Does HPV type affect outcome in oropharyngeal cancer?
- Equal contributors
1 Department of Otolaryngology, Head & Neck Surgery, The University of Western Ontario, Room B3-431A, 800 Commissioners Road East, London, N6A 5W9, , Ontario, Canada
2 London Regional Cancer Program, London, Ontario, Canada
3 Lawson Health Research Institute, London, Ontario, Canada
4 Department of Oncology, The University of Western Ontario, London, Ontario, Canada
5 Department of Pathology, The University of Western Ontario, London, Ontario, Canada
6 Department of Paediatrics, Infectious Disease Division, The University of Western Ontario, London, Ontario, Canada
7 Department of Microbiology and Immunology, The University of Western Ontario, London, Ontario, Canada
Journal of Otolaryngology - Head and Neck Surgery 2013, 42:9 doi:10.1186/1916-0216-42-9Published: 1 February 2013
An epidemic of human papillomavirus (HPV)-related oropharyngeal squamous cell cancer (OPSCC) has been reported worldwide largely due to oral infection with HPV type-16, which is responsible for approximately 90% of HPV-positive cases. The purpose of this study was to determine the rate of HPV-positive oropharyngeal cancer in Southwestern Ontario, Canada.
A retrospective search identified ninety-five patients diagnosed with OPSCC. Pre-treatment biopsy specimens were tested for p16 expression using immunohistochemistry and for HPV-16, HPV-18 and other high-risk subtypes, including 31,33,35,39,45,51,52,56,58,59,67,68, by real-time qPCR.
Fifty-nine tumours (62%) were positive for p16 expression and fifty (53%) were positive for known high-risk HPV types. Of the latter, 45 tumors (90%) were identified as HPV-16 positive, and five tumors (10%) were positive for other high-risk HPV types (HPV-18 (2), HPV-67 (2), HPV-33 (1)). HPV status by qPCR and p16 expression were extremely tightly correlated (p < 0.001, Fishers exact test). Patients with HPV-positive tumors had improved 3-year overall (OS) and disease-free survival (DFS) compared to patients with HPV-negative tumors (90% vs 65%, p = 0.001; and 85% vs 49%, p = 0.005; respectively). HPV-16 related OPSCC presented with cervical metastases more frequently than other high-risk HPV types (p = 0.005) and poorer disease-free survival was observed, although this was not statistically significant.
HPV-16 infection is responsible for a significant proportion of OPSCC in Southwestern Ontario. Other high-risk subtypes are responsible for a smaller subset of OPSCC that present less frequently with cervical metastases and may have a different prognosis.