Inverse Relationship between HPV-Infection and EGFR Gene Copy Number in Head and Neck Squamous Cell Carcinomas
Sofia Hakim, Susana Moyano, Eva Bailon, Alexandra Valera, Alfons Nadal, Isam Alobid, Juan Jose Grau, Llucia Alos. Hospital Clinic, Barcelona, Spain
Background: HPV-related squamous cell carcinomas of the head and neck are more prevalent in oropharynx and sinonasal tract. The better prognosis of these tumors when comparing with HPV-negative tumors has been repeteadly reported. The EGFR gene encodes a protein that can be activated by phosphorylation, inducing a signalling transduction cascade which ultimate in cell proliferation and survival. The EGFR overexpression has been linked to a bad prognosis in several cancers, including the head and neck carcinomas.
Design: The aim of the study was to stablish the relationship between the HPV-infection and the EGFR gene status in a series of head and neck squamous cell carcinomas.
Eighty eight patients with squamous cell carcinoma of the head and neck (50 sinonasal and 38 oropharyngeal) were included in the survey. HPV was detected by PCR using SPF10 primer set (Innogenetics Diagnostica, Barcelona, Spain). EGFR gene was studied by FISH using dual-colour EGFR Spectrum-red/CEP7 Spectrum-green probe (Dako, Carpinteria, CA, USA). Immunohistochemistry for P16INK4 (Biocare Medical, Walnut Creek, CA, USA; Clone JC8; dilution 1:100) and EGFR (Dako; dilution 1:100) proteins was performed.
Results: Tumors affected 69 males and 19 females with a median age of 62 (range 25-93) years. HPV16 was detected in 18 cases (20% of tumours). The HPV- positive carcinomas affected more frequently females (53% of patients) (p<0.0004), but no significant differences in age were found. P16INK4 positivity correlated with HPV-detection in 100% of cases. High EGFR gene copy number was detected in 85% of HPV-negative carcinomas (5 amplifications and 55 polysomies); and in 39% of HPV-positive carcinomas (7 EGFR polysomies) (p<0.0001). No EGFR amplifications were detected in HPV- positive carcinomas. No correlation between EGFR gene status and EGFR protein expression was observed.
Conclusions: The molecular differences between HPV-positive and HPV-negative squamous cell carcinomas of the head and neck include the EGFR-gene status. This result may have great relevance to tailor oncological treatments in these patients.
Category: Head & Neck
Wednesday, March 21, 2012 9:30 AM
Poster Session V # 180, Wednesday Morning