Effect of topical photodynamic therapy with 5-aminolevulinic acid in the treatment of high-risk cervical low-grade squamous intraepithelial lesions

This study aimed to investigate the clinical efficacy of 5-aminolevulinic acid photodynamic therapy (ALA-PDT) in the treatment of high-risk cervical low-grade squamous intraepithelial lesion (LSIL) and to analyze the influence of different risk factors on the efficacy. The clinical data of 173 patients with persistent cervical LSIL and high-risk human papillomavirus (HR-HPV) infection were retrospectively analyzed. After treatment, HPV and TCT were reexamined every 3 months, and colposcopic biopsy was performed if necessary. At 6 months of follow-up, the HPV clearance rate, complete remission (CR) rate, persistence rate, and progression rate were 73.41%, 89.60%, 8.09%, and 2.31%, respectively. The HPV clearance rate showed an upward trend with time. Moreover, the CR rates of patients with 41-50 years old group, positive HPV16/18 genotyping, and type 3 transformation zone (TZ) were 77.14%, 84.52%, and 83.33%, respectively; these rates were significantly lower compared to patients without the corresponding high-risk factors (P=0.021, 0.045, 0.042), but had no significant effect on HPV clearance rate. A subgroup analysis based on TCT results revealed no significant effect on the efficacy of ALA-PDT in the treatment of high-risk cervical LSIL. Furthermore, the 6-month CR rate and 2-year HPV clearance rate of the patients with both positive HPV16/18 genotyping and TZ3 were significantly lower than those of the patients without the two high-risk factors (73.53% vs. 94.74%, P=0.010; 78.95% vs. 97.67%, P=0.028, respectively). ALA-PDT is a safe and effective treatment for high-risk cervical LSIL. Its efficacy could be affected by patient age, HPV type, and cervical TZ type.