COGNITIVE FUNCTION AND HORMONAL THERAPY ADHERENCE IN A COHORT OF OLDER SURVIVORS: CALGB 369901

摘要

Background: Adjuvant hormonal therapy is the standard of care for estrogen-receptor-positive (ER+) breast cancer survivors, but up to half of survivors do not adhere to recommended treatment (5 years+). Adherence may be more complicated in women older than 65 years (the majority of survivors) due to adverse effects of hormonal therapy, such as cognitive impairment. However, the relationship between cognitive function and hormonal therapy adherence is poorly understood. The objective of this study is to examine the relationship of cognitive function and hormonal therapy adherence over 5 years in older breast cancer survivors.Methods: A cohort of cognitively intact ER+, non-metastatic breast cancer survivors (65 years and older) that initiated hormonal therapy were recruited from 78 sites between 2004–2011 (n=909). Follow-up data were collected at 6 months and annually for up to 7 years. Cognitive function was self-reported using EORTC-QLC30. Group-based trajectory modeling determined groups based on the highest probability of membership and logistic regression was used to test associations with discontinuation of hormonal therapy before at least 5 years of prescribed medication use.Results: The mean cognitive score for survivors at baseline was 93.2 points (SD=12.3). Most breast cancer survivors were in early to middle stages of disease (i.e., stage 1=47.4%, stage 2a=31.4% and stage 2b-3=21.3%). Approximately 30% of women reported early discontinuation of hormonal therapy. Many women (42%) had high cognitive function that remained stable over time; more (49.1%) showed a phase shift (i.e., slight decline) in cognitive function with time. Only 9.2% of survivors showed a pattern of accelerated cognitive decline over time. Survivors with accelerated decline were more likely than those who maintained high function to discontinue hormonal therapy (OR 1.49: 95% CI, 0.88–2.55, p=0.14), controlling for age, stage and prior use of chemotherapy. Additionally, survivors who exhibited a phase shift in cognitive function were significantly more likely than survivors who maintained high function to discontinue hormonal therapy (OR 1.40: 95% CI 1.03–1.91, p=0.03), also controlling for age, stage and prior use of chemotherapy.Conclusions: Cognitive dysfunction is a relevant yet understudied side effect of hormonal therapy in older survivors and may affect the duration of medication adherence. Our preliminary results suggest that survivors with cognitive decline may play a role in early discontinuation of hormonal therapy in older survivors. This will be an important area for future research on temporality of these effects and has clinical implications for survivorship care.