Abstract
Hormone therapy is the mainstay of adjuvant treatment for hormone receptor positive (HR-positive) nonmetastatic breast cancer. We evaluated adjuvant hormone therapy (AHT) initiation among Medicaid-insured women aged 21-64 years with stage I-III HR-positive breast cancer. We used multivariable logistic regression to identify independent predictors of AHT initiation. Within 1 year of diagnosis, 68% (1049/1538) initiated AHT; by 18 months, 80% (1168/1461) initiated AHT. In multivariable analysis, women less likely to initiate AHT had more comorbidity (≥ 2 vs none: adjusted odds ratio (AOR) = 0.55; 95% CI = 0.32 to 0.97), more advanced disease (stage III vs I: AOR = 0.27; 95% CI = 0.18 to 0.39), and no radiation after breast conserving surgery (AOR = 0.15; 95% CI = 0.10 to 0.22). Race, age, and history of mental health disorders were not independently associated with initiation of AHT. Among initiators of AHT, 58% (604/1049) were adherent to treatment for the year after initiation. Despite comprehensive prescription coverage, only 39% (604/1538) received optimal AHT including prompt initiation and adherence for the year after treatment. Partnerships between Medicaid programs and cancer registries may help identify at-risk women and facilitate the implementation of quality improvement strategies.