Degrees of dysplasia and the use of cidofovir in patients with recurrent respiratory papillomatosis.

OBJECTIVES/HYPOTHESIS: Recurrent respiratory papillomatosis (RRP) is a benign disease characterized by recurrent lesions in the airway. The prevalence and degree of dysplasia that is present in the natural course of RRP is not well established. Adjuvant therapies, such as cidofovir, have been tried with the goal of decreasing the interval between repeat surgical treatments, the mainstay of therapy. Although, the off-label use of cidofovir to treat RRP has been common, there have been concerns regarding carcinogenic transformation following the use of cidofovir. This study aims to explore the association between increasing degree of papilloma dysplasia and the use of cidofovir in the context of the natural progression of dysplasia in RRP.

STUDY DESIGN: Retrospective case series.

METHODS: Demographic data and surgical history were obtained through chart reviews for this retrospective case series of 13 patients with RRP who had histopathologic biopsies done before and after exposure to cidofovir. Pathologic data collected over 10 years from serial excisions at the University of Iowa Hospitals were reviewed by a single pathologist, and the highest degree of dysplasia was noted per excision time.

RESULTS: Of the 176 specimens collected in these 13 patients with serial papilloma biopsies, 5.7% had no dysplasia, 57.4% had mild dysplasia (grade 1), 28.4% had moderate dysplasia (grade 2), and 8.5% had severe dysplasia (grade 3). A comparison of each patient's multiple biopsies across time suggested that the dysplastic grade was worse in two patients, better in four patients, and virtually unchanged in seven patients. There was no clear-cut pattern between the use of cidofovir and the degree of dysplasia over time.

CONCLUSIONS: These results strongly suggest that intralesional cidofovir therapy does not correlate with worsening dysplastic progression. Dysplasia is relatively common in the setting of RRP; however, the prognostic significance of this finding is unknown. Additional research is needed to delineate the natural progression of dysplasia and its clinical significance in RRP, as well as the efficacy of cidofovir.