Evaluation of NID2 and CDO1 methylation for ovarian cancer screening

Ovarian cancer (OC) is a highly invasive disease with a poor prognosis, underscoring the importance of identifying specific biomarkers in early screening to enhance the overall survival of patients with OC. In this study, quantitative methylation‑specific PCR was used to investigate the methylation levels of the nidogen‑2 (NID2) and cysteine dioxygenase 1 (CDO1) gene promoters in peripheral blood samples from 72 patients with OC and 75 healthy individuals. The results revealed significantly higher methylation levels of the NID2 and CDO1 genes in patients with OC compared with those in healthy controls. NID2 methylation demonstrated a sensitivity of 70.83% and a specificity of 96.00% in predicting OC, whereas CDO1 exhibited a sensitivity of 90.28% and a specificity of 69.33%. The positivity rate of NID2 methylation was elevated in patients with stage III‑IV OC compared with those with stage I‑II OC and was higher in high‑grade serous carcinoma compared with that in ovarian clear cell carcinoma. Additionally, the positivity rate of CDO1 methylation could reach 84.6% in patients with stage I‑II OC. Furthermore, the methylation levels of NID2 and CDO1 exhibited a positive correlation with carbohydrate antigen 125 (CA125) levels. Combining the detection of NID2 and CDO1 methylation with CA125 significantly enhanced the sensitivity and specificity of OC detection compared with CA125 detection alone. In conclusion, enhanced methylation of the NID2 and CDO1 genes has emerged as an independent risk factor for OC development.