Cognitive sequelae of brain tumor treatment

The neurocognitive sequelae of anticancer treatment have received increasing attention especially among individuals with low-grade gliomas, primary central nervous system lymphoma and those undergoing prophylactic cranial irradiation for systemic malignancies. These groups are especially vulnerable because they often experience extended survival during which neurocognitive complications of therapy may cause more impairment than the tumor itself. The purpose of this review is to highlight recent clinical reports of neurocognitive sequelae among patients without significant central nervous system tumor burden and to describe the experimental studies which may explain the pathogenesis of the disorder.

The neurocognitive deficits among survivors of primary central nervous system lymphoma without residual tumor and pituitary tumors were reported recently. Both provide an opportunity to distinguish the effects of treatment from the effects of tumor. Moreover, animal studies demonstrate the negative consequences of radiation on hippocampal neurogenesis, learning and memory. The mechanism of impaired neurogenesis may be due to inflammation, which can be aborted with restoration of neurogenesis through the administration of non-steroidal anti-inflammatory agents.

If inhibition of neurogenesis is the basis of neurocognitive sequelae from irradiation and non-steroidal anti-inflammatory agents can restore neurogenesis then a clinical trial may be worthwhile to confirm this benefit in humans.