Racial disparities in the use of radiotherapy after breast-conserving surgery: a national Medicare study

Abstract

Background: In prior studies, the use of standard breast cancer treatments has varied by race, but previous analyses were not nationally representative. Therefore, in a comprehensive, national cohort of Medicare patients, racial disparities in the use of radiotherapy (RT) after breast-conserving surgery (BCS) for invasive breast cancer were quantified.

Methods: A national Medicare database was used to identify all beneficiaries (age >65 years) treated with BCS for incident invasive breast cancer in 2003. Claims codes identified RT use, and Medicare demographic data indicated race. Logistic regression modeled RT use in white, black, and other-race patients, adjusted for demographic, clinical, and socioeconomic covariates.

Results: Of 34,080 women, 91% were white, 6% were black, and 3% were another race. The mean age of the patients was 76 +/- 7 years. Approximately 74% of whites, 65% of blacks, and 66% of other-race patients received RT (P < .001). After covariate adjustment, whites were found to be significantly more likely to receive RT than blacks (odds ratio, 1.48; 95% confidence interval, 1.34-1.63 [P < .001]). Disparities between white and black patients varied by geographic region, with blacks in areas of the northeastern and southern United States demonstrating the lowest rates of RT use (57% in these regions). In patients age <70 years, racial disparities persisted. Specifically, 83% of whites, 73% of blacks, and 78% of other races in this younger group received RT (P < .001).

Conclusions: In this comprehensive national sample of older breast cancer patients, substantial racial disparities were identified in RT use after BCS across much of the United States. Efforts to improve breast cancer care require overcoming these disparities, which exist on a national scale.

Figure 1.

Percentage radiotherapy use in (a) white patients versus (b) black patients is shown. Gray shading indicates that the sample size was too small to provide meaningful data.

Figure 2.

Absolute difference in the rate of radiotherapy (RT) use between white and black patients is shown. An absolute difference <0% indicates that the percentage of black women receiving RT was greater than the percentage of white women. Gray shading indicates that the sample size was too small to provide meaningful data.