The goal of the study is to determine what percentage of statistically significant survival gains for cancer treatments that have been reported in randomised trials are also consistent with a clinically insignificant gain. This study, published in prestigious journals between 2009 and 2019, is a cross-sectional analysis of reports of randomised clinical trials of cancer therapies that showed a statistically significant improvement in overall survival. The hazard ratio (HR) and upper 95% confidence limit for overall survival served as the primary outcome measure. Given the probable toxicity of oncologic therapies, we reasoned that an absolute survival benefit of 1.9% implied by an HR of 0.95 and 3.8% implied by an HR of 0.90 can be regarded clinically inconsequential.