Risk Factors for Persistent Human Papillomavirus (HPV) Infection after Conization: A Retrospective Case-Control Study Showed No Significant Association with HPV Vaccination

Introduction: Despite conization, high-grade squamous intraepithelial lesion can recur. Persistent human papilloma virus infection is an important factor of recurrence. We analyse different situations that could favor the persistence of this infection. Methods: A retrospective case-control study of 256 patients who underwent conization between 2015 and 2020 was conducted. Depending on positive or negative result of HPV test after the first 6 months post conization, two groups were defined and compared: 1) control group HPV-negative patients, 2) case group HPV-positive patients. Age, parity, smoking habit, menopause, body mass index (BMI), vaccination, HPV genotypes and exo and endocervical margin status were analysed. Results: 63 of the 256 patients studied, (24.6%) persisted positive for HPV after conization, while 193 (75.4%) became negative for HPV. Patients over 35 years old had a significantly higher risk of persistence of HPV after conization (OR 1.9). Being menopausal was also significantly associated with the persistence of HPV (OR 2.5). The presence of affected resection margins in cone specimen proved to be a risk factor for the persistence of HPV (OR 2.3). The coexistence of multiple HPV genotypes before conization seemed to be a protective factor for HPV persistence (OR 0.3). The rest of clinical characteristics studied failed to demonstrate statistical significance; therefore, it was not possible to classify them as risk and/or protective factors. Conclusions: Age over 35, menopause and affected resection margins of conization were significantly associated (p< 0.05) with the persistence of HPV infection; however, HPV vaccination was not among the risk factors.