Purpose: Patients with head and neck squamous cell carcinoma (HNSCC) who actively smoke during treatment have worse survival compared with never-smokers and former-smokers. We hypothesize the poor prognosis in tobacco smokers with HNSCC is, at least in part, due to ongoing suppression of immune response. We characterized the tumor immune microenvironment (TIM) of HNSCC in a retrospective cohort of 177 current, former, and never smokers.Experimental Design: Tumor specimens were subjected to analysis of CD3, CD8, FOXP3, PD-1, PD-L1, and pancytokeratin by multiplex immunofluorescence, whole-exome sequencing, and RNA sequencing. Immune markers were measured in tumor core, tumor margin, and stroma.Results: Our data indicate that current smokers have significantly lower numbers of CD8 þ cytotoxic T cells and PD-L1 þ cells in the TIM compared with never-and former-smokers. While tumor mutation burden and mutant allele tumor heterogeneity score do not associate with smoking status, gene-set enrichment analyses reveal significant suppression of IFNa and IFNg response pathways in current smokers. Gene expression of canonical IFN response chemokines, CXCL9, CXCL10, and CXCL11, are lower in current smokers than in former smokers, suggesting a mechanism for the decreased immune cell migration to tumor sites.Conclusions: These results suggest active tobacco use in HNSCC has an immunosuppressive effect through inhibition of tumor infiltration of cytotoxic T cells, likely as a result of suppression of IFN response pathways. Our study highlights the importance of understanding the interaction between smoking and TIM in light of emerging immune modulators for cancer management.

Oropharyngeal cancer (OPC) incidence is increasing significantly among men and often requires intensive therapy causing significant morbidity. Early detection of OPC is needed, when monotherapy can be safely delivered with less treatment‐associated morbidity, while maintaining high cure rates. We conducted a study of 101 pretreatment male OPC cases matched 1:1 to 101 disease‐free controls for age and smoking history. Oral gargles were collected from cases and controls with additional biopsies or aspirates from cases. The HPV SPF10‐LiPA25 PCR assay was utilized for HPV genotyping. Methylation of three CpG sites (438, 427 and 425) in the EPB41L3 gene and methylation status of the L1 (6,367, 6,389), L2 (4,257, 4,262, 4,266, 4,269, 4,275, 4,282) and E2 (3,412, 3,415, 3,417, 3,433, 3,436) CpG sites of HPV 16 positive specimens was assessed by pyrosequencing. Significant correlations were observed between tumor and oral specimens for all methylation biomarkers (p < 0.01). EPB41L3 and HPV 16 L1, L2 and E2 methylation were significantly (p < 0.0001) higher among cases than controls, regardless of early vs. late disease. When HPV 16 genes and EPB41L3 methylation status were combined in a logistic regression analysis, a sensitivity of 70.3% and a specificity of 90.9% were observed for the detection of OPC from an oral gargle. Our data suggest that methylation biomarkers measured in oral gargles may have utility in identifying OPC early. Future studies are needed to replicate these findings and to inform additional biomarkers that can maximize specificity and sensitivity for early OPC detection.

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IMPORTANCE The most common cause of oropharyngeal squamous cell carcinoma is human papillomavirus (HPV) infection, and currently the standard of care to determine the HPV infection status in this type of carcinoma is to use p16 immunohistochemistry as a surrogate marker of high-risk HPV infection. Although p16 immunohistochemistry is limited by the inability to determine the specific HPV genotypes, oral gargle samples may be a readily available source of HPV DNA for genotyping.OBJECTIVE To determine the specific HPV genotypes present in both oral gargle samples and tumor specimens. DESIGN, SETTING, AND PARTICIPANTSThis prospective, biomarker cohort study conducted at a single specialized cancer hospital in Florida screened approximately 800 potentially eligible participants from May 2014 through October 2017. To be eligible for participation, patients had to meet all of the following criteria: 18 years of age or older, male sex, newly diagnosed as having stage I to IV cancer of the oropharynx, a squamous cell carcinoma diagnosis, treatment naive or at least 4 weeks after chemoradiation or surgical treatment of other diseases, fully understand the study procedures and risks involved, and voluntarily agree to participate by signing an informed consent statement. MAIN OUTCOMES AND MEASURES Detection rate of HPV infection and HPV genotypes in oral gargle samples and tumor specimens.RESULTS A cohort of 204 male participants with newly diagnosed oropharyngeal squamous cell carcinoma was assessed in this prospective collection of comprehensive clinical data and oral gargle samples. Most study participants (190 [93.1%]) were white and ever smokers (114, 55.9%), with a median age of 61 years (range, 35-87 years). The HPV infection status could be assessed in 203 of 204 participants (99.5%) using oral gargle samples: 35 samples (17.2%) were negative for HPV infection, whereas 168 samples (82.8%) were positive for HPV infection. The detection rate of HPV genotypes was 93.0% in tumor specimens (160 specimens) and 82.8% (168 samples) in oral gargle samples. The oral gargle samples frequently had low-risk HPV genotypes that were not detected in tumors, but these low-risk genotypes were always a coinfection with high-risk genotypes. CONCLUSIONS AND RELEVANCEOral gargle samples can be used to detect the majority of clinically relevant HPV genotypes found in oropharyngeal squamous cell carcinoma, but the interpretation of HPV detected in these samples should be assessed with caution for general cancer risk assessment given that sensitive assays can concomitantly detect low-risk genotypes.

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