Timing and specificity of the cognitive changes induced by interleukin-2 and interferon-alpha treatments in cancer patients

Objective: Neuropsychological changes develop in patients treated by cytoki ne immunotherapy with interleukin-2 (IL-2) and interferon-alpha (IFN-alpha) . However, the time course of appearance of these effects remains unclear, and their precise nature is still incompletely characterized. The objective of this study was to assess and characterize the early cognitive changes i nduced by IL-2 and IFN-a in cancer patients at the end of the first week of treatment and to investigate the subsequent evolution of these changes. Me thods: The study was conducted in 47 cancer patients who received subcutane ous IL-2, administered alone (N = 17) or with IFN-alpha (N = 7), or IFN-alp ha alone, administered subcutaneously at low doses (N = 7) or intravenously at high doses (N = 16). An automated battery of neuropsychological tests ( Cambridge Neuropsychological Test Automated Battery) was used to measure re action time, spatial working memory, and planning tasks. Cognitive tests we re performed before treatment (day 1) and after 5 days (day 5) and 1 month of treatment. Results: On day 5, patients treated with IL-2 alone had impai red spatial working memory and lower accuracy of planning abilities. In con trast, patients treated with IFN-alpha did not show any impairment in perfo rmance accuracy in these tasks but showed longer latencies in the test of r eaction time. Most of these early alterations persisted at the end of the f irst month of treatment without any obvious sign of worsening. Conclusions: These findings suggest the existence of early differential neuropsychologi cal changes in patients treated with IL-2 and IFN-alpha.