Objectives: In the present study (EDiTH III study), the genotype-specific prevalence of HPV in low-grade squamous intraepithelial lesions (LSIL) was estimated to predict the potential benefit of HPV vaccination in France. This prevalence was compared to that previously reported in France in high-grade cervical intraepithelial neoplasia (CIN2/3, EDiTH II study) and squamous cell carcinoma (SCC, EDiTH I study) to identify the genotypes preferentially associated with a progression to malignancy.
Methods: 397 smears with LSIL diagnosis (Preservcyt) were retrospectively collected in different centres in France and genotyped using the INNO-LiPA assay allowing the detection of 24 HPV genotypes.
Results: HPV was found in 98% of cases. The most prevalent genotypes in LSIL in France were HPV 66 (25%), HPV 16 (21%), HPV 53 (18%), 51 (17%) and 52 (14%). HPV 16 and/or 18 were present in 28% and HPV 6, 11, 16 and/or 18 in 33% of LSIL. The highest SCC/LSIL prevalence ratios were shown for HPV 16, 33 and 18.
Conclusions: With a 95% vaccine efficacy on CIN1 and theoretical vaccine coverage of 100%, HPV vaccination might prevent 27% (with a 16, 18 bivalent vaccine) and up to 32% (with a 6, 11, 16, 18 quadrivalent vaccine) of LSIL cases in France. In this study, LSIL related to HPV 16, 18 or 33 are at highest risk of progression to malignancy and thus could require a stringent surveillance. Conversely, anxiety and over-treatment could be avoided in women with low risk of progression.