Can human papillomavirus (HPV) genotyping classify non-16/18 high-risk HPV infection by risk stratification?

OBJECTIVE: Infection with high-risk genotypes of human papillomavirus (HR-HPV) is the major cause of invasive cervical cancers. HPV-16 and HPV-18 are known to be responsible for two-thirds of all invasive cervical carcinomas, followed by HPV-45, -31, and -33. Current guidelines only differentiate HPV-16/18 (+) by recommending direct colposcopy for treatment. We tried to evaluate whether there are differences in risk among 12 non-16/18 HR-HPV genotypes in this study. METHODS: The pathology archive database records of 1,102 consecutive gynecologic patients, who had results for cervical cytology and histology and for HPV testing, as determined by HPV 9G DNA chip, were reviewed. RESULTS: Among the 1,102 patients, 346 were non-16/18 HR-HPV (+) and 231 were HPV-16/18 (+). We calculated the odds ratios for ≥cervical intraepithelial neoplasia 2 (CIN 2) of 14 groups of each HR-HPV genotype compared with a group of HR-HPV (–) patients. Based on the odds ratio of each genotype, we divided patients with non-16/18 HR-HPV genotypes (+) into two groups: HPV-31/33/35/45/52/58 (+) and HPV-39/51/56/59/66/68 (+). The age-adjusted odds ratios for ≥CIN 2 of the HPV-31/33/35/45/52/58 (+) and HPV-39/51/56/59/66/68 (+) groups compared with a HR-HPV (–) group were 11.9 (95% CI, 7.6 to 18.8; p<0.001) and 2.4 (95% CI, 1.4 to 4.3; p<0.001), respectively, while that of the HPV-16/18 (+) group was 18.1 (95% CI, 11.6 to 28.3; p=0.003). CONCLUSION: The 12 non-16/18 HR-HPV genotypes can be further categorized (HPV-31/33/35/45/52/58 vs. HPV-39/51/56/59/66/68) by risk stratification. The HPV-31/33/35/45/52/58 genotypes might need more aggressive action. Large scale clinical trials or cohort studies are necessary to confirm our suggestion.