Intralesional cidofovir injection for recurrent respiratory papillomatosis in Japan

The treatment of recurrent respiratory papillomatosis (RRP) continues to be difficult. Adjuvant pharmacological treatment is increasingly being used, and intralesional cidofovir injection remains the leading option. Almost all papers regarding the treatment come from the United States and Europe. The present study demonstrated it for the first time from Asia.

Ten patients with RRP were treated with intralesional cidofovir injection. The severity of papillomatosis and adverse events including blood leukocytes, blood neutrophils, and serum creatinine were evaluated before and after the completion of treatment.

Human papillomavirus (HPV) type 6 was detected in nine patients, and no types of HPV were detected in a remaining patient. Severity scores significantly improved after treatment (p=0.005). However, complete resolution was achieved in only one patient. No significant differences were observed between before and after treatment with respect to adverse events (p=0.866 for blood leukocytes, p=0.866 for blood neutrophils, and p=0.933 for serum creatinine). Squamous cell carcinoma occurred three and half years after the completion of treatment in a patient without HPV detection. However, the link between cidofovir and the occurrence of carcinoma in the case remains questionable.

This initial report of intralesional cidofovir injection for RRP from Asia demonstrated acceptable efficacy without obvious adverse events. However, the uncontrolled spread of this treatment should be avoided, and eighteen statements approved by the task force of the United States should be referred to while planning this treatment.