Search

Background In cancer randomized controlled trials (RCT), alternative endpoints are increasingly being used in place of overall survival (OS) to reduce sample size, duration and cost of trials. It is necessary to ensure that these endpoints are valid surrogates for OS. Our aim was to identify meta-analyses that evaluated surrogate endpoints for OS and assess the strength of evidence for each meta-analysis (MA). Materials and methods We performed a systematic review to identify MA of cancer RCTs assessing surrogate endpoints for OS. We evaluated the strength of the association between the endpoints based on (i) the German Institute of Quality and Efficiency in Health Care guidelines and (ii) the Biomarker-Surrogate Evaluation Schema. Results Fifty-three publications reported on 164 MA, with heterogeneous statistical methods Disease-free survival (DFS) and progression-free survival (PFS) showed good surrogacy properties for OS in colorectal, lung and head and neck cancers. DFS was highly correlated to OS in gastric cancer. Conclusion(s) The statistical methodology used to evaluate surrogate endpoints requires consistency in order to facilitate the accurate interpretation of the results. Despite the limited number of clinical settings with validated surrogate endpoints for OS, there is evidence of good surrogacy for DFS and PFS in tumor types that account for a large proportion of cancer cases. [ABSTRACT FROM AUTHOR]

Spin, the misrepresentation of research findings, in clinical trial abstract has been shown to influence how oncologist rate a drug's efficacy. We searched PubMed for clinical trials published in ten key journals in 2017. Our primary objectives were to assess the frequency and manifestations of spin in the abstracts of those clinical trials that measured both overall survival and at least one surrogate efficacy endpoints. 124 trials were included for analysis. We found evidence of spin in 46 of 124 (37.1%, 95% CI 29.1%–45.9%) trial abstracts. Spin in the abstract results was most often due to authors emphasizing a statistically significant subgroup analysis (n = 6). Spin in the abstract conclusions was most often due to authors relying on a statistically significant surrogate endpoint to highlight the bioefficacy of the intervention (n = 17). Spin is prevalent in the abstracts of oncology clinical trials that measure OS and a surrogate endpoint. The conclusion sections of abstracts were most prone to contain spin. When OS was the primary endpoint, spin was primarily used to distract from the nonsignificant OS data. To mitigate unintentional hype for cancer therapies, we recommend authors structure their conclusions around patient-important outcomes. [ABSTRACT FROM AUTHOR]