Racial disparities and trends in radiation therapy after breast-conserving surgery for early-stage breast cancer in women, 1992 to 2002.

OBJECTIVES: Clinical guidelines recommend that when breast-conserving surgery is provided as primary therapy for early-stage breast cancer, radiation therapy should follow. We do not know whether racial/ethnic disparities in this therapy exist and how disparities may have changed over time. DESIGN AND PATIENTS: We studied 89,110 women who were diagnosed with incident early-stage (American Joint Committee on Cancer stages I-II) breast cancer at > or = 20 years of age from 1992 through 2002 in 12 geographic areas of the National Cancer Institute's Surveillance, Epidemiology, and End Results (SEER) tumor registries. These women had no history of other cancers and received breast-conserving surgery. Of these subjects, 81,577 (91.5%) were Caucasians and 7,533 (8.5%) were African Americans.
RESULTS: From 1992 to 2002, the percentage of cases who received breast-conserving surgery without radiotherapy increased from 10.8% to 19.8% for Caucasian women and from 13.6% to 27.7% for African Americans. The gap between African American and Caucasian women slightly increased during this period. When data were controlled for patient and tumor characteristics, year of diagnosis, and geographic area, African American women were 24% less likely than Caucasians to receive the recommended therapy (95% confidence interval: 1.18-1.32).
CONCLUSIONS: Although current clinical guidelines recommend that women with early-stage breast cancer who are treated with breast-conserving surgery should have subsequent radiation therapy, the percentage of women who did not receive this regimen increased from 1992 to 2002. The gap between African American and Caucasian women has continued from 1992 to 2002.