Changes in incidence and prevalence of human papillomavirus in tonsillar and base of tongue cancer during 2000-2016 in the Stockholm region and Sweden.

BACKGROUND: Tonsillar and base of tongue squamous cell carcinoma (TSCC/BOTSCC) has increased. In Stockholm, the proportion of human papillomavirus (HPV)-positive cases and the incidence of TSCC rose between 1970 and 2006 then stabilized. Here, HPV-prevalence, and TSCC/BOTSCC incidence 2000-2016, in Stockholm and Sweden were followed. METHODS: Incidence data for 2000-2016 were obtained from the Swedish Cancer Registry. TSCC/BOTSCC biopsies, 2013-2016 from Stockholm, were examined for HPV DNA and p16INK4a , or data obtained from medical reports. For cases 2000-2012, data were available from previous studies. RESULTS: The incidence of TSCC/BOTSCC has continued to rise in Stockholm and Sweden 2000-2016, especially after 2008. HPV DNA and p16INK4a analysis was determined for 795 Stockholm cases from 2000 to 2016, with 72% being HPV DNA and p16INK4a positive 2013-2016, and 70% positive 2000-2016. CONCLUSION: During 2000-2016, especially after 2008, the incidence of TSCC/BOTSCC has continued to increase in Stockholm and Sweden, with an HPV-prevalence of approximately 70% in Stockholm.

No evidence for human papillomavirus having a causal role in salivary gland tumors.

BACKGROUND: Salivary gland malignancies are a very heterogeneous group of cancers, with histologically > 20 different subtypes, and prognosis varies greatly. Their etiology is unknown, however, a few small studies show presence of human papillomavirus (HPV) in some subtypes, although the evidence for HPV having a causal role is weak. The aim of this study was to investigate if HPV plays a causal role in the development of different parotid salivary gland tumor subtypes. METHODS: DNA was extracted from 107 parotid salivary gland formalin fixed paraffin embedded tumors and 10 corresponding metastases, and tested for 27 different HPV types using a multiplex bead based assay. HPV DNA positive tumors were stained for p16INK4a overexpression by immunohistochemistry. RESULTS: One of the 107 malignant parotid salivary gland tumors (0.93%) and its corresponding metastasis on the neck were positive for HPV16 DNA, and both also overexpressed p16INK4a. The HPV positive primary tumor was a squamous cell carcinoma; neither mucoepidermoid nor adenoid cystic tumors were found HPV positive. CONCLUSIONS: In conclusion, HPV DNA analysis in a large number of malignant parotid salivary gland tumors, including 12 different subtypes, did not show any strong indications that tested HPV types have a causal role in the studied salivary gland tumor types.

Human papillomavirus and survival of patients per histological subsite of tonsillar squamous cell carcinoma.

Current data advocate that oropharyngeal squamous cell carcinoma (OPSCC) should be divided into subsites when evaluating the presence of human papillomavirus (HPV) and prognosis. More specifically, tonsillar squamous cell carcinoma (TSCC) and base of tongue squamous cell carcinoma (BOTSCC) have much higher HPV prevalence compared to other OPSCC. Moreover, patients with HPV positive (HPV+) TSCC and BOTSCC have a better prognosis as compared to patients with HPV negative (HPV-) corresponding tumors, while the prognostic role of HPV in other OPSCC is unclear. Furthermore, in a recent report from Denmark, TSCC was further subclassified into specified TSCC (STSCC) and nonspecified TSCC (NSTSCC), with HPV significantly more prevalent in STSCC. In this study, the histopathological influence of HPV prevalence and survival in TSCC was analyzed in a TSCC cohort with known HPV status, of patients diagnosed 1970-2002 in Stockholm. In total, 139 TSCC biopsies with both tumor and adjacent normal tissue were separated into STSCC and NSTSCC. HPV was significantly more commonly found in STSCC than in NSTSCC. Patients with HPV+ STSCC had a better disease-specific and overall survival as compared to patients with HPV+ NSTSCC, but no survival differences were observed in patients with HPV- STSCC and NSTCC. These findings confirm previous reports and suggest that TSCC subsite may also be of relevance for clinical outcome and should be further followed up in future studies.