Geriatric predictors of response and adverse events in older patients with cancer treated with immune checkpoint inhibitors: A systematic review

Background: Immunotherapy with checkpoint inhibitors (ICI) has improved cancer treatment in recent years. Older and frail patients are frequently treated with ICIs, but since they have been underrepresented in previous clinical trials, the real impact of ICI in this patient group is not well defined. The aim of this systematic review was to evaluate the evidence for associations between geriatric impairments and treatment outcomes in older patients with advanced and metastatic cancer treated with ICIs. Methods: A systematic search was conducted in PubMed, Cochrane Library, Embase, and Web of Science for relevant articles published before June 2022. Studies investigating the association between impairments in at least two geriatric domains and treatment outcome were considered eligible. Data extraction and risk of bias assessment using the QUIPS tool was performed independently by two investigators. Results: A total of nine studies were included. Median sample size of the studies was 92 patients (interquartile range (IQR) 47-113), with a median of 26 frail patients (IQR 21-35). Five studies investigated disease-related and survival outcomes, and two of them found a statistically significant association between geriatric impairments and either survival or disease progression. Eight studies investigated toxicity outcomes, and two of them showed a statistically significant association between geriatric impairments and immune-related adverse events (irAEs). Few studies suggested a relation between geriatric impairments and worse clinical outcomes. Conclusions: Only a few studies have investigated the association between geriatric impairments and treatment outcomes and these studies were small. Older patients with geriatric impairments seem to be more likely to experience irAEs, but larger studies that include frail patients and use geriatric screening tools are required to confirm this association. These studies will be essential to improve the development of specific strategies to deal with frail patients.