Use of Interferon-Alpha in Recurrent Respiratory Papillomatosis: 20-Year Follow-up

Objectives: The aim of this study was analysis of the results of use of interferon-α (IFN-α) in patients with recurrent respiratory papillomatosis (RRP) and correlation of the results with human papillomavirus (HPV) type. Methods: A multicenter prospective series (42 patients from 22 hospitals) yielded 20 years of follow-up of patients with RRP and HPV typing who were treated with IFN-α in doses of 3 MU/m2 3 times per week. Results: During long-term follow-up (mean ± SD, 172 ± 36.8 months), the rate of event-free survival evaluated by Kaplan-Meier analysis was 42.8%, and the overall survival rate was 82.6%. The HPV typing revealed an association of HPV 11 with a more aggressive disease course (64% of HPV 11 patients versus 24% of HPV 6 patients), a lower incidence of long-term response to IFN-α therapy (14% of HPV 11 patients versus 64% of HPV 6 patients), and a higher incidence of malignant transformation and mortality during follow-up (36% and 24%, respectively, of HPV 11 patients versus 0% of HPV 6 patients). Conclusions: The obtained results revealed maximal effectiveness of IFN-α therapy in RRP patients with HPV 6 as compared with HPV 11. The association of HPV 11 with a worse long-term response to IFN-α therapy and a higher incidence of malignant transformation and mortality is clinically important and indicates the necessity of HPV typing in RRP patients after the first biopsy.