Is poor sleep quality associated with poor neurocognitive outcome in cancer survivors? A systematic review

Purpose: Cancer-related neurocognitive impairment and poor sleep are prevalent in cancer survivors and have a negative impact on their quality of life. This systematic review studies the association between sleep disturbance and neurocognitive functioning, as well as the potential positive effects of sleep interventions on neurocognitive functioning in cancer survivors. In addition, we aimed at determining the potential positive effects of sleep interventions on neurocognitive functioning in this population. Methods: Following PRISMA guidelines for reporting systematic reviews and meta-analyses, a comprehensive PubMed, Embase, PsycINFO, and CINAHL search was performed. Inclusion criteria were adult cancer survivors, self-reported or objective measures of neurocognitive functioning and sleep quality, or reports on the association between sleep and neurocognitive functioning. Results: Of the 4,547 records retrieved, 17 studies were retained for this review. Twelve studies were correlational, and five reported on interventions aimed at improving sleep quality. All studies that included self-reported neurocognitive functioning found that poorer sleep was associated with worse neurocognitive functioning. In four out of eight studies, poorer sleep was associated with objective neurocognitive impairment. Three out of five interventional studies showed neurocognitive functioning improved with improved sleep. Conclusions: While poor sleep in cancer survivors is associated with self-reported neurocognitive impairment, the association between poor sleep and objective neurocognitive impairment is less evident. Implications for Cancer Survivors: It is important that care providers are aware of the association between sleep and neurocognitive functioning and that improving sleep quality can be a way to decrease neurocognitive impairment in cancer survivors.