The valve of SHOX2 and RASSF1A gene methylation in bronchoalveolar lavage fluid in the diagnosis of lung cancerA protocol for systematic review and meta analysis

IntroductionThe incidence of lung cancer worldwide has been increasing in recent years, and the latest cancer data published by the WHO International Agency for Research on Cancer in 2021 shows that lung cancer remains the cancer with the highest mortality rate. The sensitivity of early screening methods for lung cancer is not ideal. Because early lung cancer is mostly located in nodules with a diameter of 1 cm, it is difficult to obtain a definite pathological diagnosis from living tissue specimens. Therefore, it is necessary to find less invasive and effective tests to help detect lung cancer early. Therefore, the purpose of this systematic review (SR) and meta-analysis will be to analyze and explore the correlation between promoter methylation of SHOX2 and RASSF1A genes and lung cancer, and to provide a reference for early clinical diagnosis. Methods and AnalysisThe relevant literature will be comprehensively searched in 4 international electronic databases (PubMed, Cochrane Library, EMBASE and Web of Science) and 4 Chinese electronic databases (CNKI, VIP, Wanfang, Chinese Biomedicine). We only included studies from inception until publication in May 2022. The primary outcome measure was the methylation rate of the SHOX2 and RASSF1A gene promoters in lung cancer tissue and normal lung tissue in the control group in lung cancer patients. Secondary outcome measures included methylation rates of promoters of SHOX2 and RASSF1A genes in different tissue samples. Two reviewers will conduct independent research selection, data extraction, data synthesis and quality assessment. The assessment of bias risk and data synthesis will be conducted using Review Manager 5.3 software. The Cochrane Collaborations Bias Risk Assessment Tool (QUADAS) will be used to assess the quality of the individual studies included. DiscussionThis systematic review will help to clarify the correlation between PROMOTER methylation of the SHOX2 and RASSF1A genes with lung cancer, providing clinical evidence for early clinical diagnosis. Trial registration numberCRD42022330609 (PROSPERO)