HPV DNA/RNA detection in various oral and oropharyngeal biomaterials identifies active HPV infections also in non-neoplastic tonsils.

Previous studies describe a correlation between HPV-positivity and non-smoking in TSCC; p16INK4A-expression as surrogate-marker for HPV-DNA/RNA-positivity is discussed controversially. In the present study, these parameters are assessed prospectively. HPV-status of sputum and tonsillar-swabs was analyzed to determine their validity as surrogate-marker for tissue-HPV-status. TSCC- (n = 52) and non-neoplastic tonsillar tissue (n = 163) were analyzed. HPV-DNA- and HPV-RNA-status of total sputum, cellular fraction and supernatants, tonsillar-swabs and -tissue was determined by (RT)-PCR. Immunohistochemistry determined p16INK4A-expression. 23/163 (14.2%) non-neoplastic tonsils were HPV-DNA-positive; five patients (3 HPV16, 2 HPV11) had active HPV-infections (HPV-RNA-positive), in all biomaterials. 140/163 (85.9%) patients were either HPV-DNA-positive or HPV-DNA-negative in all samples. 21/52 (40.4%) TSCC-tonsils were HPV-DNA-positive; 17 patients were HPV-RNA-positive (14 HPV16; 4 HPV18). 40/52 (76.9%) TSCC-patients were congruent in all biomaterials. p16INK4A-expression alone would have misclassified the HPV-status of 14/52 (26.2%) TSCC-patients. This prospective study confirms the discrepancy between HPV-status and p16INK4A-expression and the significant correlation between non-smoking and HPV-DNA-positivity. HPV-sputum- and/or swab-results do not consistently match tissue-results, possibly having (detrimental) consequences if those were used to assess tissue-HPV-status. In the 5 patients with active HPV infection in the non-neoplasitic tonsils, tonsillectomy likely prevented subsequent development of TSCC.

Smoking-Induced SLPI Expression Hinders HPV Infections Also in Squamous Cell Carcinomas of the Vulva.

In HNSCC, protein- and mRNA-expression of the antileukoproteinase SLPI are significantly inverse correlated with HPV-infection suggesting that elevated expression of SLPI protects against HPV-infections. Moreover, SLPI-expression is up-regulated in HNSCC-patients reporting a smoking habit. Here, we investigate the described correlation in other HPV-driven cancers, namely vulvar squamous cell carcinoma (VSCC). FFPE samples of 99 VSCC were analyzed by PCR for HPV-DNA-expression and by RT-qPCR for SLPI-mRNA-expression. Of 99 VSCC 10 (10.1%) are HPV-positive; 9 were HPV16; 1 HPV18; all were E6/E7 mRNA-positive. 33 of the 99 patients (33.3%) reported a smoking habit; 7 (21.1%) of these were HPV-positive. Of 66 (66.7%) non-smokers 3 (4.5%) were HPV-positive. SLPI-expression was 4.0-fold lower in HPV-positive than HPV-negative patients. Smoking resulted in 2.3-fold higher SLPI expression. The data presented here indicate that SLPI plays a pivotal role in HPV-infection not only in HNSCC but also in VSCC and possibly also in other HPV-driven cancers. This however, needs to be analyzed in future studies. Furthermore these data lead to the hypothesis that the smoking induced SLPI-increase is systemic rather than local, as assumed based on the HNSCC data.