Neurocognitive outcomes in primary CNS lymphoma (PCNSL)

Soon after primary CNS lymphoma (PCNSL) became identified as a treatable tumor, patients, their families, and the treating physicians became aware of the neurocognitive toll that survivors accrued. PCNSL has a public health impact because of its disabling effects on cognition, mobility, language, and adaptive skills. As the population ages, neurocognitive decline after PCNSL treatment is a major and growing problem. The initial suspicion that the incidence of PCNSL is increasing has been confirmed by epidemiologic data. Furthermore, the increasing incidence is not explained by HIV infection, improved diagnostic techniques, or by an overall rise in brain tumors. PCNSL’s incidence is even higher in vulnerable individuals such as patients with HIV infection, patients who have received organ transplants, and the elderly.1

At the time these first reports were published it was all too easy to conclude that the neurocognitive decline was due to the effects of ionizing radiation on the CNS. Clearly, brain irradiation has a neurocognitive risk and such declines were documented in patients who received prophylactic cranial radiation (PCI) for small cell lung cancer, and therapeutic radiation for glioblastoma and brain metastases.2–4⇓ …