Tamoxifen is commonly administered to women with breast cancer. It is an ant-estrogen that slows or prevents the recurrence of breast cancer in women who have hormone receptor positive breast cancers. A new study has reported that it may cause cognitive decline. The findings were published online on June 23 in the journal Menopause.
The study authors note that endocrine therapy is commonly used—and often for many years—in women with breast cancer. However, they explain that little is known about the effect of long-term tamoxifen use on cognitive function. Therefore, they evaluated cognitive function approximately three years after diagnosis in postmenopausal women with breast cancer who were treated with tamoxifen.
The investigators accessed data from women who underwent breast cancer surgery with or without radiotherapy, women who received tamoxifen, and healthy controls. They administered neuropsychological tests to the women. In addition, the women completed questionnaires regarding 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 a total of 107 (tamoxifen group: 20 women; surgery/radiotherapy group: 43 women; healthy control group: 44 women). The women in the tamoxifen group had received tamoxifen for an average 18.6 months (range: 15-79 months); they performed worse on verbal memory than the surgical operation/radiotherapy group and the healthy control group. Participants in the adjuvant tamoxifen group performed worse on measures of fluency than the healthy controls. In addition, women in the tamoxifen group reported worse cognitive function than women in the surgery/radiotherapy group or the healthy control group.
The authors concluded that their findings provide insights into cognitive function in women who receive long-term 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. They noted that cognitive domains that rely on verbal abilities (verbal memory and fluency) appear to be at risk for deterioration after treatment with tamoxifen.
Take home message:
As with any medication, risks and benefits exist. Thus, if you are on long-term tamoxifen therapy, discuss this study with your physician.