Methylation Analysis Of SHOX2/RASSF1A In Plasma For Lung Cancer Diagnosis And Predicting The Prognosis

Objective:By comparing the differences in SHOX2/RASSF1A gene methylation levels in peripheral blood between lung cancer patients and patients with benign lung lesions and following up patients after lung cancer surgery for a short period of time,we initially investigated the correlation between SHOX2/RASSF1A gene methylation levels and lung cancer and the accuracy of lung cancer diagnosis,and to analyze the independent predictors of progression-free survival of lung cancer patients after surgery.Methods:In the first part,we conducted We conducted a comprehensive literature search in PubMed,EMBASE,Cochrane Library,and Web of Science in the March 2021,and the number of exposed and non-exposed individuals in the experimental and control groups in each study were summarized by Revman 5.3 software,and the odds ratio(OR)was combined,and the sensitivity and specificity of SHOX2 gene and/or combined with RASSF1A gene methylation test were investigated to evaluate the diagnostic value of SHOX2 gene methylation for the diagnosis of lung cancer.In the second part,SHOX2/RASSF1A gene methylation levels were measured by real-time fluorescence quantitative PCR in the preoperative plasma of patients in the experimental group before and after surgery and in the control group,and the value of SHOX2/RASSF1A gene methylation for lung cancer diagnosis was analyzed by comparing serum tumor markers and combining with histological pathological examination,and the value of SHOX2/RASSF1A gene methylation for lung cancer diagnosis was predicted by one-way survival analysis and multiple COX regression predicted the independent predictors of progression-free survival of lung cancer patients with postoperative disease.Results:In the first part,13 papers were finally included in this meta-analysis,and the results after combining the data were:(1)the incidence of SHOX2 gene methylation in lung cancer tissues of lung cancer patients was significantly higher than that in the control group(OR=37.89,95%CI:17.96-79.92,P<0.05);(2)the incidence of SHOX2/RASSF1A gene in lung cancer tissues of lung cancer patients methylation was significantly higher in lung cancer patients than in controls(OR=54.46,95%CI:17.58-168.69,P<0.05);(3)the results of subgroup analysis suggested that SHOX2 gene methylation was most likely to be detected in solid tumors(OR=65.58,95%CI:32.13-133.86),followed by alveolar lavage fluid(OR=39.30,95%CI:25.60-60.32),plasma(OR=16.68,95%CI:11.11-25.03),and the lowest detection rate was in pleural effusion(OR=5.51,95%CI:3.90-7.78);(4)in squamous lung cancer(OR=45.54,95%CI:30.85-95%CI:30.85-67.22)and small cell lung cancer(OR=82.46,95%CI:46.51-146.20)were detected significantly more than lung adenocarcinoma(OR=16.22,95%CI:11.87-22.15).In the second part,(1)the efficiency of SHOX2 gene methylation detection alone was significantly lower than that of SHOX2/RASSF1A gene methylation level detection in 12 preoperative samples of the experimental group(P<0.05);(2)the results of SHOX2/RASSF1A gene methylation level detection were in good agreement with the gold standard(Kappa valu=0.750);(3)Among the 11 samples in the experimental group,positive SHOX2/RASSF1A gene methylation levels were detected in 8 cases and significantly elevated serum tumor markers in 3 cases,but the difference was not statistically significant(P=0.063);(4)In the univariate analysis,patients with positive postoperative plasma SHOX2/RASSF1A gene methylation had a significantly higher risk of early disease progression than those with postoperative plasma SHOX2/RASSF1A methylation.patients with negative methylation of SHOX2/RASSF1A gene(Wilcoxon test:P<0.05);(5)in COX regression model analysis,stage could be an Independent predictor of early disease-free survival in lung cancer patients(HR=32.020,95%CI:1.196-857.186,P=0.039<0.05).Conclusions:(1)SHOX2 methylation is significantly correlated with lung cancer as a possible option for the diagnosis of lung cancer,and it is more recommended to combine multiple genes,such as RASSF1A and other gene methylation tests,to improve the sensitivity of detection;(2)in the face of different pathological types,when other adjuvant tests suggest a greater tendency toward squamous lung cancer or small cell lung cancer,the detection rate of SHOX2 methylation can be considered due to its higher detection rate.(3)in the face of different sample sources,solid tumor detection was the most efficient,pleural effsion was the least efficient,and alveolar lavage fluid and plasma detection were comparable and in between.However,due to the lag of solid tumor results and the invasive and intolerable nature of alveolar lavage fluid,plasma detection of SHOX2 methylation will likely have more room for development and application prospects.(4)The results of SHOX2/RASSF1A gene methylation level testing were in good agreement with the gold standard for lung cancer detection(histopathological examination);(5)In the univariate analysis,patients with positive postoperative plasma SHOX2/RASSF1A gene methylation had a significantly higher risk of early disease progression than those with negative postoperative plasma SHOX2/RASSF1A gene methylation.(6)Tumor stage could be an independent predictor of early disease-free survival in lung cancer patients in COX regression model.