Effects of Endocrine Therapy on Cognitive Function in Patients with Breast Cancer: A Comprehensive Review

Abstract

Endocrine therapy forms the backbone of systemic therapy for the majority of persons with early and late-stage breast cancer. However, the side effects can negatively affect quality of life, and impact treatment adherence and overall oncological outcomes. Adverse effects on cognition are common, underreported and challenging to manage. We aim to describe the nature, incidence, risk factors and underlying mechanisms of endocrine therapy-induced cognitive dysfunction. We conducted a comprehensive literature review of the studies reporting on cognitive dysfunction associated with endocrine therapies for breast cancer. We also summarise prevention and treatment strategies, and ongoing research. Given that patients are taking endocrine therapies for longer durations than ever before, it is essential that these side effects are managed pro-actively within a multi-disciplinary team in order to promote adherence to endocrine therapy and improve patients’ quality of life.

Effects of aerobic exercise on neurocognitive function in postmenopausal women receiving endocrine therapy for breast cancer: The Exercise Program in Cancer and Cognition randomized controlled trial

“…Approximately two‐thirds of BC cases are postmenopausal at diagnosis and over 80% receive endocrine therapy (ET) 2 . CRCD is associated with ET in women with BC, 3 and compromises psychological well‐being, occupational achievement, decision making, self‐management, and cancer therapy adherence 4 . We previously reported that, compared to matched controls, postmenopausal women with BC receiving aromatase inhibitor (AI) therapy demonstrated poorer executive function at pre‐therapy that persists through the first 18 months of therapy.…”

Cognitive impairment after cancer treatment: mechanisms, clinical characterization, and management

“…Endocrine therapies have been shown to increase both subjective cognitive complaints and objective cognitive testing 85. Current evidence shows that the deleterious effects of endocrine therapies may predominantly affect verbal memory and processing speed, rather than global cognitive deficits 86. Several studies suggest that verbal memory is mostly affected in endocrine therapies 87.…”

Design and methods of the mobile assessment of cognition, environment, and sleep (MACES) feasibility study in newly diagnosed breast cancer patients

“…Advances in cancer detection and treatment have increased the average five-year survival rate for breast cancer patients to 90% 1 . Endocrine therapy (ET) such as tamoxifen and/or aromatase inhibitors reduces the risk of breast cancer recurrence in patients with estrogen receptor positive tumors (60% of breast cancer) 2 , but is often accompanied by complaints of cognitive impairment (independent of chemotherapy) 3 – 5 . Endocrine therapy-induced adverse effects on cognition are common, clinically underreported, and challenging to manage.…”