Human Papillomavirus Infection in Laryngeal Tumors

Abstract

Human papillomavirus (HPV) is classified into low-risk (HPV types 6 and11) and high-risk (HPV types 16, 18, and 33) according to their oncogenic potentials. We report on the incidence of HPV infection in 33 patients with laryngeal carcinoma and 3 with laryngeal papilloma. All of these patients (34 male and 2 female; ages ranging from 27 to 81) were treated between 2007 and July 2011. HPV DNA was examined by polymerase chain reaction (PCR) using freshly frozen samples. The viral load and physical status of HPV were subsequently investigated by real-time PCR of HPV type 16 positive samples.
HPV-DNA was detected in 15.2% of patients (5 out of 33) with laryngeal cancer (4 with type 16 and one with type 33) and in 100% of patients (3 of 3) with laryngeal papilloma; all with type 6. Although all HPV type 16 positive samples showed integration, their viral load varied among cases. No significant difference was found for age, smoking, tumor stage, response to treatment, and survival rate between HPV-positive and HPV-negative patients with laryngeal cancer.
Considering the high integration rates in type 16 positive samples and the presence of samples with high viral load, high-risk HPV may be important for the etiology of laryngeal cancer as well as oropharyngeal cancer.