Risk of cervical intraepithelial neoplasia grade 3 or more diagnoses for human papillomavirus16/18-positive women by cytology and co-infection status

BACKGROUND: Human papillomavirus (HPV) 16 and 18 cause approximately 70% of cervical cancer cases. The aim of this study was to evaluate whether co-infected with other HPV genotypes will affect the risk of cervical carcinogenesis in HPV16/18 positive-women. METHODS: In this cross-sectional study, cervical cytology and histological classifications from women who tested positive for HPV 16/18 and underwent colposcopy within 6 months, between January 2010 and May 2021 were obtained from West China Second University Hospital of Sichuan University. MAIN OUTCOMES AND MEASURES: Immediate risk of cervical intraepithelial neoplasia grade 3 or more diagnoses (CIN 3+). RESULTS: A total of 7940 HPV 16/18-positive women were included, with a median age of 40 years (range 25–84 years). Among them, 2710 (34.1%) were infected with multiple genotypes, 6533 (82.28%) had cytology results and 2116 (26.65%) women were diagnosed with CIN 3+. The effects of HPV 16/18 coinfecting with other HPV on CIN3 + risk varied with specific HPV genotypes. After adjusting for cofactors, compared to single HPV 16 infection, the CIN 3 + risk was significantly reduced in women infected with HPV 16 + other high-risk HPV (hrHPV) [odds ratio (OR) = 0.621, 95% confidence interval (CI) 0.511–0.755], HPV 16 + low-risk HPV (lrHPV) (OR = 0.620, 95% CI 0.436–0.883), and HPV 16 + lrHPVs + other hrHPVs (OR = 0.248, 95% CI 0.157–0.391). The prevalence of CIN 3 + was associated with increased severity of cytologic abnormalities in HPV 16/18-positive women and peaked at cytology HSIL + (89.9% and 82.3%), which held a substantially greater risk than that of NILM (OR = 65.466, 95% CI 50.234–85.316). CONCLUSIONS: In this cross-sectional study of HPV 16/18-positive women, the effects of multiple infection were likely complicated and varied with specific HPV genotypes. The coinfection of HPV 16 and other genotypes of HPV except HPV 18 was associated with decreased CIN 3 + risk. Cytologic results were informative when HPV 16/18 was positive. It might be reasonable to recommend expedited treatment for patients with HPV 16/18 positive and HSIL + cytology in the Chinese population. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13027-023-00540-9.