Incidence of human papillomavirus (HPV) positive tonsillar carcinoma in Stockholm, Sweden: An epidemic of viral‐induced carcinoma?

In the county of Stockholm, between 1970 and 2002, we have previously reported a 3-fold parallel increase in the incidence of tonsillar squamous cell carcinoma (SCC) and the proportion of human papillomavirus (HPV) positive tonsillar SCC. Here, we have followed the above parameters in all patients (n = 120) diagnosed with tonsillar SCC during 2003-2007 in the same area, and also in correlation to our previous data. Ninety-eight pretreatment biopsies were available and presence of HPV DNA and HPV-16 E6 and E7 RNA were tested by polymerase chain reaction (PCR) and RT-PCR. Incidence data were obtained from the Swedish Cancer Registry. Data reported from 1970 to 2002 were also obtained for comparison. HPV DNA was…