An updated review of the epidemiological factors associated with recurrent respiratory papillomatosis

OBJECTIVES

To identify studies evaluating the epidemiology of recurrent respiratory papillomatosis (RRP), including patient demographics, human papillomavirus (HPV) immunology, clinical course, surgical and medical treatments, and psychosocial factors.

METHODS

A systematic literature search through PubMed was performed to identify studies evaluating the epidemiological factors associated with RRP. All studies were screened through a priori selection criteria using the titles and abstracts.

RESULTS

A total of 208 studies were identified, of which 54 met eligibility criteria and were included in the review.

CONCLUSIONS

RRP is a rare disease most commonly caused by HPV 6 and 11. It is characterized by recurring benign papillomatous lesions in the respiratory tract, particularly the larynx. Existing evidence about disease risk factors is limited but includes both maternal HPV infection and patient smoking and sexual behaviors. Disease management involves a combination of routine surgical and medical treatment. Surgical techniques include CO2-laser, sharp dissection, coblation, microdebridement, and photoangiolytic laser. Medical treatments which have been found to facilitate disease control off-label include interferon-alpha (IFN-α), indole-3-carbinol, acyclovir, bevacizumab, retinoids, and the Gardasil and mumps vaccines. Many patients suffer from additional psychosocial challenges related to their diagnosis. Current disease knowledge remains limited, and more robust controlled trials about risk factors, medical therapies, and surgical options are needed.

LEVEL OF EVIDENCE

5.

Evaluation of Safety of Intralesional Cidofovir for Adjuvant Treatment of Recurrent Respiratory Papillomatosis

Importance

The use of intralesional cidofovir injections for recurrent respiratory papillomatosis (RRP) remains controversial owing to concern regarding the risks of its use, including increased risk of dysplasia or carcinogenesis.

Objective

To describe the rates of dysplasia, development of malignant lesions, and adverse events associated with use of intralesional cidofovir injections as adjuvant treatment for RRP compared with patients treated without adjuvant cidofovir.

Design, Setting, and Participants

In this case series performed at a tertiary care referral center, review of electronic medical records on all adult and pediatric patients (N = 154) treated for RRP with adequate follow-up from January 1, 2000, to December 31, 2016, was performed. Data were collected on the use of cidofovir, development and presence of dysplasia or malignant lesions, complications, and intersurgical interval.

Exposures

Adjuvant intralesional cidofovir or surgical excision only.

Main Outcomes and Measures

The main outcomes measured were the development of dysplasia, malignant lesions, and complications from treatment. These outcomes were determined before collection of data.

Results

Of the 154 patients included in the analysis, 83 patients (53.9%) received adjuvant intralesional cidofovir and 71 patients (46.1%) underwent surgical excision only. One hundred patients (64.9%) were male; mean age was 27.7 (95% CI, 24.3-31.2) years. Patients were followed up for a median (interquartile range) of 70 (24-118) months in the noncidofovir group and 91 (47-152) months in the cidofovir group. There were no statistically significant differences in the rates of development of dysplasia (2.8%; 95% CI, -8.3% to 13.2%) or malignant lesions (2.2%; 95% CI, -5.3% to 11.2%) between the groups. No nephrotoxic effects were observed in the treated cohort, and only 5 minor complications that occurred in 628 injections were noted in the cidofovir group; 3 were related to direct laryngoscopy and 2 were related to needle malfunction.

Conclusions and Relevance

In this cohort of patients with RRP, adjuvant intralesional cidofovir injections did not appear to cause major complications or an increased rate of development of dysplasia and cancer.

Histologic effect of the potassium-titanyl phosphorous laser on laryngeal papilloma

Objectives

Tissue effects occurring with potassium‐titanyl phosphorous (KTP) laser treatment are difficult to quantify due to the multiple variables that affect not only the fluence (energy delivered) but also the laser–tissue interaction. This histopathologic analysis of recurrent respiratory papilloma (RRP) removed after treatment with KTP laser therapy permits correlation of histologic effect with method of laser treatment.

Methods

The histopathology of RRP resected specimens in a single patient was compared following treatment with KTP laser in contact and non‐contact modes as documented with intraoperative photography and video imaging.

Results

Epithelial‐sparing injury selective to the microvasculature was identified on histopathologic assessment of a specimen treated with noncontact angiolysis. Highly cauterized papillomatous epithelium without identifiable vascular structures was identified on tissue removed after treatment with the KTP laser in contact mode.

Conclusion

The histopathologic assessment of acute KTP laser effect on papilloma permits correlation between technique of application and tissue effect. Similar assessments may be helpful to modify dosimetry for individual patients requiring repeated treatment and may also assist in refining the development of existing KTP laser treatment classification systems.

Level of Evidence

4

Risk Factors for Dysplasia in Recurrent Respiratory Papillomatosis in an Adult and Pediatric Population

AIM

Recurrent respiratory papillomatosis (RRP) is classically described as a benign neoplasm of the larynx caused by the low-risk human papillomavirus (HPV) viral subtypes. Nevertheless, transformation to dysplasia and invasive carcinoma can occur. We aimed to assess the prevalence of dysplasia and carcinoma-ex-papilloma in both adult-onset and juvenile-onset RRP and identify patient risk factors for this dysplastic transformation.

MATERIAL AND METHODS

Ten-year retrospective chart review of a tertiary otolaryngology referral center. Patients with papilloma were identified from a review of a pathology database and clinical records. Patient demographics, pathologic data, and treatment history, including use of cidofovir as an adjunctive therapy for papilloma, were extracted from electronic medical records.

RESULTS

One hundred fifty-nine RRP patients were identified, 96 adult-onset (AORRP) and 63 juvenile-onset (JORRP) cases. Of this cohort, 139 (87%) had only benign papilloma as a pathologic diagnosis. In the AORRP cohort, 10 patients (10%) were diagnosed with dysplasia or carcinoma in situ in addition to papilloma, and 5 patients (5%) had malignant transformation to invasive carcinoma-ex-papilloma. There was a significantly higher age of disease onset for those with dysplasia or carcinoma versus those without dysplasia or carcinoma (56 vs 45 years old; P = .0005). Of the 63 JORRP patients, there were no cases of dysplasia but 3 (5%) cases of invasive carcinoma-ex-papilloma, all involving pulmonary disease. The JORRP patients with carcinoma-ex-papilloma had a younger average disease onset (2 vs 6 years old; P = .009) and a higher rate of tracheal involvement than those without carcinoma. Gender, smoking history, number of operations, or use of cidofovir showed no association with the development of dysplasia or carcinoma-ex-papillomatosis in either the AORRP or JORRP population.

CONCLUSION

In a large series of RRP, age of disease onset is the strongest predictor of dysplastic transformation in the adult and pediatric population. Carcinoma-ex-papillomatosis was uniformly associated with pulmonary disease in the JORRP population in this series. No other demographic or behavioral factors, including adjunctive therapy with cidofovir, were statistically associated with dysplasia or carcinoma-ex-papilloma.

Intralesional cidofovir as adjuvant for the successful management of aggressive respiratory papillomatosis in an infant

Recurrent respiratory papillomatosis (RRP) in young children is frequently characterized by a recalcitrant course and need for multiple surgeries. Periodic surgical debulking and ablation is the mainstay of therapy as a cure for RRP rarely occurs. Benefits of adjuvant treatment with local injection of cidofovir in aggressive cases of RRP have been reported in both children and adults. However, a consensus on initiation, dosage, or scheduling of this drug has not been established in the very young patient. Literature on successful remission in children less than 1 year of age is not available. One such case of an infant with aggressive RRP treated with local adjuvant cidofovir is described herein.

HPV associated with recurrent respiratory papillomatosis

Papillomaviruses are members of the Papillomaviridae family. Over 150 HPV types have been identified. Recurrent respiratory papillomatosis (RRP) is a chronic condition caused by HPV characterized by recurrent papillomas of the respiratory tract, mainly the larynx. During the early stages, the condition presents with hoarseness, while more advanced disease presents with stridor and respiratory distress. There is no specific cure and treatment consists of repeated surgical procedures to remove the papillomas. Most patients eventually go into remission, but some suffer for many years with this condition, which may be fatal. HPV-6 and HPV-11 are the HPV types most commonly associated with RRP. Although most studies have found RRP due to HPV-11 to be more aggressive than disease due to HPV-6, the variability in disease aggressiveness is probably multifactorial. Information regarding the current epidemiology, molecular diversity and host immune responses is important for strategizing ways to reduce disease. Data on HPV genotypes associated with RRP would provide valuable information for vaccination programs to reduce the incidence of these genotypes in mothers and, in the long term, reduce the incidence of RRP in children. This review focuses on HPV-6 and HPV-11 as the HPV types that cause RRP, and discusses the viral genome and replication, clinical presentation of RRP, current techniques of diagnosis and genotyping, and the molecular diversity of HPV-6 and HPV-11.

Systematic review of intralesional cidofovir dosing regimens in the treatment of recurrent respiratory papillomatosis

OBJECTIVE

Surgical management of recurrent respiratory papillomatosis (RRP) usually involves resection via microlaryngoscopy. Intralesional injection of cidofovir has been shown to be an effective adjuvant treatment, but remains unlicensed. United Kingdom General Medical Council guidelines recommend the prescribing doctor should "be satisfied that there is a sufficient evidence base and/or experience of using the medicine to demonstrate its safety and efficacy". This study reviews the published dosing regimens of intralesional cidofovir in the treatment of RRP in order to provide a precedent for those that wish to prescribe it.

METHODS

A systematic review of the literature was undertaken using Medline, EMBASE and CINAHL. Articles describing the use of intralesional cidofovir for RRP were reviewed. Information regarding cidofovir concentration, volume, total dose, number of treatments, interval between treatments, overall treatment period and follow up was extracted.

RESULTS

Fifty-one articles were identified. Concentration of cidofovir injected ranged from 0.0001mg/ml to 37.5mg/ml, with 5 to 7.5mg/ml being the most common. The volume of cidofovir solution injection ranged from 0.1 to 20ml. The total dose per injection ranged from 0.15 to 105mg. There was wide variation in dosing regimens with different intervals between endoscopies, number of injections and total doses delivered.

CONCLUSIONS

Based on this published literature, the precedent for prescribing intralesional cidofovir supports a concentration of 5 to 7.5mg/ml. Volumes up to 5ml per injection are routinely used. Total dose and frequency of cidofovir administration is highly variable. The need for repeat doses of cidofovir should be judged on an individual basis.

Effectiveness of cidofovir intralesional treatment in recurrent respiratory papillomatosis

To present the results of recurrent respiratory papillomatosis (RRP) treatment with surgical excision and adjuvant anti-viral cidofovir intralesional use and to examine the correlation between the cidofovir effectiveness and the patient previous history of multiple larynx procedures, age, extension of lesion and dose. 32 patients with laryngeal papillomas were treated with cidofovir in our Department between I.2009 and I.2011. The number of previous RRP debulking procedures ranged from 1 to 100. The intensity of papillomatosis differed from one anatomic site and moderate growth to four or five localizations with heavy extension. The number of injections per patient varied from 1 to 7, and the total volume of 5 mg/ml solution varied from 2 to 33 ml. The injections were combined with laser debulking of the lesions. In disperse papillomata, the injections were administered in particular anatomical sites in 4–6 weeks intervals, in massive lesions injections were repeated in the same anatomical site in 2–4 weeks. Complete remission was observed in 18 out of 32 patients. 13 patients showed remission in a place of cidofovir injection. One patient did not react to the drug. In four patients, new changes in injection places appeared. In two patients, hepatic toxic side effects were observed. Intralesional cidofovir injection has been shown to be an effective and safe therapy for laryngeal papillomatosis and should be considered in those patients who experienced disease relapse.

Natural Progression of Dysplasia in Adult Recurrent Respiratory Papillomatosis

Objectives. Recurrent respiratory papillomatosis (RRP) is often described as a benign disease. However, the natural progression of dysplasia and transformation to squamous cell carcinoma has not been elucidated for RRP. This study delineates our extensive experience with dysplasia in RRP.

Study Design/Setting. Case series with chart review.

Subjects and Methods. Demographic data and surgical pathology were analyzed for patients diagnosed with RRP at greater than 18 years of age who underwent operative intervention without cidofovir treatment for RRP between 2004 and 2009.

Results. Fifty-four patients were identified. Dysplasia was identified in 27 of 54 patients (50%). Of the 54 patients, 50% had no dysplasia, 26% had mild dysplasia (grade 1), 11% had moderate dysplasia (grade 2), 4% had severe dysplasia (grade 3), 7% had carcinoma in situ, and 2% had squamous cell carcinoma as the highest documented degree of dysplasia. Thirty of 54 patients (55.6%) had 2 or more operative interventions. Nine of the 30 patients (30%) developed a higher dysplastic grade during the course of treatment. Time to progression averaged 16.2 ± 8.7 months for patients with initially benign disease. Of those patients with dysplasia progression, only 1 of 9 (11.1%) developed squamous cell carcinoma. Patients presenting with benign or mild dysplasia typically did not progress beyond mild dysplasia (22 of 24, 91.7%).

Conclusions. Dysplasia is common in RRP. Progression of dysplasia, especially with an initial dysplastic grading of benign or mild disease, is rare.