Association of age and viral factors with high-risk HPV persistence: A retrospective follow-up study

Cervical HR-HPV persistence is the main risk factor for cervical cancer. We aimed to investigate the association of age and viral factors with HR-HPV persistence.

From 2010 to 2017, 343,128 women underwent 390,411 tests performed by the Cervista HR-HPV assay (Data C3) and 157,123 women underwent 206,505 tests performed by the GenoArray HR-HPV assay (Data G14) in nine medical centers located in central and eastern China. We combined the test results and identified 9234 HPV-specific baseline-negative records for time-to-event analyses. The study endpoint event was defined as clearance of type/group-specific HPV. Therefore, hazard ratio (HR) < 1 indicated a higher risk of HPV persistence, which is contrary to the common meaning of HR.

The median persistence time was 375 and 541.5 days for Data C3 and Data G14, respectively. For every 5-year increase in age, a 15% (95% confidence interval [CI], 11%-19%) decrease in the clearance rate was observed only after 400 days of infection. For each additional co-infected HPV, the HR was 1.80 (95% CI, 1.63-1.97) on infection initiation but decreased by 22% (95% CI, 18%-26%) every 100 days. The HR of infection recurrence was 0.48 (95% CI, 0.32-0.72). The findings were consistent across different populations and test methods and were robust in sensitivity analysis.

We found a time-dependent association of age and viral factors with HPV clearance. Older age reduced HPV clearance only after 400 days of infection. Co-infection promoted HPV clearance in the beginning, but the effect attenuated and reversed as infection persisted. Recurrent same-type infection cleared slower than the previous one.