Cognitive function after the initiation of adjuvant endocrine therapy in early-stage breast cancer: an observational cohort study

Abstract

Purpose: This report examines cognitive complaints and neuropsychological (NP) testing outcomes in patients with early-stage breast cancer after the initiation of endocrine therapy (ET) to determine whether this therapy plays any role in post-treatment cognitive complaints.

Patients and methods: One hundred seventy-three participants from the Mind Body Study (MBS) observational cohort provided data from self-report questionnaires and NP testing obtained at enrollment (T1, before initiation of ET), and 6 months later (T2). Bivariate analyses compared demographic and treatment variables, cognitive complaints, depressive symptoms, quality of life, and NP functioning between those who received ET versus not. Multivariable linear regression models examined predictors of cognitive complaints at T2, including selected demographic variables, depressive symptoms, ET use, and other medical variables, along with NP domains that were identified in bivariate analyses.

Results: Seventy percent of the 173 MBS participants initiated ET, evenly distributed between tamoxifen or aromatase inhibitors. ET-treated participants reported significantly increased language and communication (LC) cognitive complaints at T2 (P = .003), but no significant differences in NP test performance. Multivariable regression on LC at T2 found higher LC complaints significantly associated with T1 LC score (P < .001), ET at T2 (P = .004), interaction between ET and past hormone therapy (HT) (P < .001), and diminished improvement in NP psychomotor function (P = .05). Depressive symptoms were not significant (P = .10).

Conclusion: Higher LC complaints are significantly associated with ET 6 months after starting treatment and reflect diminished improvements in some NP tests. Past HT is a significant predictor of higher LC complaints after initiation of ET.

Conflict of interest statement

Authors' disclosures of potential conflicts of interest and author contributions are found at the end of this article.

© 2014 by American Society of Clinical Oncology.

Figures

Fig 1.

Flow diagram of participant enrollment from the Mind Body Study (MBS) cohort included in this article. HT, hormone therapy; NP, neuropsychological; T1, before initiation of endocrine therapy; T2, 6 months after initiation of endocrine therapy; T3, 12 months after initiation of endocrine therapy.

Fig 2.

Scatterplots examining the relationship between T2 Patient's Assessment of Own Functioning Inventory (PAOFI) language and communication (LC) score (raw score) and the change in age and intelligence quotient–adjusted neuropsychological (NP) psychomotor domain score for individual participants from T1 (before initiation of endocrine therapy) to T2 (6 months after initiation of endocrine therapy). An NP change score greater than 0 indicates improvement. Correlations reported are based on the log-transformed LC PAOFI score. (A) For the 51 participants who did not receive endocrine therapy, r = 0.00 and P = .98, indicating no significant relationship between higher LC complaints and the change in NP psychomotor function between T1 and T2. (B) For the 122 participants who received endocrine therapy, r = −0.19 and P = .04, indicating a significant relationship with higher LC complaints associated with smaller improvements in NP psychomotor function between T1 and T2.