Factors Associated With the Decision to Decline Chemotherapy in Patients With Early-stage, ER + /HER2-Breast Cancer and High-risk Scoring on Genomic Assays

We explore factors associated with the decision to decline chemotherapy in patients with early-stage breast cancer patients with high risk of cancer recurrence, using the National Cancer Database. Of N = 43,533 patients, 10.1% declined chemotherapy despite medical recommendation. Old age, black race and non-private insurance significantly predicted chemotherapy decline, highlighting under-treatment in minorities that have been historically marginalized by medicine. Introduction: The rate of refusal of chemotherapy ranges from 3% to 19%, but varies widely by patient profile and treatment setting. Using a large national registry, we explore factors significantly associated with the decision to decline chemotherapy in patients with early-stage, HR + /HER2- breast cancer (BC) despite high risk scoring on multigene sequencing analysis for OncotypeDX (ODX) or MammaPrint (MP), in which the survival benefit of chemotherapy is clear. Patients and Methods: Patients with HR + /HER2- BC and high risk scoring on ODX (score .05) were included in a multivariable logistic regression model. Results: N = 43,533 patients were included (88.7% ODX, 11.3% MP). A total of n = 4415 (10.1%) patients declined chemotherapy despite recommendation by the patient???s primary oncologist. Age 70 (OR: 3.46, 95% CI: 2.964.04, P < .001), black race (OR: 1.20, 95% CI: 1.07-1.36, P = .01), non-private insurance, lobular carcinoma histology (OR: 1.21, 95% CI: 1.09-1.35, P < .001), and tumor grade of I significantly predicted chemotherapy decline. Conclusion: Identifying and addressing many of the factors that contribute to under-treatment in minorities is to be key to reducing cancer disparity and improving equity in cancer care and outcome.