Headache reporting in oncology trials depends on the demographics of the study population

Abstract

Background/Aim: The frequency of adverse events (AEs) in clinical trials without control arms is difficult to interpret. Materials and Methods: This is a systematic literature review of AEs reported from the placebo arms of randomized cancer trials in PubMed between 2008 and 2020. Results: We found 80 placebo patient cohorts in 73 publications, describing 17,968 subjects who received placebo. Headaches were reported in 35 patient cohorts with an average frequency of 12.3% (+/– SD=8.0, range=0.4-34.1), and were more common in cohorts with a median age between 45 and 50 years, with higher performance status, and breast cancer (average 29.8% +/– SD=6.1). AEs leading to discontinuation were reported in 5% of cohorts (+/– SD=5.1, range=0-22.7). Conclusion: Considering covariates allows more accurate interpretation of the observed AE frequencies in cancer trials.