Abstract:Objective To investigate the expression of Short stature homeobox 2（SHOX2）and Septin 9（SEPT9）genemethylation in cervical lesions of varying severity，and to evaluate their application value in the diagnosis of cervical intraepithelial neoplasia grade 3（CIN Ⅲ）and cervical squamous cell carcinoma（CSCC）. Methods A retrospective analysis was performed on 112 patients who underwent cervical biopsy at the Gynecology Clinic of Affiliated Hospital of Nantong University from June 2021 to May 2022. According to histopathological results，the patients were divided into chronic cervicitis group（n=17），CIN Ⅰ group（n=24），CIN Ⅱ group（n=22），CIN Ⅲ group（n=27）and CSCC group（n=22）. DNA was extracted from cervical specimens，and after bisulfite conversion，methylation - specific polymerasechain reaction was performed for SHOX2 and SEPT9. The ΔCt value was calculated to assess the methylation level.Receiver operating characteristic（ROC）curves and area under the curve（AUC）were used to evaluate the diagnostic efficacy of SHOX2 methylation，SEPT9 methylation and their combined methylation in different cervical lesions.Results The methylation levels of SHOX2 and SEPT9 increased with the aggravation of lesion severity，and there were statistically significant differences in positive detection rates among the five groups（P<0.01）. The positive rates ofSHOX2 methylation in CIN Ⅲ and CSCC were 62.96% and 90.91%，respectively，while those of SEPT9 methylationwere 70.37% and 95.45%，respectively，and the combined detection reached 77.78% and 100.00%，respectively. ROC curves showed that the AUCs of SHOX2 methylation，SEPT9 methylation and their combined methylation for the diagnosis of CIN Ⅲ were 0.662，0.681 and 0.700，respectively，and the AUCs for the diagnosis of CSCC were 0.827，0.827 and0.870，respectively. Conclusion The methylation levels of SHOX2 and SEPT9 are closely related to the severity ofcervical lesions. Combined detection of the two genes exhibits high diagnostic efficacy in identifying CIN Ⅲ and CSCC.