A national sample of older breast cancer patients (aged 68 to 83 years) found substantial racial disparities in the use of radiotherapy (RT)bfollowing breast-conserving surgery (BCS) across much of the U.S., based on a recent study published yesterday in the early edition of Cancer.
Lead author Grace Li Smith, MD, PhD, a postdoctoral fellow in M. D. Anderson's department of radiation oncology in Houston, and colleagues reviewed 37,305 Medicare records of patients diagnosed with early stage breast cancer in 2003.
The researchers found that 34,024 of the women who underwent a lumpectomy for their breast cancer were white and 2,305 were black. Overall, 74 percent of the patients who received radiation therapy after their lumpectomy were white, compared to 65 percent of the black breast cancer patients receiving the same treatment.
"The use of radiation after lumpectomy is considered to be the standard of care for women with invasive breast cancer, as clinical trials have demonstrated that it both reduces the chance of recurrence and improves the chance of survival," said senior author of the study Thomas Buchholz, MD, professor in the department of radiation oncology at M.D. Anderson.
Smith and colleagues utilized claims codes to identify RT use and Medicare demographic data to indicate race. Logistic regression represented RT use in white, black and other minority patients and adjusted for demographic, clinical and socioeconomic variations.
Smith noted that the most unanticipated aspect of the study was the scale in which racial disparity varied throughout specific areas in the country.
The Pacific West, 72 percent (whites) vs. 55 percent (blacks); East South Central, 72 percent (whites) vs. 57 percent (blacks); and the Northeast, 70 percent (whites) vs. 58 percent were noted as areas with the highest degree of geographic racial disparities in RT treatment rates. However, in both the Mountain West and the North Central Midwest, little to no discrepancy in treatment rates were reported, with 76 percent vs. 74 percent and 74 percent vs. 72 percent, respectively.
"Although there have been smaller studies of racial disparities in breast cancer care, no prior research has examined the differences across the nation in the rates of radiation therapy after lumpectomy between whites and blacks," said Smith.
According to Smith, follow-up research in this field will include the study of specific reasons why black and white women are receiving RT at different rates, as well as evaluating the difference in radiation rates results in a difference in mortality and the study of other disparities possibly excising for other cancer treatment options.