|Beitragstitel||Prevalence of transcriptionally active HPV infection in tumor-free oropharyngeal tissue of OPSCC-patients|
Although a transcriptionally active infection with high risk human papillomavirus (HR-HPV) is an established risk factor for oropharyngeal cancer (OPSCC), its natural history is still unknown. Similar to tobacco-driven carcinogenesis, a multifocal HPV infection might be responsible for “viral induced field cancerization”. The aim was to investigate the prevalence of HR-HPV in samples of normal appearing mucosa adjacent to and distant from the tumor in OPSCC patients.
49 OPSCC patients undergoing panendoscopy were prospectively enrolled. Tumor specimens and biopsies of normal appearing adjacent mucosa and of the contralateral tonsil were examined for HPV DNA by BSGP5+/6+ PCR and E6*I mRNA. p16 immunohistochemistry and histopathological examination were performed too. To avoid cross-contamination instruments were replaced after each biopsy.
Of 49 diagnostic tumor specimens 26 (53%) were positive for HR-HPV DNA and p16. 23 (47%) samples were positive for HPV RNA. Among the tumors with HPV DNA/p16 positivity, 9 (36%) samples of normal appearing adjacent mucosa were positive for HPV DNA, but only 1 (4%) for HPV RNA. In distant mucosa, 4 (17%) samples were positive for HPV DNA. In none of the distant mucosa samples, HPV RNA was detected.
Very small evidence was found for transcriptionally active HPV-infection in normal appearing adjacent and distant mucosa of OPSCC patients. HPV-DNA detection indicates that HPV infection is present but rarely biologically active in adjacent/distant tissue. The absence of HPV outside the tumor supports the observation that patients with HPV-driven OPSCC have lower risk of second primary malignancies.