OBJECTIVES: Prolonged opioid use is common and is associated with lower survival rates in breast cancer survivors. We explored whether opioid use in elderly breast cancer survivors using adjuvant endocrine therapy (AET) regimens was affected by the prevalence of mental health comorbidity, and in turn, how this impacted survival in this population.

METHODS: This retrospective study analyzed 2006–2012 SEER-Medicare datasets, following patients for at least two years from the index date, defined as the first date they filled an AET prescription. The study included adult women with incident, primary, hormone-receptor-positive, stage I–III breast cancer. They were also first-time AET users, and fee-for-service Medicare enrollees continuously enrolled in Medicare Parts A, B, and D. The main independent variable was the clinical diagnosis of a mental health comorbid condition. We measured whether patients used opioids after the initiation of AET, and survival at the end of the study period.

RESULTS: A total of 10,773 breast cancer survivors were identified who began AET treatments, of which the commonly diagnosed incident cases of mental health comorbidities were depression (n=970) and anxiety (n=631) respectively. Using a propensity scores risk adjustment model, we found that opioid use was significantly higher in women with mental health comorbidity (OR=1.25 (95% CI: 1.04-1.50), even after accounting for pharmacological treatment of the mental health condition. Additionally, mental health comorbidity was also associated with a significantly increased hazard of mortality in this population (Hazard Ratio: 1.69 (95% CI: 1.28- 2.24), after accounting for pharmacological treatment of mental health comorbidity.

CONCLUSIONS: The presence of mental health comorbidity in breast cancer survivors significantly increases risk of opioid use in these patients to manage pain related to adjuvant endocrine therapy. Significantly increased mortality in this vulnerable group of survivors highlights the need for better management of comorbid mental health conditions in this population.