Is human papillomavirus involved in laryngeal neuroendocrine carcinoma?

The purpose of this study was to detect human papillomavirus (HPV) infection in laryngeal neuroendocrine carcinoma (LNEC) and to explore the possible relationship between HPV-induced malignant transformation and prognosis in LNEC. Ten cases of LNEC from a tertiary referral hospital were retrospectively analyzed. Clinical data were subtracted from patients' files. Pretreatment biopsy material was tested for the presence of HPV6, 11, 16, and 18 using a PCR-based detection method. Immunohistochemical staining was performed for Ki-67, p16(INK4A), and p53 expression. All cases were negative for the low-risk HPV types HPV6 and HPV11 that are associated with laryngeal papillomatosis. High-risk HPV was detected in two cases; an atypical carcinoid was positive for HPV16 and a large-cell neuroendocrine carcinoma for HPV18. Both HPV-positive tumors had a high Ki-67 labeling index. Two of the four cases with a good response to therapy were hrHPV-positive (both HPV DNA positive) compared with none of the five poor responders. Our findings show that HPV may play a role in the pathogenesis of LNEC. The relationship between HPV, improved prognosis and good response to therapy for squamous cell carcinoma of the head and neck may also be true for a subset of LNEC.