Immunobiological and neural substrates of cancer-related neurocognitive deficits

In addition to neurocognitive deficits, cancer patients may also experience fatigue, mood disorders, sleep disturbance, and sexual dysfunction, all of which are factors that negatively affect both neurocognitive functioning and healthrelated quality of life. The exact mechanisms responsible for neurocognitive and behavioral symptoms in cancer patients are not well understood, challenging clinicians to develop effective treatments. Side effects related to systemic chemotherapy and radiotherapy have been extensively investigated in clinical trials, but the effect of cancer treatment on neurocognitive function is one of the less well-characterized experiences of the patient. Apart from the ability of chemotherapy to enter the brain across the blood-brain barrier, DNA damage and shortened telomere length resulting from chemotherapy, problems with neural repair such as the presence of apolipoprotein E4 alleles, and decreased neurotransmitter activity as potential mechanisms underlying neurocognitive deficits in cancer patients, problems with cytokine regulation might provide an important explanations of compromised neurocognitive functioning. This chapter will discuss how changes in levels of cytokines are associated with changes in neurocognitive functioning in cancer patients. © 2009 Springer US.