Delay discounting and adjuvant endocrine therapy adherence in hormone receptor-positive breast cancer

Oral endocrine therapy improves survival among hormone responsive breast cancer (HRBC) survivors; however, 30-70% of patients are nonadherent. One patient-centered factor that may impact adherence is delay discounting (DD), or the degree to which patients value future outcomes. In prior research, DD is robustly associated with maladaptive health behavior; but no work to our knowledge has examined delay discounting and medication nonadherence in breast cancer patients. Study 1 examined cross-sectional associations between DD and endocrine therapy nonadherence. Study 2 examined whether DD in the HRBC population is amenable to a brief intervention-episodic future thinking (EFT), in which participants preexperience future events.

In Study 1, HRBC survivors completed assessments of DD and endocrine therapy adherence (pill count and self-report). In Study 2, participants were randomized to engage in a brief behavioral intervention (EFT) or a control condition, and again completed assessments of DD.

Eighty nine female HRBC survivors completed Studies 1 and 2. Controlling for other known risk factors, greater DD was significantly associated with poorer pill-count but not self-report adherence. In Study 2, the EFT intervention significantly reduced DD when compared to control episodic thinking.

DD is associated with direct-observation (pill count) measures of endocrine therapy adherence in HRBC survivors, suggesting it is a potential therapeutic target for improving adherence. This target is also amenable to intervention with EFT. (PsycInfo Database Record (c) 2021 APA, all rights reserved).