The goal of this multicenter, observational study is to evaluate whether methylation testing of paired box gene 1 (PAX1) can better predict and diagnose recurrence or persistent disease in patients with positive margins after cervical conization for high-grade squamous intraepithelial lesion (HSIL). The main question it aims to answer is:

Can PAX1 gene methylation testing provide a more accurate and effective prediction and diagnosis of cervical disease recurrence/persistence in addition to existing methods? Participants will be managed according to the latest clinical guidelines, and during follow-up, a non-invasive test, PAX1 gene methylation testing, will be added.

This study is a multicenter, prospective observational study that qualitatively assesses the methylation status of the PAX1 gene in cervical exfoliated cells from patients with HSIL and positive margins after conization. The aim is to evaluate the ability of PAX1 gene methylation testing to predict treatment failure (lesion recurrence or persistence). The first follow-up occurs 6 months post-surgery, including high-risk human papillomavirus (hrHPV) testing and cytology, with referral for colposcopy, including biopsy and/or endocervical curettage (ECC), if necessary. Subsequent management and follow-up are based on examination results, following clinical guidelines, and arranged at intervals of 6-12 months depending on the findings. The follow-up includes routine clinical examinations widely applied in practice, and PAX1 testing will be completed at each follow-up visit. PAX1 testing, like hrHPV testing and cytology, will be performed using cervical exfoliated cells.

Inclusion Criteria:

• Age greater than 25 years and less than 55 years;
• First-time cervical conization (cold knife conization or loop electrosurgical excision procedure);
• Postoperative pathology showing HSIL (CIN2 or CIN3);
• Positive margins for HSIL (CIN2 or CIN3) in conization specimen.

Exclusion Criteria:

• The presence of other malignant tumors or precancerous lesions;
• Lack of willingness for follow-up;
• Pregnant or breastfeeding women;
• Unable or unwilling to complete follow-up examinations;
• History of prior cervical disease treatment (surgical or physical therapy);
• Presence of immune system disorders.

Women undergoing their first cervical conization surgery for treatment or diagnosis at seven hospitals mentioned above in Zhejiang Province.