Long-term decision regret surrounding systemic therapy in older breast cancer survivors: A population-based survey study

Introduction: Little is known regarding regret experienced by older breast cancer survivors surrounding the choice for adjuvant systemic therapy, which limits providers’ ability to optimally engage in the shared decision-making process. To address this, we evaluated endocrine therapy and chemotherapy decisional regret in a population-based cohort of older breast cancer survivors. Materials and Methods: Nationally comprehensive Medicare claims identified women age ≥67 living in the US with non-metastatic breast cancer diagnosed in 2009 and still alive in 2015. The Decision Regret Scale, a validated index that assesses regret regarding treatment decisions on a scale of 0 (no regret) to 100, was used to measure regret for endocrine therapy and chemotherapy approximately 6 years after diagnosis and was adjusted for sampling weight. Multivariable logistic regression adjusted for patient, demographic, and treatment characteristics identified predictors of endocrine therapy and chemotherapy decision regret. Results: Of the 480 respondents, 299 patients (61.1%) reported receiving endocrine therapy and 133 (27%) chemotherapy. The overall weighted decision-regret score was 17.2 (95%CI 13.6–20.8) for endocrine therapy and 17.7 (95%CI 12.1–23.3) for chemotherapy. Risk factors for higher endocrine therapy regret included white race (referent non-white race; estimate 12.8, 95%CI 3.0–22.7; P = 0.01) and post-graduate educational attainment (referent college education; 11.6, 95%CI 1.9–21.3; P = 0.02). The only risk factor for chemotherapy regret, albeit marginal, was age ≥75 (referent age 67–74; 12.0, 95%CI −0.1–24.2; P = 0.05) Conclusion: Overall, decision regret levels regarding systemic therapy in older breast cancer survivors are reassuringly low. However, further studies are needed to explore drivers of regret in certain vulnerable subgroups of patients.