Natural History of Adult-Onset Laryngeal Papillomatosis following Multiple Cidofovir Injections

Objectives: A prospective study was performed to assess the intermediate and long-term efficacy of intralesional cidofovir therapy associated with surgical excision in laryngeal papillomatosis in adults. Methods: Endoscopy with intralesional injection of cidofovir 5 mg/mL was performed 3 times at 4-week intervals. The concentration was later increased to 7.5 mg/mL and the interval between injections shortened to 2 weeks. Further treatment was performed at 3 or 6 months, depending on the evolution of the papillomas. After complete remission, the treatment was stopped and the patients were reviewed every 6 months. Results: Nineteen patients completed the protocol, with a mean of 4.5 injections each. Complete remission was obtained in 17 cases (89%) after a mean of 3.8 procedures. Remission was stable after a mean follow-up of 24 months (range, 8 to 57 months). With higher cidofovir concentrations at shorter intervals, patients needed fewer injections to achieve remission (mean, 2.1 versus 4.7 injections). Conclusions: The effectiveness of intralesional cidofovir therapy in adult-onset recurrent respiratory papillomatosis was impressive. Once obtained, complete remission was stable on intermediate or long-term follow-up. The concentration and the interval between injections seemed to influence the number of injections necessary to achieve remission.