Human papillomavirus is a favourable prognostic factor in tonsillar cancer and its oncogenic role is supported by the expression of E6 and E7.

From 1970 to 2002 in the Stockholm area, we revealed a parallel three-fold increase in the incidence of tonsillar cancer and the proportion of human papillomavirus (HPV) positive tonsillar cancer cases, indicating a possible role of HPV infection in this disease. We have now examined whether HPV and viral load in pre-treatment tonsillar cancer biopsies correlates to disease prognosis, and whether the presence of HPV-16 E6 and E7 mRNA could be ascertained. The presence of HPV-16, but not viral load, in tonsillar cancer was shown to be a favourable prognostic factor for clinical outcome. Moreover, E6 and/or E7 were expressed in almost all assessable HPV-16 positive cases, supporting an oncogenic role of HPV-16 in tonsillar cancer.