Human papillomavirus infection as a risk factor for squamous-cell carcinoma of the head and neck
Mork J., Lie AK., Glattre E., Clark S., Hallmans G., Jellum E., Koskela P., Møller B., Pukkala E., Schiller JT., Wang Z., Youngman L., Lehtinen M., Dillner J.
Background. Oncogenic human papillomaviruses (HPVs), especially HPV type 16, cause anogenital epithelial cancers and are suspected of causing epithelial cancers of the head and neck. Material and methods. In order to examine the relation between head and neck cancers and HPVs, we performed a nested case-control study in a joint Nordic cohort in which serum samples were collected from almost 900,000 subjects. Samples collected at enrollment from 292 persons in whom squamous-cell carcinoma of the head and neck developed, on average 9.4 years after enrollment, and from 1,568 matched controls were analyzed for antibodies against HPV-16, HPV-18, HPV-33 and HPV-73 and for cotinine levels as a marker of smoking habits. Polymerase chain reaction (PCR) analysis for HPV DNA were performed in tumour tissue from 160 of the study patients with cancer. Results. After adjustment for cotinine levels, the odds ratio for squamous-cell carcinoma of the head and neck in subjects who were seropositive for HPV-16 was 2.2 (95% confidence interval, 1.4 to 3.4). No increased risk was observed for other HPV types. PCR analysis is revealed HPV-16DNA in fifty percent of oropharyngeal and 14 percent of tongue cancers. Interpretation. HPV-16 infection may be a risk factor for squamous-cell carcinoma of the head and neck.