HPV16, Multigravida, and Post-CIN2 Vaccination in Chinese Patients : A Retrospective Cohort Study

Purpose: This study explores predictive factors influencing clinical outcomes in patients with cervical intraepithelial neoplasia grade 2 (CIN2) managed through simple observation. Methods: Between January 2012 and March 2021, we retrospectively analyzed data from 510 CIN2 patients managed with observation strategies at Beijing Chaoyang Hospital, Capital Medical University. Result:A total of 510 eligible patients were enrolled in this study ,with a mean age of 30.15 ± 5.82 years, and 384 (75.3%) of the cases were nulliparous. During the follow-up period (mean 37.0 ± 1.3 months), 60 (12%) opted for surgical treatment, 363 (71%) patients achieved remission time 9.1 months（range: 5.1-17.3 )months. persistent CIN2 was detected in 55 (11%), disease progression occurred in 32 (6%), and no deaths were reported, with a five-year disease progression rate (DPR) of 9.2%. Independent risk factors for disease progression included more than three pregnancies (OR 4.38, 95% CI 1.63-11.79, P=0.003), HPV16 infection (OR 4.07, 95% CI 1.88-8.81，P<0.001), and post-diagnosis HPV vaccination was an independent protective factor (OR 0.29, 95% CI 0.08-0.98, P=0.046，P=0.046). The 5-year disease progression rate (DPR) was 2.6% for patients with three or fewer HPV16-negative and vaccinated pregnancies and 72% for patients with three or more pregnancies, HPV16-positive, and unvaccinated after CIN2 diagnosis. Conclusion: Simple observation with intensive surveillance is a safe strategy for CIN2 management. Patients with HPV16 and more than three pregnancies should consider conization after childbearing, while unvaccinated patients are advised to receive HPV vaccination.