Efficacy and safety of photodynamic therapy mediated by 5-aminolevulinic acid for the treatment of cervical intraepithelial neoplasia 2: A single-center, prospective, cohort study

Background: Photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (5-ALA) is a minimally-invasive treatment for cervical intraepithelial neoplasia (CIN). The present study was carried out to investigate the effect of 5-ALA-PDT on CIN2 and the factors influencing outcome of 5-ALA-PDT. Methods: Patients diagnosed as CIN2 who met the inclusion criteria were enrolled in this study sequentially from January 2019 to April 2020. Patients were treated by PDT or cryotherapy according to their intentions. The primary endpoint was pathological regression. The secondary endpoint was HPV clearance. Affecting factors of the efficacy of PDT and adverse events were also assessed during treatment. Results: A total of 210 patients were enrolled, including 97 patients in PDT group and 101 patients in cryotherapy group, with 12 patients excluded. There was no statistical difference in population characteristics. The pathological regression rate in PDT group was 92.0% (80/87), compared with 81.4% (79/97) in cryotherapy group (P < 0.05). The HPV clearance rate was 64.4% (56/87) in PDT group and 57.8% (56/97) in cryotherapy group (P = 0.36). The main side effects of PDT were abdominal pain (24.1%, 21/87) and increased vaginal secretions (23.0%, 20/87). On univariate analysis, the risk for lesions persisting at 6 months after PDT was increased by recurrent genital tract inflammation (P = 0.004), smoking or passive smoking (P = 0.020), and multicentric lesions (P = 0.020). Conclusion: PDT can be a safe and efficient treatment for CIN2. Risk factors for persisting HSIL after PDT include recurrent genital tract inflammation, smoking or passive smoking, and multicentric lesions.