Clinical Outcomes and Risk Implications of HPV 31 Infection: A 10-Year Retrospective Cohort Study

Abstract

Objective To describe the long-term clinical outcomes of women diagnosed with human papillomavirus type 31 (HPV 31) infection and to assess its potential implications for genotype-specific cervical cancer risk stratification in a real-world screening setting.Methods This retrospective cohort study analyzed 106,450 women screened for cervical cancer at the Afyonkarahisar Cancer Early Diagnosis, Screening, and Education Center (KETEM) between 2015 and 2025. Among 3313 HPV-positive women, 147 cases with confirmed HPV 31 infection and complete follow-up data were included. Clinical outcomes, cytology results, and histopathological findings were compared across three groups: isolated HPV 31, HPV 31 co-infected with HPV 16/18, and HPV 31 co-infected with other high-risk genotypes.Results Biopsies were performed in 66 women (44.9%) due to abnormal cytology or HPV 16/18 co-infection. CIN2+ lesions were detected in 15 patients (22.7% of those biopsied; 10.2% of the entire cohort). The CIN2+ detection rate was 6.0% in isolated HPV 31 infections and 44.4% in women co-infected with HPV 16/18 (p = 0.0006). Notably, 13.9% of cytology-negative women were diagnosed with CIN2+ on histopathology. Two invasive cancers occurred in women with isolated HPV 31 infection and negative cytology at baseline.Conclusion HPV 31 infection demonstrated measurable oncogenic potential, particularly in cytology-negative women and those with HPV 16/18 co-infection. While isolated HPV 31 positivity alone may not warrant immediate colposcopy, these findings support the need for genotype-specific risk stratification in cervical cancer screening. Further multicenter and prospective studies are required to confirm these results.