Abstract
Background and Aims: The diagnosis of ductal carcinoma in situ (DCIS) has increased markedly in the U.S. from 4,800 in 1983 to 59,000 in 2005. Although racial differences exist in the detection, diagnosis, evaluation, and treatment for invasive breast cancer, the extent of disparity for DCIS is unclear. Because women with DCIS are at high risk for local recurrence or invasive disease, it is critical to determine the degree of treatment disparities among racial/ethnic groups. We examined racial/ethnic variation in adjuvant therapy in a cohort of 3,000 women diagnosed with DCIS between 1990 and 2001 and treated with breast conserving surgery in three geographically diverse health plans based in California and Massachusetts.
Methods: We reviewed medical records and abstracted information regarding DCIS treatment, demographic characteristics, and comorbidity. Stratified analyses and multinomial logistic regression were conducted.
Main Findings: After adjusting for age, diagnosis year, study site, and geocoded income, odds ratios suggest that minority women were as likely to undergo adjuvant radiation therapy as white women. Asian/Pacific Islander women were somewhat more likely to receive adjuvant tamoxifen therapy (adjusted OR, 1.3; 95% CI, 0.7–2.2) compared to white women; however, there was little difference between white women and Hispanic women (adjusted OR, 0.8; 95% CI, 0.4–1.7) or black women (adjusted OR, 0.9; 95% CI, 0.5–1.7). Black women were somewhat less likely than white women to undergo a combination of adjuvant tamoxifen and radiation therapy (adjusted OR, 0.6; 95% CI, 0.4–1.0). Combination therapy was used to a similar extent in whites, Hispanics and Asian/Pacific Islanders. In a subset of patients for whom we had pathology data, tumor size and histology were controlled for in the analysis of adjuvant radiation therapy; however, these results were generally similar to those of the whole cohort.
Conclusion: We found modest, though statistically insignificant, racial/ethnic differences in DCIS treatment. The similar use of adjuvant therapy by Asian, Hispanic, and white women is impressive and may be due to the general access to care in these managed care plans. The reasons for possible lower use of combined therapy among black women are unclear and require further study.
- Received September 11, 2008.
