Sins of omission: A meta-research study evaluating the omission of operability in published retrospective comparisons of surgery with stereotactic body radiotherapy in patients with early-stage non-small cell lung cancer

Abstract

IntroductionPatients receiving stereotactic body radiotherapy (SBRT) for early-stage non-small cell lung cancer (NSCLC) are typically inoperable, in concordance with guidelines that advocate surgical resection as preferred treatment for operable patients. This differential treatment allocation complicates retrospective comparisons of surgery with SBRT by introducing the potential for confounding by operability. MethodsPubMed was queried for manuscripts reporting primary data from retrospective comparisons of overall survival (OS) between patients undergoing surgery versus SBRT for early-stage NSCLC. Each manuscript was categorized for two outcomes: (1) whether treatment allocation was based on a determination of patient operability, and (2) whether a direct OS comparison between operable SBRT patients and surgically treated patients was included. Associations with variables of interest were measured with statistical significance prespecified at p < 0.10. ResultsFrom 3,072 manuscripts identified in our query, sixty-one analyses met screening criteria. Twenty-one (34 %) reported operability status influencing treatment allocation. These were more likely to be published in journals with a surgical focus (52 vs 20 %) and impact factor < 5 (81 vs 58 %), and to contain cohorts from institutional datasets (81 vs 55 %), and to have a radiation oncologist as first (43 vs 25 %) or senior (43 vs 28 %) author. Seven (11 %) manuscripts featured a direct OS comparison between SBRT and surgery. ConclusionNearly-two-thirds of peer-reviewed retrospective studies that have compared OS between surgery and SBRT for early-stage NSCLC lack information on patient operability status, and nearly 90% lack a direct comparison between operable SBRT patients and those receiving surgery.