Chemotherapy-related changes in cognitive functioning

The potentially detrimental effects of cancer and related treatments on cognitive functioning are emerging as a key focus of cancer survivorship research. Many patients with central nervous system (CNS) or non-CNS tumours develop cognitive problems during the course of their disease that can result in diminished functional independence and can continue well into the survivorship period. In recent years, growing attention is being paid to the potential adverse effects of chemotherapy on brain and cognitive function. This central neurotoxicity may manifest as both acute and delayed complications. Virtually all categories of chemotherapeutic agent have been associated with adverse neurological effects, including both acute and chronic encephalopathy. More subtle cognitive dysfunction has also been demonstrated and frequently manifests as diminished memory, executive function, attention and information processing speed. In this article on chemotherapy and cognitive functioning we will summarise knowledge on the incidence of cognitive deficits, the neuropsychological pattern and structural brain changes associated with chemotherapy, risk factors identified for developing neurotoxicity and underlying mechanisms as well as current treatment options to prevent or diminish the adverse effects of chemotherapy on cognition. We will focus on chemotherapy-associated cognitive problems in breast cancer patients, as these symptoms have been particularly well studied in this patient group. In addition, studies on chemotherapy and cognition in adult CNS cancer patients will also be discussed. In this group of patients chemotherapy may be associated with stabilisation or improvement of cognitive function due to better disease control, but may at the same time go hand in hand with CNS toxicity as a consequence of chemotherapy.