OC 12-10VALIDATION OF THE FAM19A4/MIR124-2 DNA METHYLATION TEST FOR BOTH LAVAGE- AND BRUSH-BASED SELF-SAMPLES TO DETECT CERVICAL (PRE)CANCER IN HPV-POSITIVE WOMEN

13. Molecular markers
L. De Strooper 1, V. Verhoef 1, J. Berkhof 2, A. Hesselink 3, H. De Bruin 1, F. Van Kemenade 4, R. Bosgraaf 5, R. Bekkers 5, L. Massuger 5, W. Melchers 6, R. Steenbergen 1, P. Snijders 1, C. Meijer 1, D. Heideman 1.
1Department of Pathology, VU University Medical Center, Amsterdam (Netherlands), 2Department of Epidemiology and Biostatistics, VU University Medical Center, Amsterdam (Netherlands), 3Self-Screen B.V., Amsterdam, (Netherlands), 4Department of Pathology, Erasmus MC, University Medical Center Rotterdam, Rotterdam, The Netherlands (Netherlands), 5Department of Obstetrics and Gynaecology, Radboud University Medical Center, Nijmegen, The Netherlands (Netherlands), 6Department of Medical Microbiology, Radboud University Medical Center, Nijmegen, The Netherlands (Netherlands)

Background / Objectives

DNA methylation analysis of cancer-related genes is a promising tool for HPV-positive women to identify those with cervical (pre)cancer (CIN3+) in need of treatment. However, clinical performance of methylation markers can be influenced by the sample type utilized. We describe a multiplex quantitative methylation-specific PCR that targets FAM19A4 and mir124-2 loci, to detect CIN3+ using both HPV-positive lavage- and brush self-samples.


Methods

We determined methylation thresholds for clinical classification using HPV-positive training sets comprising lavage self-samples of 182 women (including 40 with CIN3+) and brush self-samples of 224 women (including 61 with CIN3+). Subsequently, independent HPV-positive validation sets of 389 lavage self-samples (including 78 with CIN3+), and 254 brush self-samples (including 72 with CIN3+) were tested using the preset thresholds. Furthermore, the clinical performance of combined methylation analysis and HPV16/18 genotyping was determined.


Results

Training set analysis revealed similar FAM19A4 and mir124-2 thresholds for both self-sample types to yield highest CIN3+ sensitivity at 70% specificity. Validation set analysis resulted in a CIN3+ sensitivity of 70.5% (95%CI:60.4-80.6) at a specificity of 67.8% (95%CI:62.7-73.0) for lavage self-samples, and a CIN3+ sensitivity of 69.4% (95%CI:58.8-80.1) at a 76.4% (95%CI:70.2-82.6) specificity for brush self-samples. In combination with HPV16/18 genotyping, CIN3+ sensitivity and specificity were 88.5% (95%CI:81.4-95.6) and 46.0% (95%CI:40.4-51.5) for lavage self-samples, and 84.7% (95%CI:76.4-93.0) and 54.9% (95%CI:47.7-62.2) for brush self-samples.


Conclusion

FAM19A4/mir124-2 methylation analysis performs equally well in HPV-positive lavage- and brush self-samples to identify women with CIN3+. In combination with HPV16/18 genotyping, significantly higher CIN3+ sensitivities are obtained, at decreased specificity.


References