Promoter hypermethylation has been recently proposed as a means for head and neck squamous cell carcinoma (HNSCC) detection in salivary rinses. In a prospective study of a high-risk population, we ...showed that endothelin receptor type B (EDNRB) promoter methylation in salivary rinses is a useful biomarker for oral cancer and premalignancy.
Using that cohort, we evaluated EDNRB methylation status and 8 additional genes. Clinical risk assessment by expert clinicians was conducted and compared with biomarker performance in the prediction of premalignant and malignant disease. Methylation status of 9 genes was analyzed in salivary rinses of 191 patients by quantitative methylation-specific PCR.
HOXA9, EDNRB, and deleted in colorectal cancer (DCC) methylation were associated (P = 0.012; P < 0.0001; P = 0.0005) with premalignant or malignant disease. On multivariable modeling, histological diagnosis was only independently associated with EDNRB (P = 0.0003) or DCC (P = 0.004) methylation. A subset of patients received clinical risk classification (CRC) by expert clinicians based on lesion examination. CRC, DCC, and EDNRB were associated with diagnosis of dysplasia/cancer on univariate (P = 0.008; P = 0.026; P = 0.046) and multivariate analysis (P = 0.012; P = 0.037; P = 0.047). CRC identified dysplasia/cancer with 56% of sensitivity and 66% of specificity with a similar area under curve AUC; 0.61, 95% confidence interval (CI) = 0.60-0.81 when compared to EDNRB and DCC combined AUC (0.60, 95% CI = 0.51-0.69), sensitivity of 46% and specificity of 72%. A combination of EDNRB, DCC, and CRC was optimal AUC (0.67, 95% CI = 0.58-0.76).
EDNRB and/or DCC methylation in salivary rinses compares well to examination by an expert clinician in CRC of oral lesions. These salivary biomarkers may be particularly useful in oral premalignancy and malignancy screening in clinical care settings in which expert clinicians are not available.
Carcinogenic effect of tobacco in oral cancer is through chewing and/or smoking. Significant differences exist in development of oral cancer between tobacco users and non-users. However, molecular ...alterations induced by different forms of tobacco are yet to be fully elucidated. We developed cellular models of chronic exposure to chewing tobacco and cigarette smoke using immortalized oral keratinocytes. Chronic exposure to tobacco resulted in increased cell scattering and invasiveness in immortalized oral keratinocytes. miRNA sequencing using Illumina HiSeq 2500 resulted in the identification of 10 significantly dysregulated miRNAs (4 fold; p ≤ 0.05) in chewing tobacco treated cells and 6 in cigarette smoke exposed cells. We integrated this data with global proteomic data and identified 36 protein targets that showed inverse expression pattern in chewing tobacco treated cells and 16 protein targets that showed inverse expression in smoke exposed cells. In addition, we identified 6 novel miRNAs in chewing tobacco treated cells and 18 novel miRNAs in smoke exposed cells. Integrative analysis of dysregulated miRNAs and their targets indicates that signaling mechanisms leading to oncogenic transformation are distinct between both forms of tobacco. Our study demonstrates alterations in miRNA expression in oral cells in response to two frequently used forms of tobacco.
Background
The objective is to study the effect of Medicaid expansion on postoperative radiation therapy (PORT) delay in patients with head and neck squamous cell carcinoma (HNSCC).
Methods
Patients ...from the National Cancer Database with HNSCC undergoing curative‐intent surgery in the 2 years before and after Medicaid expansion were analyzed (n = 11 717) using the difference‐in‐differences technique to study the effect on PORT delay.
Results
The rate of PORT delay before and after expansion was 66.0% and 66.9%, respectively. Medicaid patients had more frequent PORT delay than privately insured patients (pre‐expansion 77.2% vs. 59.4%, p < 0.001; post‐expansion 76.5% vs. 60.9%, p < 0.001). Medicaid expansion had no effect on PORT delay hazard ratio 0.95, 95% confidence interval 0.81–1.12. Supplemental analyses revealed that pathologic stage, number of treating facilities, and comorbidities were among several factors associated with PORT delay in the cohort.
Conclusion
PORT delay is unacceptably frequent. Improvement in timely adjuvant therapy requires more than Medicaid expansion.
Salivary glands have essential roles in maintaining oral health, mastication, taste and speech, by secreting saliva. Salivary glands are composed of several types of cells, and each cell type is ...predicted to be involved in the carcinogenesis of different types of cancers including adenoid cystic carcinoma (ACC), acinic cell carcinoma (AciCC), salivary duct carcinoma (SDC), myoepithelial carcinoma (MECA) and other histology. In our study, we performed single nucleus RNA‐seq on three human salivary gland samples to clarify the gene expression profile of each complex cellular component of the salivary glands and related these expression patterns to expression found in salivary gland cancers (SGC) to infer cell of origin. By single nucleus RNA‐seq, salivary gland cells were stratified into four clusters: acinar cells, ductal cells 1, ductal cells 2 and myoepithelial cells/stromal cells. The localization of each cell group was verified by IHC of each cluster marker gene, and one group of ductal cells was found to represent intercalated ductal cells labeled with HES1. Furthermore, in comparison with SGC RNA‐seq data, acinar cell markers were upregulated in AciCC, but downregulated in ACC and ductal cell markers were upregulated in SDC but downregulated in MECA, suggesting that markers of origin are highly expressed in some SGC. Cell type expressions in specific SGC histology are similar to those found in normal salivary gland populations, indicating a potential etiologic relationship.
What's new?
The various cell types of the salivary glands are involved in different cancers. Relationships between salivary gland cancer and expression patterns for each cell type, however, remain largely unknown. Here, the authors investigated gene expression profiles for the different cell types using single nucleus RNA‐seq of normal human salivary gland tissues. RNA‐seq identified five cell types. Immunohistochemical labeling with HES1 further identified a novel cell cluster representing intercalated ductal cells. HES1 was significantly upregulated in salivary duct carcinoma (SDC). The findings offer insight into the cellular composition of salivary glands and suggest a possible relationship between HES1 and SDC.
Previous studies have reported conflicting information regarding the prognostic role of p16 in nonoropharyngeal head and neck squamous cell carcinoma (HNSCC).
Using the US Veterans Affairs database, ...we analyzed 1448 patients with locoregionally advanced HNSCC and known p16 status diagnosed between 2005 and 2015 and treated with surgery, radiotherapy, or chemoradiotherapy. Tumor p16 status was determined through manual review of pathology reports of primary tumor specimens. Oropharyngeal (n = 1061) or nonoropharyngeal (n = 387; hypopharyngeal, laryngeal, or oral cavity) tumor site was determined from tumor registry data and manually reviewed for accuracy. We used multivariable Cox regression to analyze the effect of p16 status on overall survival (OS), cancer-specific survival (CSS), and competing mortality (CM) for oropharyngeal or nonoropharyngeal tumor sites. All statistical tests were two-sided.
In multivariable models adjusting for treatment, stage, age, comorbidity, and body mass index, patients with p16-positive tumors had improved OS, CSS, and CM compared with patients with p16-negative tumors in both oropharyngeal (OS: hazard ratio HR = 0.53, 95% confidence interval CI = 0.40 to 0.71, P < .001; CSS: HR = 0.50, 95% CI = 0.35 to 0.73, P < .001; CM: HR = 0.59, 95% CI = 0.38 to 0.93, P = .02) and nonoropharyngeal primary sites (OS: HR = 0.41, 95% CI = 0.25 to 0.69, P < .001; CSS: HR = 0.37, 95% CI = 0.18 to 0.77, P = .008; CM: HR = 0.46, 95% CI = 0.23 to 0.95, P = .04). The prognostic impact of p16 status did not statistically significantly differ by primary tumor site for OS, CSS, or CM (Pinteraction > .05).
Our findings support the hypothesis that p16 has a similar prognostic role in both nonoropharyngeal and oropharyngeal cancer. Consideration should be given to increased testing for p16 in laryngeal, hypopharyngeal, and oral cavity primaries.
ANO1 is a calcium-activated chloride channel that is frequently overexpressed in head and neck squamous cell carcinoma (HNSCC) and other cancers. While ANO1 expression negatively correlates with ...survival in several cancers, its epigenetic regulation is poorly understood. We analyzed HNSCC samples from TCGA and a separate dataset of HPV+ oropharyngeal squamous cell carcinoma (OPSCC) samples to identify differentially methylated regions. E6 and E7 transfected normal oral keratinocytes (NOK) were used to induce hypermethylation of the ANO1 promoter. We found three CpG islands that correlated with ANO1 expression, including two positively correlated with expression. Using two HNSCC datasets with differential expression of ANO1, we showed hypermethylation of positively correlated CpG islands potentiates ANO1 expression. E7 but not E6 transfection of NOK cells led to hypermethylation of a positively correlated CpG island without a change in ANO1 expression. ANO1 promoter methylation was also correlated with patient survival. Our results are the first to show the contribution of positively correlated CpG's for regulating gene expression in HNSCC. Hypermethylation of the ANO1 promoter was strongly correlated with but not sufficient to increase ANO1 expression, suggesting methylation of positively correlated CpG's likely serves as an adjunct to other mechanisms of ANO1 activation.
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