Diagnostic Accuracy and Concordance of Self-Collected Cervical CDO1 and CELF4 Methylation Testing Compared With Physician Sampling for Endometrial Cancer Detection

PURPOSE To address the growing incidence of endometrial cancer (EC), noninvasive detection methods are needed. Although self-sampling is proven for cervical cancer screening, its utility for EC detection via methylation analysis lacks robust evidence. This study aimed to validate this approach by evaluating the concordance and diagnostic accuracy of CDO1 / CELF4 methylation testing in self-collected samples compared with clinician-collected samples. METHODS In this prospective cross-sectional study, paired self-collected (Evalyn Brush) and physician-collected cervical samples were obtained from women referred for hysteroscopy. CDO1 and CELF4 methylation levels were measured by qPCR. Method agreement was analyzed with Spearman correlation and Bland-Altman plots, and diagnostic performance was evaluated by the area under the ROC curve (AUC). RESULTS Analysis of 142 participants revealed high agreement between self- and physician-collected samples, with significant correlations ( CDO1 R = 0.79, CELF4 R = 0.76; P < .05) and Bland-Altman analysis confirming minimal bias ( P > .05 for both genes). Self and physician sampling showed comparable efficacy for EC detection via CDO1 / CELF4 methylation, with AUCs of 0.930 and 0.896, respectively. Methylation levels (ΔCt) differed significantly ( P < .001) between EC (n = 33) and non-EC (n = 109) groups, regardless of the collection method. The diagnostic performance remained consistently high across premenopausal and postmenopausal subgroups. CONCLUSION Self-collected vaginal samples for CDO1 / CELF4 methylation analysis demonstrate high agreement and diagnostic accuracy equivalent to physician-collected samples for EC detection. This self-sampling strategy represents a reliable, noninvasive, and patient-centric approach, showing potential for integration into future EC diagnosis strategies to improve accessibility and early detection. Future multicenter studies are warranted to validate its effectiveness in broader populations.