Clinical relevance of partial HPV16/18 genotyping in stratifying HPV-positive women attending routine cervical cancer screening: a population-based cohort study

Objective: To evaluate partial HPV16/18 genotyping as a possible biomarker to select women attending HPV-based cervical cancer screening at higher risk to be referred to colposcopy. Design: Population-based cohort study. Setting: Organised cervical cancer screening programmes (Italy). Population: Women with high-risk HPV infection (period: 2015–2019). Methods: We analysed the association between partial HPV16/18 genotyping, cytology triage and histologically confirmed diagnosis of high-grade cervical intraepithelial neoplasia (CIN3⁺) lesions. Main outcome measures: Detection rate (DR) and positive predictive value (PPV) for histologically confirmed CIN3⁺ (any episode in the 2 years after baseline); sensitivity for CIN3⁺ and number of colposcopies needed for lesion detection. Results: The study included 145 437 women screened with HPV testing by the clinically validated COBAS 4800 HPV assay (Roche). Overall, 9601 (6.6%) women were HPV⁺ at baseline; HPV16 and HPV18 were present in 1865 and 594 samples, respectively. The cumulative (baseline plus 1-year repeat) cytology positivity was 42.8% and high-grade cytology was significantly higher (P < 0.0001) among women with HPV16 infection at baseline (15.2%). The cumulative CIN3⁺ DR for women with HPV16, HPV18 and other HPV-type infections was 9.8%, 3.4% and 1.8%, respectively. Conclusions: Partial HPV16 genotyping may play a role in triage, whereas HPV18 seems to behave much more similarly to the other HPV types and does not provide additional stratification. HPV16 genotyping combined with high-grade cytology can be envisaged as a triage biomarker in cervical screening to maximise CIN3⁺ detection while minimising colposcopy at baseline or 1-year repeat. Tweetable abstract: HPV16 genotyping combined with high-grade cytology can be used as triage biomarker for CIN3⁺ in HPV-positive women.