to provide adequate radiation therapy, and patient or physician preference," Dr. Dignam said.
Conversely, studies focusing on settings where national treatment guidelines were followed show similar outcomes between black and white patients at the same stage of disease, and roughly equal survival rates.
In an effort to foster better quality care across racial lines, the NSABP and other clinical trial groups have begun to encourage participation by blacks in randomized clinical trials.
"Encouragement by black scientists and community leaders would have immeasurable results in increasing the numbers of black women participating in these trials," Dignam said. "This in turn would help both the patients and the scientific community in its ability to assess the important public health question of why black women with breast cancer have a poorer survival rate than do white women."
This study was funded by grants from the National Cancer Institute and the American Cancer Society.
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