Background: Combined radio- and chemotherapy for primary CNS lymphoma (PCNSL) is associated with a considerable risk of long-term neurotoxicity. The impact of high-dose methotrexate (MTX)-based chemotherapy alone on cognition and quality of life (QOL) is controversial.
Objective: To assess the impact of the tumor itself and its treatment with high-dose MTX-based chemotherapy on long-term cognition and QOL in patients with PCNSL.
Methods: Prospective neuropsychological examinations and MRI were performed in patients with PCNSL who were in complete remission for more than 12 months after completion of chemotherapy. A QOL assessment was performed at long-term follow-up.
Results: Twenty-three patients were eligible. The median follow-up period was 44 months after diagnosis. In long-term follow-up, 22 (95%) of 23 patients showed either preserved or improved cognitive functions as compared with pretreatment and immediate posttreatment baseline assessment. One patient showed an isolated decline in psychomotor speed. Eleven (48%) of 23 patients displayed at least mild cognitive deficits at long-term follow-up not related to therapy. Nineteen (83%) of 23 patients reported a good QOL. MRI revealed confluent white matter abnormalities in eight patients that were not associated with cognitive decline.
Conclusion: In patients with primary CNS lymphoma (PCNSL) treated with a methotrexate (MTX)-based chemotherapy, no gross cognitive decline has to be expected as a long-term treatment effect. MTX-induced white matter changes apparent on MRI are not inevitably associated with cognitive impairment. Nevertheless, a substantial fraction of patients with PCNSL retain cognitive deficits as a residual symptom of the tumor.