Agreement between L1 and E6/E7-based assays for detection of high-risk HPV in cervical, oropharyngeal and penile cancers.

AIMS: Human papillomavirus (HPV) molecular testing targets either the late gene L1 or early genes E6 and/or E7. Loss of L1 during integration is suggested to compromise sensitivity in samples associated with cancer, however, clear evidence for this is lacking. Our aim is to address this by performing a head-to-head comparison between assays targeting L1 vs E6/E7, using a series of high-grade and invasive disease samples within different biological matrices and anatomical sites.

METHODS: We obtained 298 samples comprising of liquid-based cytology and biopsies of cervical cancer and cervical intraepithelial neoplasia grade 3, in addition to biopsies of penile and oropharyngeal cancers. Two commercially available HPV primary screening assays and two assays with extended genotyping were applied to the sample set targeting L1 (Abbott RealTime HR HPV Assay and Optiplex HPV Genotyping Test) and E6/E7 genes (Xpert HPV Test and EuroArray HPV Test).

RESULTS: Agreement for high-risk HPV (hrHPV) for all samples types between the screening assays is over 88% and over 96% for the two genotyping assays. For HPV 16 agreement is over 90% for both screening and genotyping assays. Kappa statistics show good to very good agreement between the screening and genotyping assays for hrHPV and HPV 16.

CONCLUSIONS: Analysis of the valid results from our data indicates that L1 and E6/E7 targeting assays show similar performance for detection of hrHPV in high grade cervical lesions and cancers of cervix, penis and oropharynx.