Cognitive function and discontinuation of adjuvant hormonal therapy in older breast cancer survivors: CALGB 369901 (Alliance).

PURPOSE: To investigate the effects of cognitive function on discontinuation of hormonal therapy in breast cancer survivors ages 65+ ("older"). METHODS: Older breast cancer survivors with invasive, non-metastatic disease, and no reported cognitive difficulties were recruited from 78 Alliance sites between 2004 and 2011. Eligible survivors (n = 1280) completed baseline interviews; follow-up was conducted annually for up to 7 years. Survivors with estrogen-receptor-positive (ER+) cancers who initiated hormonal therapy (n = 990) were included. Self-reported cognitive function was measured using the EORTC-QLQ30 scale; a difference of eight points on the 0-100 scale was considered clinically significant. Based on varying rates of discontinuation over time, discontinuation was evaluated separately for three time periods: early (<1 year); midpoint (1-3 years); and late discontinuation (>3-5 years). Cox models for each time period were used to evaluate the effects of cognition immediately preceding discontinuation, controlling for age, chemotherapy, and other covariates. RESULTS: Survivors were 65-91 years old (mean 72.6 years), and 79% had stages 1 or 2A disease. Overall, 43% discontinued hormonal therapy before 5 years. Survivors who reported lower cognitive function in the period before discontinuation had greater hazards of discontinuing therapy at the treatment midpoint (HR 1.22 per 8-point difference, CI 1.09-1.40, p < 0.001), considering covariates, but cognition was not related to discontinuation in the other periods. CONCLUSIONS: Self-reported cognitive problems were a significant risk factor for discontinuation of hormonal therapy 1-3 years post-initiation. Additional research is needed on the temporality of cognitive effects and hormonal therapy to support survivorship care needs of older survivors.

Duke Scholars

Author Harvey Jay Cohen Medicine, Geriatrics and Palliative Care