Cognitive Effects of Chemotherapy-Induced Menopause in Breast Cancer

Abstract

This study examined whether chemotherapy-induced menopause affects cognitive functioning in women with early breast cancer. The neuropsychological performance of 121 breast cancer patients (age M = 49.62, SD = 8.11, range = 25.25–67.92) treated with chemotherapy was assessed pre-chemotherapy, as well as 1, 6, and 18 months post-chemotherapy completion. Linear mixed modeling was used to evaluate the data. Type of menopause (pre, chemotherapy-induced, and post menopause) was found to significantly interact with cognitive performance on two cognitive variables. Specifically, chemotherapy-induced menopausal women did not show any significant changes in performance on an abstract reasoning task, while the pre-menopausal and post-menopausal groups significantly improved over time. A significant interaction on a test of finger dexterity and coordination was also found, although inspection of the results indicated that this was due to a significant improvement in the pre-menopausal groups at 6 months post chemotherapy. After chemotherapy most cognitive variables showed improvements over time, although two indicators of verbal memory showed significant declines immediately after chemotherapy, with improvement by 18 months post completion. The current study found little evidence to suggest that chemotherapy-induced menopause broadly affects cognitive functioning after treatment administration. However, longer follow-up assessments are warranted to assess the long-term effects of combined chemotherapy and endocrine treatment.

Keywords:

• Induced menopause
• Neurotoxicity
• Memory
• Chemotherapy

Acknowledgments

This research was generously supported from various sources: The Wesley Research Institute (200320), the Cancer Council of Queensland and the National Breast Cancer Foundation (406900), and the Australian Research Council (LPO669670). We would like to thank Drs Toni Jones, Donna Spooner, and Elena Moody for their input in the design and implementation of the study. Also, thank you to all oncologists, surgeons, and research nurses who helped in the recruitment process, and the research assistants involved in recruitment and data collection. The authors would like to thank Professor Kerrie Mengersen and Dr Jahar Choudhury for their statistical advice. Finally, the authors would also like to sincerely thank all the women who participated in the study at such a distressing period in their life. No conflicts of interest were identified by the authors.