Evaluation of the efficacy of topical photodynamic therapy against cervical HPV infection.

Background: Persistent high-risk HPV (hr-HPV) infection is a leading cause of cervical cancer. Currently, there are no specific treatment available that can eradicate the HPV virus. Studies demonstrate that photodynamic therapy (PDT) mediated by 5-aminolevulinic acid (ALA) is highly effective for treating precancerous lesions and HPV infection of the cervix and vagina.

Aims: To evaluate the efficacy of ALA PDT for patients with hr-HPV infections but without precancerous cervical lesions.

Methods: Thirty-one patients with persistent hr-HPV infection for over one year were treated with topical ALA PDT. HPV tests, cytological examinations or colposcopy-guided biopsies were performed before and after treatment. Symptoms and adverse reactions related to PDT were also evaluated.

Results: Six-month follow-up showed that the effective rate in treating simple HPV infection was >70%. Subgroup analysis demonstrated that the presence of vaginitis, absence of significant cervical pathological changes, Type III transformation zone, and a prior history of cervical surgery were all significantly associated with persistent HPV positivity after PDT (p < 0.05). Further multivariate analysis confirmed that vaginitis and the lack of mucosal abnormalities in cervical pathology independently predicted persistent HPV positivity after PDT. In HPV-related koilocytic atypia, Ki-67 expression extended beyond the normal proliferative zone, with positive nuclei throughout the epithelium. This may indicate a mechanism for improved HPV clearance after PDT. No severe adverse events occurred during the treatment. Post-treatment evaluation revealed no structural damage or invasive alterations to the cervix.

Conclusions: ALA-PDT is a highly effective and safe non-invasive field-directed treatment option for patients with hr-HPV infection.