Laryngeal papillomas

Classification of TP53 mutations and HPV predict survival in advanced larynx cancer

OBJECTIVES/HYPOTHESIS

Assess tumor suppressor p53 (TP53) functional mutations in the context of other biomarkers in advanced larynx cancer.

STUDY DESIGN

Prospective analysis of pretreatment tumor TP53, human papillomavirus (HPV), Bcl-xL, and cyclin D1 status in stage III and IV larynx cancer patients in a clinical trial.

METHODS

TP53 exons 4 through 9 from 58 tumors were sequenced. Mutations were grouped using three classifications based on their expected function. Each functional group was analyzed for response to induction chemotherapy, time to surgery, survival, HPV status, p16INK4a, Bcl-xl, and cyclin D1 expression.

RESULTS

TP53 mutations were found in 22 of 58 (37.9%) patients with advanced larynx cancer, including missense mutations in 13 of 58 (22.4%) patients, nonsense mutations in four of 58 (6.9%), and deletions in five of 58 (8.6%). High-risk HPV was found in 20 of 52 (38.5%) tumors. A classification based on Evolutionary Action score of p53 (EAp53) distinguished missense mutations with high risk for decreased survival from low-risk mutations (P = 0.0315). A model including this TP53 classification, HPV status, cyclin D1, and Bcl-xL staining significantly predicts survival (P = 0.0017).

CONCLUSION

EAp53 functional classification of TP53 mutants and biomarkers predict survival in advanced larynx cancer.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:E292-E299, 2016.

Consistent DNA hypermethylation patterns in laryngeal papillomas

INTRODUCTION: This study examined the contribution of promoter hypermethylation to the pathogenesis of respiratory papillomatosis (RP), including recurrences (RRP) and progression to squamous cell carcinoma (SSC). MATERIALS AND METHODS: A retrospective cohort of 25 laryngeal papilloma cases included 21 RRP, two of which progressed to SCC. Aberrant methylation status was determined using the multi-gene (22 tumor suppressor genes) methylation-specific multiplex ligation-dependent probe amplification assay and confirmed using methylation specific PCR. RESULTS: Twenty genes had altered DNA methylation in 22 of 25 cases. Aberrant methylation of CDKN2B and TIMP3 was most frequent. Promoter hypermethylation of BRCA2, APC, CDKN2A and CDKN2B was detected in 2 RRP cases with subsequent progression to SCC. Of the 25 cases, 22 were positive for HPV-6, 2 for HPV-11 and 1 for HPV-16 and 33. CONCLUSIONS: Consistent aberrant methylation of multiple tumor suppressor genes contributes to the pathogenesis of laryngeal papillomas. Persistent aberrant DNA methylation events in 2 RRP cases that progressed to cancer indicate an epigenetic monoclonal progression continuum to SCC.

Therapy for Recurrent Respiratory Papillomatosis

Human papillomaviruses types 6 or 11 are aetiological agents of recurrent respiratory papillomatosis, a disease characterized by benign exophytic tumours usually on the vocal cords. Surgery debulks the tumours, but these growths generally recur at regular intervals. Adjunct medical treatments, aimed at containing the virus and growth of tumours, include indole-3-carbinol or its dimer diindolylmethane, interferon, photodynamic therapy and others. Preventive and therapeutic vaccines hold promise for eliminating the virus.

High-risk human papillomavirus types and squamous cell carcinoma in patients with respiratory papillomas

Respiratory papillomas (RPs) are benign, virally induced tumors of the larynx and respiratory epithelium that may obstruct the airway and tend to recur frequently. RPs are thought to be the result of infection with the human papillomaviruses (HPVs) types 6 and 11. We surveyed archival RP specimens to determine whether there were correlations of HPV type with patient characteristics or clinical course. Paraffin-embedded papilloma specimens of 45 different patients were analyzed. We assessed HPV types using the polymerase chain reaction with E6 consensus primers, hybrid capture assays (high or low risk), and dot blot hybridization of generic E6 PCR products with E6 type-specific oligonucleotide probes. The presence and type of HPV were correlated with patient data from a retrospective chart review. We found that RPs may have either low- or high-risk HPV types and some contain multiple HPV types. Respiratory infection with high-risk HPV apparently introduces a long-term risk of squamous cell carcinoma development, even in the absence of conventional cofactors. Low-risk HPV infection may also act in association with these cofactors to promote carcinogenesis. Our data also show a racial imbalance in RP that may indicate a difference in genetic resistance and/or susceptibility to HPV infection and the development of RP.

Efficacy of DHE photodynamic therapy for respiratory papillomatosis: immediate and long-term results

OBJECTIVES/HYPOTHESIS

Recurrent respiratory papillomatosis is a potentially life-threatening disease that affects both children and adults and can result in complete respiratory obstruction. Conventional therapies cannot prevent multiple recurrences. The authors have been evaluating photodynamic therapy (PDT) to treat this disease since 1988. This study compared the efficacy of PDT with dihematoporphyrinether (DHE) with traditional therapy.

STUDY DESIGN

This was a randomized prospective trial of DHE-PDT. Patients were randomly assigned to receive one of two doses of DHE--3.25 mg/kg or 4.25 mg/kg body weight. They were compared with a concurrent control group. Disease extent was evaluated by direct laryngoscopy before treatment and over a 1-year period following treatment. Results were also compared with two historical cohorts of patients treated with lower doses of DHE.

METHODS

Eighty-one patients, ages 4 to 74 years, with moderate to severe recurrent disease were enrolled. Forty-eight received PDT and 33 in the control group were treated with conventional therapy. Both PDT groups received 50 J laser light to activate the drug. Patients received an intravenous infusion of DHE as outpatients 48 to 72 hours before treatment. During direct laryngoscopy, light (630 nm) was delivered by an argon-pumped dye laser. Tissue biopsies were analyzed for presence of human papillomavirus (HPV).

RESULTS

There was notable improvement with either drug dose over the first year. Those receiving 4.25 mg/kg DHE experienced a significantly larger decrease in papilloma growth rate. Three-year follow-up of a subset of patients confirmed that improvement was maintained. There was no impact of DHE-PDT on persistence of HPV DNA.

CONCLUSION

This therapy holds promise for the treatment of laryngeal papillomas.

Recurrent respiratory papillomatosis

Juvenile-onset recurrent respiratory papillomatosis is a vertically transmitted disease caused by members of the human papilloma virus family. Characterized by the relentless growth of papillomatous lesions of the larynx, recurrent respiratory papillomatosis imposes significant morbidity on patients and strain on their families. Surgical excision of the papillomata remains the mainstay of therapy, but human papilloma virus DNA persists in adjacent, normal-appearing mucosa and likely serves as a reservoir for viral reseeding. Despite multiple adjuvant treatment modalities, a cure for recurrent respiratory papillomatosis remains elusive. Most afflicted patients eventually enter spontaneous remission, but some endure several hundred surgical procedures before this welcome respite.

Antibody response to a synthetic peptide derived from the human papillomavirus type 6/11 L2 protein in recurrent respiratory papillomatosis: correlation between Southern blot hybridization, polymerase chain reaction, and serology

Recurrent respiratory papillomatosis (RRP) is the most common benign tumour of the larynx, affecting both children and adults. We present a series of 25 patients, including 10 cases of juvenile multiple, 8 cases of adult solitary, and 7 cases of adult multiple RRP. Biopsy tissue from each patient was screened by Southern blot hybridization and polymerase chain reaction for the presence of human papillomavirus (HPV) DNA. Sera from patients and age- and sex-matched controls were tested for the presence of HPV-specific antibodies using a synthetic peptide derived from the minor capsid protein (L2) of HPV 6/11. By Southern blot hybridization and/or polymerase chain reaction, biopsies from all patients were positive for HPV 6/11 DNA. There was no difference in antibody response between cases and controls. Female cases and controls had significantly higher antibody titers than male subjects. A correlation was observed between the HPV-specific antibody level and the number of surgery-necessitating recurrences.

Studies on vaccination against papillomaviruses: prophylactic and therapeutic vaccination with recombinant structural proteins

The L1 and L2 proteins of BPV-2 have been produced in Escherichia coli as beta-galactosidase fusion proteins. The fusion proteins have been used to vaccinate calves both prophylactically and therapeutically. The L1 fusion protein prevented tumor formation when administered before challenge with BPV-2, while the L2 fusion protein was very effective in promoting tumor rejection, independently from whether it was administered before or after challenge. Animals vaccinated with L1, but not with L2, responded rapidly with production of serum neutralizing antibodies, showing that this peptide contains B-cell-specific epitopes. The massive infiltration of lymphocytes in the tumors of L2-vaccinated animals suggests that the peptide contains epitopes specific for T-cells. The two structural proteins of BPV-2 therefore interact with both efferent arms of the immune system, and this observation allows the choice between two different types of antiviral vaccination.

Laryngeal papillomas: the epidemiology in a Danish subpopulation 1965-1984

The incidence rate of laryngeal papillomas in a Danish subpopulation (approximately 2.8 million inhabitants) was 3.84 x 10(-6) per year in the period 1968-1984. For juvenile papillomas the incidence rate was 3.62 x 10(-6), compared with 3.94 x 10(-6) for laryngeal papillomas of adult onset. When comparing different time periods a significantly low incidence was found in the time 1965-1968, while the incidence remained constant in 1969-1984. The low incidence rate in the early period may be real, but selectional bias may have played a part. It is general anticipated that maternal genital HPV-infections may serve as an HPV-reservoir, and that juvenile laryngeal papillomas is a result of HPV transmission from the mother to the child during birth. In the period in question cervical HPV-infections have been recorded with increasing frequency in younger women, indicating that the prevalence is rising. However, this is not reflected in the incidence of laryngeal papillomas.

Dihematoporphyrin ether-induced photosensitivity in laryngeal papilloma patients

Twenty-six patients with recurrent laryngeal papillomatosis received 2.5 mg/kg of Dihematoporphyrin Ether (DHE) intravenously prior to photodynamic therapy. All patients experienced some degree of photosensitivity, the only known side effect of DHE. Reported reactions included mild erythema and inflammation (88%), swelling (58%), blistering (23%), ocular discomfort (61.5%), pruritus (38%), and skin hyperpigmentation (46%). Length of sensitivity ranged from 4-17 weeks, with an average duration of 9 weeks. No long-term debilitating sequelae were noted. Degree of skin reaction mainly depended on how compliant the patient was in following precaution instructions. Although restrictive precautions were often difficult to strictly adhere to, most patients felt the potential benefits of the therapy far outweighed any inconvenience.

Laryngeal papillomas: clinical aspects in a series of 231 patients

The records of 231 patients with laryngeal papillomas were reviewed. Considering age at onset and sex distribution, the patients were divided into four groups: juvenile solitary, juvenile multiple, adult solitary, and adult multiple papillomas. The main conclusions are (1) it is in general impossible to predict the course in individual cases, but solitary papillomas in adults follow a less severe course than do juvenile and adult multiple cases; (2) late recurrences (up to 42 years) makes it impossible to declare a patient cured; (3) there is no linkage between puberty and the disappearance of laryngeal papillomas; (4) a latent infection, acquired at or before birth, is unlikely to be responsible for adult papillomas.

Infectious papillomavirus in the vapor of warts treated with carbon dioxide laser or electrocoagulation: detection and protection

Papillomavirus DNA has been reported recently in the vapor (smoke plume) derived from warts treated with carbon dioxide laser; this raises concerns for operator safety. We therefore have studied a group of human and bovine warts to define further the potential risk of wart therapy and to test whether a surgical mask could reduce exposure. Half of each wart was treated with carbon dioxide laser and the other half with electrocoagulation. The vapor produced by each form of therapy was collected with a dry filter vacuum apparatus and analyzed for the presence of papillomavirus. Vapor from human plantar warts was analyzed for the presence of human papillomavirus DNA, because there is no infectivity assay for human papillomavirus. Of plantar warts treated, five of eight laser-derived vapors and four of seven electrocoagulation-derived vapors were positive for human papillomavirus DNA. Greater amounts of papillomavirus DNA were usually recovered in the laser vapor than in the electrocoagulation vapor from the same wart. Bioassay readily detected infectious bovine papillomavirus in the vapor from bovine warts treated with either modality; more virus was present in laser-derived material. A surgical mask was found capable of removing virtually all laser- or electrocoagulation-derived virus, strongly suggesting that such masks can protect operators from potential inhalation exposure to papillomavirus.

Human papilloma virus (HPV) and carcinomas of the head and neck

Increasing evidence for a causal link between human papilloma virus and carcinomas of the cervix has emerged in recent research. This group of species-specific, epitheliotropic viruses has also been associated with tumours of the head and neck, but the individual reports deal only with relatively small sample numbers. In the present review these reports are considered in relation to the methods employed, and it is concluded that HPV is associated with more than 50% of oral and nasal carcinomas, as well as with carcinomas of the larynx and oesophagus. The clinical relevance and strategies for future work are outlined.