Purpose: For breast cancer, guidelines direct the delivery of adjuvant systemic therapy on the basis of lymph node status, histology, tumor size, grade, and hormonal receptor status. We explored how race/ethnicity, insurance, census tract-level poverty and education, and hospital Commission on Cancer (CoC) status were associated with the receipt of guideline-concordant adjuvant systemic therapy.
Methods: Locoregional breast cancers diagnosed in 2004 (n = 6,734) were from the National Program of Cancer Registries-funded seven-state Patterns of Care study of the Centers for Disease Control and Prevention. Predictors of guideline-concordant (receiving/not receiving) adjuvant systemic therapy, according to National Comprehensive Cancer Network Guidelines, were explored by logistic regression.
Results: Overall, 35% of women received nonguideline chemotherapy, 12% received nonguideline regimens, and 20% received nonguideline hormonal therapy. Significant predictors of nonguideline chemotherapy included Medicaid insurance (odds ratio [OR], 0.66; 95% CI, 0.50 to 0.86), high-poverty areas (OR, 0.77; 95% CI, 0.62 to 0.96), and treatment at non-CoC hospitals (OR, 0.69; 95% CI, 0.56 to 0.85), with adjustment for age, registry, and clinical variables. Predictors of nonguideline regimens among chemotherapy recipients included lack of insurance (OR, 0.47; 95% CI, 0.25 to 0.92), high-poverty areas (OR, 0.71; 95% CI, 0.51 to 0.97), and low-education areas (OR, 0.65; 95% CI, 0.48 to 0.89) after adjustment. Living in high-poverty areas (OR, 0.78; 95% CI, 0.64 to 0.96) and treatment at non-CoC hospitals (OR, 0.68; 95% CI, 0.55 to 0.83) predicted nonguideline hormonal therapy after adjustment. ORs for poverty, education, and insurance were attenuated in the full models.
Conclusion: Sociodemographic and hospital factors are associated with guideline-concordant use of systemic therapy for breast cancer. The identification of modifiable factors that lead to nonguideline treatment may reduce disparities in breast cancer survival.