Background: HPV16/18 detection may improve cervical cancer risk stratification and better guide which HPV-positive women warrant immediate colposcopy/biopsy. We estimated risks of cervical precancer and cancer by HPV genotype and cytology during the implementation phase of primary HPV testing in Norway.
Methods: A total of 3111 women, aged 34-69 years, testing HPV-positive at baseline and undergoing cytology testing from February 2015 to April 2018 had data available for analysis. Risk estimates with 95% confidence intervals (95%CIs) of cervical intraepithelial neoplasia grade 3 or more severe (CIN3+) were estimated for cytology results and HPV genotypes (HPV16, HPV18, and other high-risk HPV).
Results: CIN3+ risks were higher for HPV16/18 than other high-risk HPV genotypes. Among women with any cytologic abnormality [atypical squamous cells of undetermined significance or worse], immediate risks were 57.8% (95%CI = 53.0-62.6%) for HPV16, 40.2% (95%CI = 32.3-49.2%) for HPV18, and 31.4% (95%CI = 28.7-34.3%) for other high-risk HPV. Among those with normal cytology, CIN3+ risks were 19.9% (95%CI = 15.0-26.1%) for HPV16 positives, 10.8% (95%CI = 5.6-20.5%) for HPV18 positives, and 5.5% (95%CI = 4.2-7.1%) for other high-risk HPV.
Conclusions: The benefits and harms of managing women based on HPV positivity and cytology results can be better balanced by inclusion of HPV genotyping in screening and choosing more conservative management for other high-risk HPV compared to HPV16/18.