Assessment of Cognitive Function in Cancer Patients

Four decades of chemotherapy-induced cognitive dysfunction: comprehensive review of clinical, animal and in vitro studies, and insights of key initiating events

Cognitive dysfunction has been one of the most reported and studied adverse effects of cancer treatment, but, for many years, it was overlooked by the medical community. Nevertheless, the medical and scientific communities have now recognized that the cognitive deficits caused by chemotherapy have a strong impact on the morbidity of cancer treated patients. In fact, chemotherapy-induced cognitive dysfunction or 'chemobrain'  (also named also chemofog) is at present a well-recognized effect of chemotherapy that could affect up to 78% of treated patients. Nonetheless, its underlying neurotoxic mechanism is still not fully elucidated. Therefore, this work aimed to provide a comprehensive review using PubMed as a database to assess the studies published on the field and, therefore, highlight the clinical manifestations of chemobrain and the putative neurotoxicity mechanisms.In the last two decades, a great number of papers was published on the topic, mainly with clinical observations. Chemotherapy-treated patients showed that the cognitive domains most often impaired were verbal memory, psychomotor function, visual memory, visuospatial and verbal learning, memory function and attention. Chemotherapy alters the brain's metabolism, white and grey matter and functional connectivity of brain areas. Several mechanisms have been proposed to cause chemobrain but increase of proinflammatory cytokines with oxidative stress seem more relevant, not excluding the action on neurotransmission and cellular death or impaired hippocampal neurogenesis. The interplay between these mechanisms and susceptible factors makes the clinical management of chemobrain even more difficult. New studies, mainly referring to the underlying mechanisms of chemobrain and protective measures, are important in the future, as it is expected that chemobrain will have more clinical impact in the coming years, since the number of cancer survivors is steadily increasing.

The Kingston Geriatric Cognitive Battery

Dementing illnesses are thought to account for over 50% of all mental health problems among the elderly. The diagnoses and treatments of dementing illnesses are complex, and occupational therapists frequently are called upon to contribute to the multidisciplinary assessment of cognitive impairment. The Kingston Geriatric Cognitive Battery is a tool developed to assist therapists in evaluating demented patients. This article describes the Kingston Geriatric Cognitive Battery and provides data on its validity and rater reliability.

Cognitive impairment associated with adjuvant therapy in breast cancer

The purpose of this study was to determine whether cognitive function changes over time in women with breast cancer who received adjuvant therapy as compared to women with breast cancer who received no adjuvant therapy. Three groups of women (n = 46) were studied; groups 1 and 2 consisted of women with stage I or II breast cancer. Group 1 received chemotherapy and group 2 received chemotherapy plus tamoxifen. Group 3 consisted of women with ductal carcinoma in situ who received no chemotherapy or tamoxifen. Cognitive function was evaluated at three timepoints. Time 1 occurred after surgery and before chemotherapy initiation in groups 1 and 2. Time 1 for group 3 occurred post-surgery. Time 2 occurred within 1 week after the conclusion of chemotherapy for groups 1 and 2 and at a comparable time for group 3. Time 3 occurred 1 year after Time 2. Women who received chemotherapy plus tamoxifen exhibited deterioration on measures of visual memory and verbal working memory and reported more memory complaints. Women who received chemotherapy alone also exhibited deteriorations in verbal working memory. Conversely, cognitive function scores improved in women who received no therapy, indicating practice effects. In conclusion, adjuvant chemotherapy in women with breast cancer can be associated with deteriorations in memory and this may persist over time. The addition of tamoxifen may lead to more widespread memory deficits.

Cognitive function and reproductive hormones in adjuvant therapy for breast cancer: a critical review

Deterioration in cognitive function-particularly learning, memory, and attention-has been reported by women with breast cancer who receive adjuvant chemotherapy. Deficits in cognitive function reported by women with breast cancer are similar to those experienced by women as a consequence of natural or surgical menopause. The basis of these deteriorations may include reductions in reproductive hormone levels, particularly estrogens and progesterones, that occur as a result of adjuvant chemotherapy. This paper critically examines the literature related to the impact of adjuvant chemotherapy and reproductive hormone changes on cognitive function in women with breast cancer and suggests direction for future research in this area. The paper proposes a framework for investigation of the problem and discusses the challenges associated with the conduct of this research.