Black women are less likely than white women to receive radiation therapy after a lumpectomy, the standard of care for early-stage breast cancer, according to a new study by researchers at The University of Texas M.D. Anderson Cancer Center.
The study was presented Wednesday in advance of the American Society of Clinical Oncology (ASCO) Breast Cancer Symposium held this week in Washington, D.C.. It is the first U.S. study to examine racial disparities in radiation therapy, according to Grace Li Smith, MD, PhD, a postdoctoral fellow in M. D. Anderson's department of radiation oncology and one of the study authors.
For the retrospective cohort study, Smith and colleagues used Medicare claims to examine the treatment history of women aged 66 and older diagnosed in 2003 with early stage, newly diagnosed breast cancer. Of the 37,305 women who underwent a lumpectomy for their breast cancer, 34,024 were white and 2,305 were black. Overall, 74 percent of the white women received radiation therapy after their lumpectomy; in contrast, 65 percent of the black breast cancer patients received the same treatment.
"While there are some breast cancer patients, such as those over age 70, with significant co-morbidities for whom radiation would not be appropriate, this discrepancy remained consistent when specifically looking at patients under the age of 70,” said Thomas Buchholz, MD, professor in the department of radiation oncology and the study's senior author.
Perhaps the most unexpected aspect of the study was the magnitude of the disparity in specific areas of the country: the Pacific West, 72 (whites) vs. 55 percent (blacks); East South Central, 72 (whites) vs. 57 percent (blacks), and the Northeast, 70 (whites) vs. 58 percent (blacks), according to the researchers.
In the Mountain West (76 percent vs. 74 percent) and the North Central Midwest (74 percent vs. 72 percent), however, there was virtually no discrepancy in radiation rates between whites and blacks. That level of geographic non-disparity was also surprising and of great benefit for further research, Smith said.
"Until further research is conducted, we may only speculate about the underlying reasons why black and white women are not receiving radiation at the same rate. We don't know if fewer black women are receiving radiation simply because it is not offered to them, because they decline the treatment, or perhaps because they are unable to complete a whole course of treatment due to other health problems. These questions will be important subjects of future study. As a medical community, we need to identify and eliminate any obstacle prohibiting all women from receiving necessary care for their breast cancer,” the authors wrote.
Smith said her plans for follow-up research include evaluating the difference in radiation rates results in a difference in mortality, whether radiation patterns correlate with other illnesses secondary to breast cancer care and if there are disparities in other types of cancer treatment.
The Department of Defense Breast Cancer Research Program provided a grant, which supported the research in this study.