Prospective cohort study of 5-aminolevulinic acid photodynamic therapy for cervical low-grade squamous intraepithelial lesions with human papillomavirus infection

Background: Some patients with cervical low-grade squamous intraepithelial lesions (LSIL) undergo invasive laser ablation or loop electrosurgical excision procedures. Photodynamic therapy (PDT) is a photosensitizer 5-aminolevulinic acid (5-ALA)-based minimally invasive technique that causes minimal normal tissue and cell damage. We investigated 5-ALA-mediated PDT efficacy for cervical LSIL complicated by human papillomavirus (HPV). Methods: This prospective cohort study was conducted on patients with cervical LSIL, who were divided into treatment (20 % 5-ALA PDT thrice every 7-14 days; n = 216) and control (observation; n = 220) groups. The treatment group underwent cervical cytology and HPV genotyping 3 months after treatment; both groups underwent cervical cytology, HPV genotyping, colposcopy biopsy, and histopathological examination 6 and 12 months post-treatment. Results: The 3-, 6-, and 12-month follow-ups revealed gradually improved cervical cytology findings: no intraepithelial lesions or malignant tumor (NILM) rates (approximately 80 %). The HPV clearance rate (baseline subtype) was approximately 68 %: approximately 60 % for HPV16/18 and 71 % for non-HPV16/18 baseline subtypes. By months 6 and 12 after PDT, the LSIL regression rate of cervical histopathology increased (75.46 %- 82.08 %). The 6- and 12-month follow-ups revealed significantly increased cervical LSIL regression rates in the treatment group. Compared with the control group, the number of HPV subtypes in the treatment group decreased significantly by 6 and 12 months. Conclusions: 5-ALA PDT effectively eliminated cervical LSIL and HPV, with sustained effects for up to 12 months post-treatment. Therefore, 5-ALA PDT is an effective and safe treatment for cervical LSIL with HPV that promotes cervical LSIL regression to normal cervical tissue.