Discovery and technical validation of high-performance methylated DNA markers for the detection of cervical lesions at risk of malignant progression in low- and middle-income countries
Authors: Fackler Mary Jo , Pleas Madison , Li Youran , Soni Anushri , Xing Deyin , Cope Leslie , Ali Syed , Van Le Quang , Van Nguyen Chu , Pham Han Thi , Duong Long Minh , Vanden Berg Eunice , Wadee Reubina , Michelow Pamela , Chen Wenlong Carl , Joffe Maureen , Fjeldbo Christina Saetan , Lyng Heidi , Sukumar Saraswati 
Published: April 2024

Abstract
Background
Cervical cancer remains a leading cause of death, particularly in developing countries. WHO screening guidelines recommend human papilloma virus (HPV) detection as a means to identify women at risk of developing cervical cancer. While HPV testing identifies those at risk, it does not specifically distinguish individuals with neoplasia. We investigated whether a quantitative molecular test that measures methylated DNA markers could identify high-risk lesions in the cervix with accuracy.

Results
Marker discovery was performed in TCGA-CESC Infinium Methylation 450 K Array database and verified in three other public datasets. The panel was technically validated using Quantitative Multiplex-Methylation-Specific PCR in tissue sections (N = 252) and cervical smears (N = 244) from the USA, South Africa, and Vietnam. The gene panel consisted of FMN2, EDNRB, ZNF671, TBXT, and MOS. Cervical tissue samples from all three countries showed highly significant differential methylation in squamous cell carcinoma (SCC) with a sensitivity of 100% [95% CI 74.12–100.00], and specificity of 91% [95% CI 62.26–99.53] to 96% [95% CI 79.01–99.78], and receiver operating characteristic area under the curve (ROC AUC) = 1.000 [95% CI 1.00–1.00] compared to benign cervical tissue, and cervical intraepithelial neoplasia 2/3 with sensitivity of 55% [95% CI 37.77–70.84] to 89% [95% CI 67.20–98.03], specificity of 93% [95% CI 84.07–97.38] to 96% [95% CI 79.01–99.78], and a ROC AUC ranging from 0.793 [95% CI 0.68–0.89] to 0.99 [95% CI 0.97–1.00] compared to CIN1. In cervical smears, the marker panel detected SCC with a sensitivity of 87% [95% CI 77.45–92.69], specificity 95% [95% CI 88.64–98.18], and ROC AUC = 0.925 [95% CI 0.878–0.974] compared to normal, and high-grade squamous intraepithelial lesion (HSIL) at a sensitivity of 70% (95% CI 58.11–80.44), specificity of 94% (95% CI 88.30–97.40), and ROC AUC = 0.884 (95% CI 0.822–0.945) compared to low-grade intraepithelial lesion (LSIL)/normal in an analysis of pooled data from the three countries. Similar to HPV-positive, HPV-negative cervical carcinomas were frequently hypermethylated for these markers.

Conclusions
This 5-marker panel detected SCC and HSIL in cervical smears with a high level of sensitivity and specificity. Molecular tests with the ability to rapidly detect high-risk HSIL will lead to timely treatment for those in need and prevent unnecessary procedures in women with low-risk lesions throughout the world. Validation of these markers in prospectively collected cervical smear cells followed by the development of a hypermethylated marker-based cervical cancer detection test is warranted.