Neurocognitive function of lymphoma patients after treatment with chemotherapy

Chemotherapy has been shown to cause brain changes and to compromise cognitive function in cancer survivors. Knowledge about this matter is of vital importance for good clinical practice and insights into neurological aging. However, most studies have been conducted among breast cancer patients. Less is known about the effects of chemotherapy on the cognitive function of lymphoma patients.

We studied patients with non-Hodgkin or Hodgkin lymphoma who had been treated with standard dose chemotherapy or with supplementary high dose chemotherapy when standard dose chemotherapy had been unsuccessful. Age- and sex-matched relatives and friends were invited to participate as control participants. All participants underwent a cognitive examination with a battery of validated neuropsychological tests.

Matching of patients with control participants was found to be successful. Regression analysis did not reveal worse cognitive functioning of patients (N = 106) compared to matched controls (N = 53) on the overall group level (All Bonferroni-Holm corrected p-values >0.05). However, a subgroup of 16% of patients had deviant performance according to a chance-corrected criterion based on Ingraham and Aiken's probability curves, i.e. 1.5 standard deviations below the norm on three of 14 tests. Exploratory analyses showed that this subgroup of patients was lower educated and had lower estimated premorbid intelligence.

Chemotherapy may compromise the function of the brain in a subgroup of lymphoma patients. We hypothesize protection of the brain by 'cognitive or brain reserve' as a possible explanation.