Abstract 2255: Diagnostic and prognostic value of oncogenic human papillomavirus in patients with carcinoma of unknown primary of the neck

Proceedings: AACR 102nd Annual Meeting 2011‐‐ Apr 2‐6, 2011; Orlando, FL Objective. To date, there is no consensus on the optimal diagnostic and therapeutic strategy for patients with carcinoma of unknown primary (CUP) of the neck. These tumors are heterogeneous in their clinical and biological characteristics, and a pre-operative prognostic marker is desirable to optimize therapy and improve outcome and survival. Human papillomavirus (HPV) is an etiologic factor in a subgroup of head and neck squamous cell carcinomas and has been identified as a significant prognostic biomarker. We sought to determine if HPV also may add relevant information on the origin and prognosis of these tumors. Material and method. 47 patients (mean age 58.7 years; 40 men, 7 women) presenting with CUP of the neck between 1994 and 2008 in Cologne were examined by standard diagnostic procedures including radiological imaging of the head, neck, thorax and abdomen, positron emission tomography (PET), panendoscopy, curettage of the nasopharynx, bilateral tonsillectomy and blind probes of the base of tongue. All patients were surgically treated with neck dissection of the diseased neck as well as adjuvant chemoradiation. The mean follow up time was 34 months. Formaldehyde-fixed, paraffin-embedded tissue specimens of the 47 metastases were examined retrospectively by means of p16INK4A immunohistochemistry, HPV-specific PCR and fluorescence in situ hybridization. Results were correlated with clinical follow-up data. Results. Oncogenic HPV was present in 12/47 (26%) metastases (10 with HPV 16), which showed also p16INK4A overexpression. In 42% of CUP patients the primary tumor was discovered during follow-up. A significant correlation between HPV positivity and later detection of the primary tumor in the oropharynx was found (p=0.038). Moreover, patients with a p16INK4A- (13/47) or HPV-positive tumor had a more favorable overall 5-year survival rate then p16INK4A- and HPV-negative tumors (69% vs 33%, p=0.05; 65% vs 37%, p=0.093; respectively). Conclusion. HPV is present in a quarter of neck metastases of CUP patients and the presence of oncogenic HPV and p16INK4A expression can serve to locate the primary tumor in the oropharynx. In addition, both biomarkers are indicators of a favorable prognosis. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 102nd Annual Meeting of the American Association for Cancer Research; 2011 Apr 2-6; Orlando, FL. Philadelphia (PA): AACR; Cancer Res 2011;71(8 Suppl):Abstract nr 2255. doi:10.1158/1538-7445.AM2011-2255