Survival outcomes following complete mediastinal lymphadenectomy or selective mediastinal lymphadenectomy in patients with stage I-IIIA non-small cell lung cancer: protocol for a systematic review and meta-analysis.

INTRODUCTION: Lung cancer remains the largest cause of cancer-related deaths worldwide. Surgical removal of non-small cell lung cancer (NSCLC) has the potential to achieve a cure, although there is ongoing debate regarding the significance of removing mediastinal nodes and the optimal extent of lymph node excision. The purpose of this research is to assess the survival outcomes in patients diagnosed with stage I-IIIA NSCLC who received either complete mediastinal lymphadenectomy (CML) or selective mediastinal lymphadenectomy (SML).

METHODS AND ANALYSIS: The protocol follows the guidelines recommended in Preferred Reporting Items for Systematic Review and Meta-Analysis Protocols, and this meta-analysis will be conducted in accordance with the standard methodology recommended by the Cochrane Collaboration and reported in accordance with Preferred Reporting Items for Systematic Reviews and Meta-Analyses 2020 guidance. We will conduct a comprehensive search for randomised controlled trials and non-randomised studies examining the effectiveness of CML compared with SML in patients with stage I-IIIA NSCLC. Two authors will perform a comprehensive search of the MEDLINE/PubMed, Embase, the Cochrane Library, CNKI, WanFang, Sinomed, VIP and Web of Science databases. There will be no restrictions on language or publication date, and the search will be conducted on 10 April 2024, with ongoing searches for new research. Reference lists will also be checked and pertinent journals will be hand searched. The primary outcomes include overall survival (OS) and disease-free survival (DFS), while the secondary outcomes consist of 1-year, 3-year and 5-year OS rates and 1-year, 3-year and 5-year DFS rates. Two independent reviewers will screen, extract data, assess quality and evaluate the potential for bias in the selected research, with a third acting as arbitrator. Subgroup analyses and sensitivity analyses are planned. The quality of the evidence will be evaluated using Grading of Recommendations Assessment, Development and Evaluation. Review Manager V.5.4 will be used for the analysis and synthesis process.

ETHICS AND DISSEMINATION: Ethical review and approval are not necessary for this study because it is based on a secondary analysis of the literature. The results will be submitted for reporting in a peer-reviewed publication.

STUDY REGISTRATION: Open Science Framework (https://doi.org/10.17605/OSF.IO/PN7UQ).