Efficacy and influencing factors of CO laser, topical photodynamic therapy versus therapy combined with CO laser pretreatment for vaginal low-grade squamous intraepithelial lesions with high-risk HPV infection.

Background: Vaginal intraepithelial neoplasia (VaIN) is a group of diseases of squamous epithelial dysplasia and carcinoma in situ occurring in the vagina, which is associated with high-risk human papillomavirus (HR-HPV) infection.

Objectives: To evaluate the efficacy and safety of Carbon dioxide (CO) laser, 5-aminolevulinic acid photodynamic therapy (PDT) and PDT combined with CO laser pretreatment for VaIN1 with HR-HPV infection, and analyze the factors affecting the clearance of HR-HPV.

Methods: Patients with HR-HPV infection and pathological diagnosis of VaIN1 and received laser or PDT or PDT combined with laser pretreatment were recruited. A total of 45 patients received one to three times CO laser (laser Group), 15 patients received three times PDT (PDT Group) and 15 patients received CO laser once and PDT three times (laser + PDT Group). HPV testing, cytology and colposcopy examinations at 3-6 months and 9-12 months after treatment were analyzed to assess the outcomes of the treatment.

Results: There was no significant difference in regression rate of VaIN1 among the laser Group, the PDT Group and the laser + PDT Group (3-6 month follow-up: 57.78% vs 73.3% vs 80 %, 9-12 month follow-up: 68.89% vs 80% vs 86.67 %, P>0.05). HR-HPV remission rates were also similar in the three groups (3-6 month follow-up: 26.67% vs 46.67% vs 46.67 %, 9-12 month follow-up: 40 % in all groups, P>0.05). Compared to HR-HPV negative group, patients in the HR-HPV positive group were older and had more pregnancies. Menopause and multiple vaginal lesions were more common in the HR-HPV positive group. Adverse reactions were mild in the PDT Group. The laser Group and the laser + PDT Group had more adverse effects, such as increased vaginal secretion, vaginal bleeding, scarring and local pain.

Conclusion: For patients with VaIN1 at risk of progression, ALA-PDT presents itself as a viable choice for those who are well-informed and can consent to its costs and benefits. The addition of CO laser pretreatment may not increase the benefit of ALA-PDT treatment of VaIN1. Older age, menopause, more times of pregnancies, and multiple vaginal lesions might affect HR-HPV regression.