Geographical Disparities and Factors Associated With the Decision to Decline Chemotherapy in Breast Cancer.

Purpose: Social determinants of health have been linked to treatment-related disparities in breast cancer. We analyzed data from a large national registry to explore factors related to accepting or declining recommended chemotherapy and whether patients' decisions vary geographically across the United States.

Methods: We used the National Cancer Database to study treatment decision making in patients with advanced breast cancer (American Joint Committee on Cancer clinical stage III-IV) between 2004 and 2017. We focused the analysis on patients who were recommended chemotherapy by their physicians but who declined this treatment. Multivariate logistic regression analysis was performed.

Results: A total of N = 215,284 patients with stage III and IV breast cancers were included. Patients in the New England region were more likely to refuse chemotherapy compared with the rest, with patients in the East South Central regions (AL, KY, MS, and TN) and West South Central (AR, LA, OK, and TX) noted to be least likely to refuse chemotherapy. Factors related to a higher rate of refusal by patients included older age > 70 years; hormone receptor-positive tumors; and having higher comorbidity. Patients identified as Hispanic, those who are privately insured, and patients at academic institutions were less likely to decline chemotherapy.

Conclusion: This analysis identified a significant difference in rates of refusal of recommended chemotherapy by geographical location, insurance status, and treatment facility after adjusting for known social determinants of health. Further understanding of the factors affecting treatment decisions would be important to improve the efficacy of care delivery in patients with cancer and reduce reversible causes of disparity.