Many breast cancer survivors are on tamoxifen therapy to reduce the risk of recurrence. A new study adds to the growing evidence that the therapy can produce cognitive decline. The findings were published in the January 2015 edition of the journal Menopause.
The study authors note that tamoxifen therapy is widely used, often for many years. In breast cancer survivors; however, data is lacking regarding cognitive function after long-term use of the medication. Therefore, the evaluated the cognitive status approximately three years after diagnosis in postmenopausal women with breast cancer who were treated with tamoxifen.
The investigators collected data from women who underwent surgery with or without radiotherapy, women who received adjuvant (supplementary) treatment with tamoxifen, and healthy controls. The participants underwent neuropsychological tests, and completed questionnaires on health-related quality of life (Quality of Life Questionnaire Core 30 and Breast Cancer–Specific Quality-of-Life Questionnaire), menopausal symptoms (Functional Assessment of Cancer Therapy—Breast endocrine symptom subscale), and anxiety and depression (Hopkins Symptom Checklist).
The study group comprised 107 women participated (adjuvant tamoxifen group: 20 women; surgery/radiotherapy group: 43 women; healthy control group: 44 women). Women in the adjuvant tamoxifen group had received tamoxifen for an 18.6 months (range: 15-79 months). These women did not perform as well on verbal memory than the surgery/radiotherapy group and the healthy control group. Women in the adjuvant tamoxifen group performed worse on measures of fluency than the healthy controls. In addition, women in the adjuvant tamoxifen group reported worse cognitive function than women in the surgery/radiotherapy group or the healthy control group.
The investigators concluded that their results offer insights into cognitive function in women who receive long-term adjuvant tamoxifen treatment. By adding the surgery/radiotherapy group, they could control for the mental and physical influences of the diagnosis and treatment of breast cancer. Cognitive areas that rely on verbal abilities (verbal memory and fluency) appears to be at risk for deterioration after treatment with tamoxifen.
Take home message:
Most medical therapies have both benefits and risks. In view of this study and another past study. If you are on tamoxifen therapy, it would be prudent to discuss the benefits and risks of tamoxifen with your oncologist.