Sarcopenia and the risk of adverse events in patients treated with immune checkpoint inhibitors: a systematic review

Background Sarcopenia has been associated with negative clinical outcomes in cancer patients, particularly response to treatment and survival. The exponential growth in the use of immune checkpoint inhibitors (ICIs) has led to an increase in the reporting of both adverse events in general (AEs) and immune-related adverse events (irAEs), which are unintended immune-related phenomenon that take place as a result of checkpoint blockade. However, there are no systematic reviews evaluating the relationship between sarcopenia and the risk of developing AEs and irAEs in cancer patients on ICI therapies. Methods PubMed, MEDLINE, Embase, Cochrane and grey literature, repositories, websites Open Grey, Google Scholar, and abstracts of major international congresses were searched up to April 2020 for observational studies on sarcopenia and both AEs and irAEs in patients treated with ICIs. Study quality was assessed with The Newcastle-Ottawa quality assessment scale. PROSPERO registration number: CRD42020197178. Results One hundred and thirteen discrete articles were identified. Seven studies were included after evaluation of the eligibility criteria. Important sources of heterogeneity including the specific cut-points defining sarcopenia, sample size, inclusion and exclusion criteria, treatment regimen, and baseline demographics were evaluated and accounted for accordingly. Conclusion Most of the included studies showed an increased risk of AEs with use of ICIs in cancer patients with sarcopenia, and in the majority of these, the increase was statistically significant. Due to the small number of available studies and the expanding use of ICIs, additional research is warranted.