Claudin-1 as a Biomarker of Cervical Cytology and Histology

Several immunochemistry tests are used for triaging human papilloma virus (HPV) and cytology positive cases in cervical cancer screening and as an adjunct test to diagnose cervical cancer. Claudin-1 (CLDN1) protein is a major component of the tight junction, shown to have altered expression in cervical cancer. In this study, value of CLDN1 was analysed as a screening and triage immunochemistry test compared to cytology and HPV testing. A population of 352 women attending colposcopic referral visits resulting in cervical conisation and a second population of 150 women attending routine gynaecological visits with negative cervical cytology were enrolled in a multi-centre clinical study in Hungary. Cytology and HPV (Genoid Full Spectrum HPV Amplification and Detection System) testing were carried out along with immunocytochemistry for CLDN1, and as a reference, using CINtec p16 Cytology Kit. Three different evaluation protocols were used which assessed immunostaining characteristics with or without cytological readings. High correlation observable between p16^INK4a and CLDN1 established CLDN1 as a competing marker in cervical cancer. Concordance of CLDN1 immunostaining of cervical intraepithelial neoplasia 2 and above (CIN2+) positives was 84.0 % (73.8–89.3); concordance of CIN2+ negatives was 69.0 % (59.6–75.8). In conclusion, CLDN1 has similar diagnostic potential as p16^INK4a, our results established it as a histological and cytological biomarker with the potential to improve the clinical performance of cervical cytology and histology.