Trends in adherence to NCCN guidelines for breast conserving therapy in women with Stage I and II breast cancer: Analysis of the 1998-2008 National Cancer Data Base.

Objective: To examine temporal trends in guideline adherence for breast cancer local therapy, by race/ethnicity, socioeconomic and insurance status.

Background: Treatment guidelines recommend breast conserving therapy (BCT) for women with small cancers, but have been unevenly applied. A better understanding of time-trends in guideline adherence may point to interventions for correction.

Methods: Patients with tumors ≤2 cm (n = 1,081,075) were identified from 1123 NCDB hospitals, dividing the interval 1998-2011 into 5 segments. Significant differences in rates of guideline adherence over time for race/ethnicity, quartiles of income, education, and insurance status were identified using Chi-square tests. Random effects logistic regression was used to compute odds ratios (OR) for the likelihood of guideline adherence controlling for sociodemographic and clinical characteristics, hospital type and region.

Results: Multivariate models revealed disparities in use of BCT for women ≤39 years (OR 0.49, 95% CI 0.48-0.50); for Asians (OR 0.67, 95% CI 0.65-0.69); for women in the lowest education quartile (OR 0.89, 95% CI 0.87-0.91); and for women in rural regions, (OR 0.79 95% CI 0.76-0.81). The largest radiotherapy disparity was for the oldest women (OR 0.37, 95%CI 0.37-0.38), and in rural regions OR 0.67, 95% CI 0.63-0.71. Over time, differences persisted in BCT use (for race, income, education, insurance type); and for endocrine therapy (by race and education).

Conclusion: There was mixed progress in reducing disparities in guideline adherence. These results are conservative, since the most favorable tumor stages were analyzed in the NCDB, which reflects higher quality of care than non-participating hospitals.