Evaluation of combination of ALA-PDT and interferon for cervical low-grade squamous intraepithelial lesion (LSIL)

Background: Cervical LSIL is a precancerous disease which requires regular follow-up. High risk patients need active interventions. Interferon and topical PDT have been used in the treatment of cervical LSIL. The aim of this study was to evaluate the combination use of topical PDT and interferon in the treatment of cervical LSIL. Materials and methods: A prospective study was carried out involving 159 women with cervical LSIL and high risk human papillomaviruses (hr-HPV) infection. Patients were divided into three groups. Group 1-receiving interferon suppository only, Group 2-receiving 19 mg/cm2 ALA plus post PDT interferon, and Group 3-receiving 38 mg/cm2 ALA plus post PDT interferon. The primary endpoint was pathological regression. The secondary endpoints were the HPV negative conversion rate and the adverse effects of treatment. Results: At 6-12 months after PDT, for Group 1, the effective rate, CR rate and HPV negative conversion rate was 48.3 %, 43.3 % and 24.0 %, respectively. For Group 2, the effective rate, CR rate and HPV negative conversion rate were 89.3 %, 71.4 %, and 72.4 %, respectively. For Group 3, the effective rate, CR rate and HPV negative conversion rate were 91.5 %, 66.1 %, and 64.4 %, respectively, significantly higher than those of interferon only group. Two ALA dose group study showed similar efficacy. No patient experienced serious adverse effects. Conclusions: ALA-PDT combined with interferon therapy was feasible and tolerable. Two ALA dose groups showed similar outcomes in treating cervical LSIL.