Effect of Obesity on Perioperative Outcomes Following Lung Cancer Surgery: Protocol for a Meta-Analysis and Systematic Review.

Abstract

<h4>Background</h4>Surgical resection is the primary curative treatment for early-stage lung cancer-the leading global cause of cancer mortality, responsible for nearly 1 in 5 cancer deaths in 2022. Obesity is a global health concern that may influence surgical outcomes; yet, its impact on perioperative outcomes following lung cancer surgery remains controversial.<h4>Objective</h4>This protocol outlines a meta-analysis and systematic review to evaluate the association between obesity and perioperative outcomes in patients who underwent a lung cancer resection.<h4>Methods</h4>Observational studies related to patients with lung cancer who underwent surgical resection were searched in 5 English and 3 Chinese literature databases: PubMed, Embase, Cochrane Library, Web of Science, MEDLINE, Chinese National Knowledge Infrastructure, Wanfang, and the Chinese Biomedical Database. The search period for these 8 electronic databases was from inception to 2025. The PROSPERO database and the International Platform of Registered Systematic Review and Meta-Analysis Protocols (INPLASY) database were also searched. Qualified studies were screened and selected by 2 authors independently. The literature obtained were imported into NoteExpress to screen the titles and abstracts. After reading the full text of the remaining studies, the final number of studies were determined. Two reviewers independently extracted data from the included studies by using a predesigned data extraction tool. The Newcastle-Ottawa Scale was used to evaluate the quality of the research. The primary outcome of this study was to evaluate the postoperative mortality in people living with obesity undergoing lung cancer surgical procedures. The secondary outcomes were the postoperative complications, average length of stay, blood loss during the operation, and operation time in people living with obesity undergoing lung cancer surgical procedures. For dichotomous data, we plan to present results as risk ratios with 95% CIs. For continuous data, we will use mean difference with 95% CIs. The Review Manager software (version 5.4) will be used for the meta-analysis and statistical analysis. Sensitivity analysis and Egger test will be performed with Stata software (version 16.0).<h4>Results</h4>The results are not yet accessible because this is a protocol for a systematic review and meta-analysis. The protocol is registered in PROSPERO under the registration number CRD42025648330. By August 26, 2025, we completed the literature search of the 8 databases and completed the selection and extraction of data.<h4>Conclusions</h4>This study will synthesize existing evidence to clarify whether obesity is a risk factor for adverse outcomes or if it confers a protective effect, as suggested by the obesity paradox. These findings will guide clinical decision-making and improve perioperative care for obese people with lung cancer.<h4>Trial registration</h4>PROSPERO CRD42025648330; https://www.crd.york.ac.uk/PROSPERO/view/CRD42025648330.<h4>International registered report identifier (irrid)</h4>PRR1-10.2196/76315.