Background: Photodynamic therapy (PDT) has been proven to be a promising therapeutic modality for selected dysplasias and malignancies in a variety of organs. We assessed the effectiveness of PDT for treating cervical intraepithelial neoplasia (CIN) by cytological and histological examinations and investigated its impact on human papillomavirus (HPV) infection.
Methods: A series of 31 patients with CIN (2 with CIN2, 29 with CIN3) were given polyhematoporphyrin ether/ester (PHE) 2 mg/kg IV. After 60 h their cervices were exposed to a 630-nm YAG-OPO laser. HPV-DNA extracted from cervical smears was amplified by the polymerase chain reaction and typed for HPV using restriction fragment length polymorphism.
Results: At 3 months after PDT, cytology and directed biopsy of the cervix revealed regression of the disease in 28 [complete remission (CR) rate 90%] of 31 patients, and HPV-DNA could be no longer detected in the cervical smears of 22 (76%) of 29 HPV-positive patients. After 12 months, all 31 patients had achieved a CR on biopsy, although HPV-DNA was still present in the cervical smears of 6 patients. The types of HPV-DNA detected 12 months after PDT were different from those seen before PDT in each of the 6 patients, suggesting that they might be reinfected with other HPV types after PDT.
Conclusion: PDT is effective not only in improving the cytological and histological measures when treating CIN but also for eradicating cervical HPV.