Mindfulness-based interventions and cognitive function in cancer survivors: a systematic review and meta-analysis

Abstract Background: Deterioration in cognitive function is common among cancer survivors undergoing treatment. These problems may persist for several years after completion of treatment and can adversely affect cancer survivors' treatment adherence and quality of life. The cause of cognitive changes in cancer survivors is unclear, although it is likely a complex interaction of disease-related, treatment-related, and psychological factors. Mindfulness-based interventions (MBIs) are one promising intervention for cancer survivors to alleviate unwanted and burdensome side effects, including disruptions in cognitive function. The aim of the current review was to synthesize the literature on MBIs and cognitive function in cancer survivors. Methods: We searched five databases from inception on May 27, 2021 (original search), and May 4, 2022 (updated search): PubMed, MEDLINE Ovid, EMBASE Ovid, PsycInfo Ovid, CINAHL EBSCO, and Web of Science. Articles were screened at the abstract and full-text level by two reviewers. Results: A total of 1916 records were retrieved, and 24 unique studies met the inclusion criteria. There was significant variability across studies regarding type of MBIs investigated, types of cognitive outcome measures used, and study assessment timelines. Eleven studies were included in a meta-analysis of self-reported cognitive function, significantly favoring MBIs over inactive controls (ie, usual care) (standardized mean difference = 0.86; 95% confidence interval = 0.32–1.41). A similar model, including four studies, compared MBIs with active controls (ie, music listening, metacognition treatment, fatigue education and support, walking program); this model also demonstrated a statistically significant pooled effect (standardized mean difference = 0.61; 95% confidence interval = 0.23–0.99). Owing to a small number of studies, meta-analysis could not be completed for objectively assessed cognitive function; a narrative summary for this outcome revealed mixed results. Conclusions: MBIs demonstrated evidence for improving cognitive function among cancer survivors and particularly self-reported cognitive function. However, most studies demonstrated a high risk of bias and significant concerns regarding study quality. Further research is needed to determine the effects of MBIs on both self-reported and objectively assessed cognitive function for cancer survivors, as well as optimal intervention structure and timing.