Neuropsychologic Impact of Standard-Dose Systemic Chemotherapy in Long-Term Survivors of Breast Cancer and Lymphoma

Abstract

Data from this study support the hypothesis that systemic chemotherapy can have a negative impact on cognitive functioning as measured by standardized neuropsychologic tests and self-report of memory changes. However, analysis of the Neuropsychological Performance Index suggests that only a subgroup of survivors may experience long-term cognitive deficits associated with systemic chemotherapy.

Neurocognitive function in head and neck cancer patients prior to treatment

“…The lack of strong associations between performance on neuropsychological tests and self-reported neurocognitive function is not uncommon [30][31][32][33]. This apparent disparity has resulted in polarizing views among researchers and clinicians in the field about which is the most valid and clinically useful measure.…”

Cognitive effects of Tamoxifen in pre-menopausal women with breast cancer compared to healthy controls

“…It is also important to note that the researchers included both pre-and peri-menopausal women in their study, further limiting the conclusion that TAM, as opposed to menopause, had affected cognition. Lack of control for menopausal status is also characteristic of other studies [3,4].…”

“…Since chemotherapy itself may have detrimental cognitive effects in breast cancer patients [22][23][24], and significant differences were not obtained on these measures when TAM and chemotherapy users were compared to survivors who had only received chemotherapy, it is difficult to conclude that any cognitive difficulties could be solely attributed to TAM. Another study comparing high-and standard-dose chemotherapy treatments found no cognitive differences between TAM and no TAM subgroups of patients on any measure in a comprehensive test battery [3], but only 4 of the women tested were current users of TAM, rendering this finding similarly inconclusive.…”

“…In addition, TAM readily crosses the blood-brain barrier, and given the ubiquity of estrogen and its receptors in the nervous system, could potentially have effects on the cognitive abilities of users. This possibility has not been systematically studied; previous research has overlooked important confounding factors, especially the menopausal status of female study participants [3][4][5] and the concurrent influences of chemotherapy on cognitive performance [3][4][5][6].…”

“…Prior studies investigated TAM in addition to, or as a factor involved in the cognitive effects of chemotherapy [3][4][5][6], and therefore only provide exploratory suggestions regarding its role in patients' cognitive performance. When compared to breast cancer survivors who had received neither chemotherapy or TAM, those who had received both were found to exhibit significantly more self-reported cognitive difficulties [6], and significantly lower scores on verbal working memory [5], verbal learning, visual memory, and visuo-spatial ability [4] tasks.…”