Human papillomavirus (HPV) is a critical element in the rising incidence of oropharyngeal squamous cell carcinoma (OPSCC)1-3, although whether this trend will continue, and the types of HPV responsible, are currently unknown. We previously demonstrated an increased incidence of HPV-related OPSCC in the high HPV prevalence area of Eastern Denmark from 2000-20102,3. Therefore, we investigated if the incidence for OPSCC continued to rise, the association to HPV and putative HPV types in Eastern Denmark from 2011-14. We then projected the expected incidence of OPSCC versus cervical cancer through to 2020.
Patients with OPSCC (tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BSCC)) were identified via the Danish Head and Neck Cancer Group and the Danish Pathology Databank (n=700). Tumors were re-reviewed and assessed using p16 immunohistochemistry, HPV DNA PCR, with genotyping by next generation sequencing.
Sixty-two % (432/700) of tumors were HPV-positive (HPV+). The total incidence rate (pr. 100.000) for OPSCC increased from 4.0 in 2011 to 4.5 in 2014, primarily due to a rise in HPV+ tonsillar squamous cell carcinomas (TSCCs) and HPV+ base of tongue squamous cell carcinomas (BSCCs), although numbers of HPV-negative (HPV-) OPSCC also increased during the study period. The majority of HPV+ tumors were HPV16 DNA positive (86%), but we also identified HPV33 DNA (6%), HPV35 DNA (4%), and others (3%), including HPV18, 26, 31, 45, 56, 58, 59, and HPV67.
An increasing incidence of OPSCC is driven primarily by HPV+ OPSCC. Sixty-two % of tumors were HPV+, which is a high prevalence, although the lower number of HPV- cases has yet to stabilize. HPV16 was the predominant genotype, although a significant proportion (14%) was of another genotype. Our projections suggest that the number of HPV+ OPSCC will exceed that of cervical cancer in 2016 in Eastern Denmark.
1. Simard EP, Torre L a., Jemal A. International trends in head and neck cancer incidence rates: Differences by country, sex and anatomic site. Oral Oncol 2014;50:387–403. doi:10.1016/j.oraloncology.2014.01.016.
2. Garnaes E, Kiss K, Andersen L, Therkildsen MH, Franzmann MB, Filtenborg-Barnkob B, et al. A high and increasing HPV prevalence in tonsillar cancers in Eastern Denmark, 2000-2010: The largest registry-based study to date. Int J Cancer 2014;0:1–8. doi:10.1002/ijc.29254.
3. Garnaes E, Kiss K, Andersen L, Therkildsen MH, Franzmann MB, Hoegdall E. Increasing incidence of base of tongue cancers from 2000 to 2010 due to HPV : the largest demographic study of 210 Danish patients 2015;113:131–4. doi:10.1038/bjc.2015.198.