Biological significance of genome-wide DNA methylation profiles in keloids.

OBJECTIVES/HYPOTHESIS: To obtain biological insight into keloid pathogenesis and treatment using pathway analysis of genome-wide differentially methylated gene profiles between keloid and normal skin. STUDY DESIGN: Prospective cohort. METHODS: Genome-wide profiling was previously done, with institutional review board approval, on six fresh keloid and six fresh normal skin tissue samples, using the Infinium HumanMethylation450 BeadChip kit. Statistically significant differentially methylated cytosine-phosphodiester bond-guanines (CpGs, n = 197) between keloid and normal tissue mapped to 152 genes. These genes were uploaded into Ingenuity Pathway Analysis (IPA) software to identify biological functions or regulatory networks interacting. The pathways (or "network") with an enrichment probability value ≤ .01 were subjected to a heuristic filter of keywords associated with keloid pathogenesis. RESULTS: Of the 197 CpGs, 191 were found in the IPA database and mapped to 152 unique genes. The top 10 hypermethylated genes were ACTR3C, LRRC61, PAQR4, C1orf109, SLCO2B1, CMKLR1, AHDC1, FYCO1, CCDC34, and CACNB2. The top 10 hypomethylated genes were GALNT3, SCML4, PPP1R13L, ANKRD11, WIPF1, MX2, IFFO1, DENND1C, CFH, and GHDC. IPA identified nine pathways with enrichment probability values ≤ .01, of which five (histidine degradation V1, phospholipase C signaling, colorectal cancer metastasis signaling, P2Y purinergic receptor signaling, and Gαi signaling) were associated with keloid keywords and contained "keloid genes" (P < .05). CONCLUSIONS: Genes differentially methylated between keloid and normal skin reside in known bionetwork pathways involved in critical biological functioning and signaling events in the cell. This information could be used to refine screening processes for biological significance to better understand keloid pathogenesis and to develop molecular-targeted therapy. LEVEL OF EVIDENCE: NA Laryngoscope, 127:70-78, 2017.

Investigation into the presence of human papillomavirus in patients with obstructive sleep apnea.

OBJECTIVES/HYPOTHESIS: The human papillomavirus (HPV) is known to infect the tissues of the oropharynx as demonstrated in HPV-positive oropharyngeal squamous cell carcinoma (OPSCC). HPV has also been shown to induce benign lymphoid hypertrophy. We sought to investigate an association between obstructive sleep apnea (OSA) and the presence of HPV in palatine and lingual tonsillar oropharyngeal tissue. STUDY DESIGN: Case series with chart review. METHODS: This retrospective laboratory-based study of oropharyngeal tissue from patients with OSA included patients >18 years old who underwent surgical treatment for OSA at a single institution between January 2012 and May 2014. Surgical specimens of adequate size were analyzed for HPV6, 11, and 16 using real-time quantitative polymerase chain reaction from DNA extracted from formalin-fixed paraffin-embedded tissue blocks. Student t test, Pearson χ2 test, and linear logistic regression were used to assess comparisons of body mass index (BMI), apnea-hypopnea index (AHI), age, and gender between HPV-positive and HPV-negative groups. RESULTS: Of 99 cases included in the study, six were positive for HPV: two with HPV16 and four with HPV6. BMI, AHI, age, and gender showed no significant differences between the HPV-positive and HPV-negative groups. Logistic regression to predict HPV positivity accounting for each variable and multivariate analysis were not statistically significant. CONCLUSIONS: Our study did not show HPV to have a statistically significant association with OSA. None of the covariates analyzed (BMI, AHI, gender, age) predicted HPV positivity in surgically resected oropharyngeal tissue from OSA patients. LEVEL OF EVIDENCE: 4 Laryngoscope, 127:1231-1234, 2017.

Causal network analysis of head and neck keloid tissue identifies potential master regulators.

OBJECTIVES/HYPOTHESIS: To generate novel insights and hypotheses in keloid development from potential master regulators. STUDY DESIGN: Prospective cohort. METHODS: Six fresh keloid and six normal skin samples from 12 anonymous donors were used in a prospective cohort study. Genome-wide profiling was done previously on the cohort using the Infinium HumanMethylation450 BeadChip (Illumina, San Diego, CA). The 190 statistically significant CpG islands between keloid and normal tissue mapped to 152 genes (P < .05). The top 10 statistically significant genes (VAMP5, ACTR3C, GALNT3, KCNAB2, LRRC61, SCML4, SYNGR1, TNS1, PLEKHG5, PPP1R13-α, false discovery rate <.015) were uploaded into the Ingenuity Pathway Analysis software's Causal Network Analysis (QIAGEN, Redwood City, CA). To reflect expected gene expression direction in the context of methylation changes, the inverse of the methylation ratio from keloid versus normal tissue was used for the analysis. Causal Network Analysis identified disease-specific master regulator molecules based on downstream differentially expressed keloid-specific genes and expected directionality of expression (hypermethylated vs. hypomethylated). RESULTS: Causal Network Analysis software identified four hierarchical networks that included four master regulators (pyroxamide, tributyrin, PRKG2, and PENK) and 19 intermediate regulators. CONCLUSIONS: Causal Network Analysis of differentiated methylated gene data of keloid versus normal skin demonstrated four causal networks with four master regulators. These hierarchical networks suggest potential driver roles for their downstream keloid gene targets in the pathogenesis of the keloid phenotype, likely triggered due to perturbation/injury to normal tissue. LEVEL OF EVIDENCE: NA Laryngoscope, 126:E319-E324, 2016.

The biological significance of methylome differences in human papilloma virus associated head and neck cancer.

In recent years, studies have suggested that promoter methylation in human papilloma virus (HPV) positive head and neck squamous cell carcinoma (HNSCC) has a mechanistic role and has the potential to improve patient survival. The present study aimed to replicate key molecular findings from previous analyses of the methylomes of HPV positive and HPV negative HNSCC in an independent cohort, to assess the reliability of differentially methylated markers in HPV-associated tumors. HPV was measured using real-time quantitative PCR and the biological significance of methylation differences was assessed by Ingenuity Pathway Analysis (IPA). Using an identical experimental design of a 450K methylation platform, 7 of the 11 genes were detected to be significantly differentially methylated and all 11 genes were either hypo- or hypermethylated, which was in agreement with the results of a previous study. IPA's enriched networks analysis identified one network with msh homeobox 2 (MSX2) as a central node. Locally dense interactions between genes in networks tend to reflect significant biology; therefore MSX2 was selected as an important gene. Sequestration in the top four canonical pathways was noted for 5-hydroxytryptamine receptor 1E (serotonin signaling), collapsin response mediator protein 1 (semaphorin signaling) and paired like homeodomain 2 (bone morphogenic protein and transforming growth factor-ß signaling). Placement of 9 of the 11 genes in highly ranked pathways and bionetworks identified key biological processes to further emphasize differences between HNSCC HPV positive and negative pathogenesis.

Genome-Wide Scan for Methylation Profiles in Keloids.

Keloids are benign fibroproliferative tumors of the skin which commonly occur after injury mainly in darker skinned patients. Medical treatment is fraught with high recurrence rates mainly because of an incomplete understanding of the biological mechanisms that lead to keloids. The purpose of this project was to examine keloid pathogenesis from the epigenome perspective of DNA methylation. Genome-wide profiling used the Infinium HumanMethylation450 BeadChip to interrogate DNA from 6 fresh keloid and 6 normal skin samples from 12 anonymous donors. A 3-tiered approach was used to call out genes most differentially methylated between keloid and normal. When compared to normal, of the 685 differentially methylated CpGs at Tier 3, 510 were hypomethylated and 175 were hypermethylated with 190 CpGs in promoter and 495 in nonpromoter regions. The 190 promoter region CpGs corresponded to 152 genes: 96 (63%) were hypomethylated and 56 (37%) hypermethylated. This exploratory genome-wide scan of the keloid methylome highlights a predominance of hypomethylated genomic landscapes, favoring nonpromoter regions. DNA methylation, as an additional mechanism for gene regulation in keloid pathogenesis, holds potential for novel treatments that reverse deleterious epigenetic changes. As an alternative mechanism for regulating genes, epigenetics may explain why gene mutations alone do not provide definitive mechanisms for keloid formation.

Cell signaling events differentiate ER-negative subtypes from ER-positive breast cancer.

Currently available markers routinely used in clinical practice are of limited value to patients with estrogen receptor-negative (ER(-)) breast cancer [basal-like and HER2neu-positive (HER(+))], an aggressive subtype. Our aim was to uncover molecular pathways and signaling networks exposed by differentially methylated genes informative of the biology of ER(-) breast cancer (BC) subtypes versus ER-positive (ER(+)). Whole-genome methylation array analysis was carried out using the Illumina Infinium HumanMethylation27 BeadChip on 14 primary BC: five ER(+), four triple-negative (TNBC), and five ER(-)HER2(+). Degree of methylation was calculated as a ß-value (ranging from 0 to 1), and M-values [log (ß/(1 - ß)] were used for significance tests. To identify methylated genes associated with ER(-) subtypes (TNBC and ER(-)HER2(+)) and distinct from ER(+), a weighted algorithm, developed to increase statistical rigor, called out genes in which methylation changed dramatically between ER(+) and ER(-) subtypes. Differentially methylated gene lists examined using Ingenuity Pathway Analysis called out canonical pathways and networks with clues to biological distinctiveness as well as relatedness between ER(-) subtypes as compared to ER(+) BC. The study highlights the interplay of ER(-) subtype-specific genes and their signaling pathways as potential putative fingerprints in refining classification of BC subtypes and as potential biological markers designed to hit multiple targets.

IGSF4 methylation as an independent marker of human papillomavirus-positive oropharyngeal squamous cell carcinoma.

IMPORTANCE: Human papillomavirus (HPV) is a known causative agent for oropharyngeal squamous cell carcinoma (OPSCC). Whereas it is becoming more firmly established that HPV-positive head and neck squamous cell carcinoma is associated with better survival outcomes, believed to be because of better response to chemoradiation therapy, the specific mechanisms for these improved survival outcomes remain underexplored. OBJECTIVE: To examine the relationship between HPV status and promoter methylation in an OPSCC cohort. DESIGN, SETTING, AND PARTICIPANTS: Real-time quantitative polymerase chain reaction was used to examine oncogenic HPV type 16 in a retrospective cohort of 121 patients with primary OPSCC. Aberrant promoter methylation of IGSF4, DAPK1, and ESR1 genes, known to be methylated in head and neck squamous cell carcinoma, including OPSCC, was examined by means of quantitative methylation-specific polymerase chain reaction. INTERVENTIONS: Patients received standard therapy. MAIN OUTCOMES AND MEASURES: Univariate associations between HPV and methylation were analyzed using Fisher exact tests followed by multivariable logistic regression. Cox proportional-hazards regression was used to model the risk of death given age, race, sex, HPV status, methylation, stage, smoking, and treatment. RESULTS: In univariate logistic regression analyses, HPV-positive status was significantly associated with Caucasian race (P = .02), treatment (radiotherapy only, P = .01; chemoradiotherapy, P = .007), and IGSF4 methylation (P = .005). The final multivariate logistic model, after controlling for patient characteristics (sex, age, smoking, race, and treatment) with backward variable selection among genes, retained IGSF4 methylation (OR, 4.5 [95% CI, 1.6-12.8]; P = .005), Caucasian race (OR, 2.9 [95% CI, 1.0-8.3]; P = .053), treatment (radiotherapy only vs neither: OR, 11.62 [95% CI, 2.02-66.82]; P = .02; chemoradiotherapy vs neither: OR, 11.15 [95% CI, 1.92-64.65]; P = .01), male sex (OR, 4.7 [95% CI, 1.3-17.0]; P = .02), and younger age (OR, 0.9 [95% CI, 0.90-1.0]; P = .008) as independent predictors of HPV-positive status. Cox regression modeling indicated HPV-negative status, age, male sex, smoking, and radiation treatment as independent predictors of mortality. CONCLUSIONS AND RELEVANCE: Methylation of IGSF4 is an independent predictor of HPV-positive status. DNA methylation in conjunction with HPV infection appears to play a role in OPSCC.

Methylation Markers for Early Detection and Differentiation of Follicular Thyroid Cancer Subtypes.

Thyroid cancer has the fastest rising incidence rates and is the fifth most common cancer in women. There are four main types of which the papillary and follicular types together account for >90%, followed by medullary cancers (3%-5%) and anaplastic carcinomas (<3%). For individuals who present with early stage disease of papillary and follicular cancers, there are no accurate markers to predict whether they will develop metastatic or recurrent disease. Our immediate goal is to molecularly differentiate follicular cancer subtypes for enhanced classification. Promoter methylation status of genes with reported associations in thyroid cancer (CASP8, CDKN2A, DAPK1, ESR1, NIS, RASSF1 and TIMP3) were examined in a cohort of follicular thyroid cancers comprising of 26 Hurthle and 27 Classic subtypes utilizing quantitative methylation-specific PCR. RASSF1 was differentially methylated in Classic tumor tissue compared to Hurthle (p<0.001). Methylation of RASSF1 pointed to racial group differences between African Americans and Caucasian Americans (p=0.05). Extra thyroidal extension was found to be associated with DAPK1 (p=0.014) and ESR1 (p=0.036) methylation. Late stage disease was associated with older age (p<0.001) and methylation of DAPK1 (p=0.034) and ESR1 (p=0.035). The methylation status of RASSF1, DAPK1 and ESR1 suggests the utility of methylation markers to molecularly differentiate thyroid cancer subtypes for enhanced classification and early detection of thyroid cancer.

Delineating an epigenetic continuum in head and neck cancer.

A tissue field of somatic genetic alterations precedes the histopathological phenotypic changes of carcinoma. Genomic changes could be of potential use in the diagnosis and prognosis of pre-invasive squamous head and neck carcinoma (HNSCC) lesions and as markers for cancer risk assessment. Studies of sequential molecular alterations and genetic progression of pre-invasive HNSCC have not been clearly defined. Studies have shown recurring alterations at chromosome 9p21 (location of the CDKN2A) and TP53 mutations in the early stages of HNSCC. However, gene silencing via hypermethylation is still a relatively new idea in the development of HNSCC and little is known about the contribution of epigenetics to the development of neoplasia, its transformation, progression, and recurrence in HNSCC. This review examines the role of promoter hypermethylation of tumor suppressor genes in the progression continuum from benign papillomas to malignancy in HNSCC.

Significance of p16 in Site-specific HPV Positive and HPV Negative Head and Neck Squamous Cell Carcinoma.

Expression of p16INK4A (p16 positive) is highly correlated with human papilloma virus (HPV) infection in head and neck squamous cell carcinoma (HNSCC), however, p16-positivity is not limited to HPV positive tumors and therefore, not a perfect surrogate for HPV. p16 survival outcomes are best documented for the oropharyngeal site (OP); non-OP sites such as the oral cavity (OC), larynx, and hypopharynx (HP) are understudied. The goal of this study was to evaluate p16 in the context of HPV16 and examine p16 survival outcomes in HPV16 positive and HPV16 negative site-specific HNSCC. p16 and HPV16 status were determined by immunohistochemistry and qPCR respectively, on 80 primary HNSCC from four sites: OC, OP, larynx and HP. p16 expression was different across sites (p<0.001), was more frequent in OP than non-OP sites (p<0.0001), and was different between Caucasian Americans (CA) and African Americans (AA) (p=0.031), similar to HPV (p=0.013). p16 was associated with marital status (p=0.008) and smoking (p=0.014). p16 positive patients had improved survival (similar to HPV16 positive cases). Patients with p16 negative/HPV16 negative status had the worst survival for all sites combined as well as for OP. p16 status is an important prognostic indicator in both OPSCC and non-OPSCC and the p16 positive/HPV16 negative group is likely a distinct subgroup lacking any HPV genotype. Cohorts with larger representations of non-OP sites examining multiple molecular markers will be key to deciphering and dissecting out p16's role as a useful prognostic indicator when assessed in combination with HPV status.

Epigenetic modulation of signal transduction pathways in HPV-associated HNSCC.

OBJECTIVE: Human papilloma virus (HPV) positive and HPV negative head and neck squamous cell cancer (HNSCC) are biologically distinct with a prognostic advantage for HPV positive patients compared to HPV negative cases. DNA promoter methylation is central to human diseases such as cancer, including HNSCC, with reported genome-wide hypomethylaton and promoter hypermethylation in HPV positive HNSCC tumors. The goal of this study was to identify differentially methylated genes in HPV positive versus HPV negative primary HNSCC genomes with clues to signaling networks. STUDY DESIGN: Laboratory-based study. SETTING: Primary care academic health care system. SUBJECTS AND METHODS: DNA from 4 HPV positive and 4 HPV negative freshly frozen primary HNSCC were subject to comprehensive genome-wide methylation profiling. Differentially methylated gene lists were examined using the Signal Transduction Pathways (canonical) filter in the Genomatix Pathway System (GePS). RESULTS: Twofold methylation differences were observed between HPV positive and HPV negative cases for 1168 genes. Pathway analysis applied to investigate the biological role of the 1168 differentially methylated genes revealed 8 signal transduction pathways forming a network of 66 genes, of which 62% are hypermethylated. CONCLUSION: Our study reveals a predominant hypermethylation profile for genes in signal transduction pathways of HPV positive HNSCC tumor genomes. Because signaling events in the cell play a critical role in the execution of key biological functions, insights into how complex cellular signaling cascades and networks may be programmed in HNSCC are likely to be critical in the development of new biological agents designed to hit multiple targets.

Improved survival with HPV among African Americans with oropharyngeal cancer.

PURPOSE: A major limitation of studies reporting a lower prevalence rate of human papilloma virus (HPV) in African American patients with oropharyngeal squamous cell cancer (OPSCC) than Caucasian Americans, with corresponding worse outcomes, was adequate representation of HPV-positive African American patients. This study examined survival outcomes in HPV-positive and HPV-negative African Americans with OPSCC. EXPERIMENTAL DESIGN: The study cohort of 121 patients with primary OPSCC had 42% African Americans. Variables of interest included age, race, gender, HPV status, stage, marital status, smoking, treatment, and date of diagnosis. RESULTS: Caucasian Americans are more likely to be HPV positive (OR = 3.28; P = 0.035), as are younger age (age < 50 OR = 7.14; P = 0.023 compared with age > 65) or being married (OR = 3.44; P = 0.016). HPV positivity and being unmarried were associated with being late stage (OR = 3.10; P = 0.047 and OR = 3.23; P = 0.038, respectively). HPV-negative patients had 2.7 times the risk of death as HPV-positive patients (P = 0.004). Overall, the HPV-race groups differed (log-rank P < 0.001), with significantly worse survival for HPV-negative African Americans versus (i) HPV-positive African Americans (HR = 3.44; P = 0.0012); (ii) HPV-positive Caucasian Americans (HR = 3.11; P = < 0.049); and (iii) HPV-negative Caucasian Americans (HR = 2.21; P = 0.049). CONCLUSIONS: HPV has a substantial impact on overall survival in African American patients with OPSCC. Among African American patients with OPSCC, HPV-positive patients had better survival than HPV negative. HPV-negative African Americans also did worse than both HPV-positive Caucasian Americans and HPV-negative Caucasian Americans. This study adds to the mounting evidence of HPV as a racially linked sexual behavior life style risk factor impacting survival outcomes for both African American and Caucasian American patients with OPSCC.

Human papilloma virus prevalence in a multiethnic screening population.

OBJECTIVE: The goal was to determine the prevalence of high-risk HPV16 using saliva in a screening population in Detroit, Michigan. MATERIALS AND METHODS: Real-time quantitative polymerase chain reaction was applied to detect HPV16 in saliva DNA from 349 screening subjects without head and neck cancer (HNC), 156 with HNC, and 19 controls. Cut points for human papilloma virus (HPV) positivity were >0 and >0.001 copy/cell. Proportions were compared between groups using exact χ(2) or Fisher exact tests (P < .05). RESULTS: At a cut point >0, each group had an overall HPV prevalence of more than 5%, with a higher prevalence of 30.8% in the HNC patient group. At a cut point >0.001, the prevalence was lower: 0% in the control, 1.2% in the screening, and 16.7% in the HNC group. In the latter, for both cut points, HPV prevalence was different across sites (<0.001) and significantly higher in the oropharynx than larynx or site as other after Hochberg's adjustment. At >0, women in the screening group had a higher prevalence of HPV than did men (P = .010), and at >0.001, the prevalence was higher for men in the HNC group than for women (P = .035). In the screening group, at >0, only African Americans had a higher prevalence than Caucasian Americans (P = .025). CONCLUSIONS: In the screening group, a 6.9% and 1.2% screening rate was noted at cut points >0 and >0.001, respectively. The results provide data to inform public health considerations of the feasibility of saliva as a screening tool in at-risk populations with the long-term goal of prophylactic vaccination against oral HPV.

Malignant and nonmalignant gene signatures in squamous head and neck cancer.

Genetic events specific to the pathogenesis of malignancy can offer clues to the tumorigenesis process. The objective of this study was to identify gene alterations that differentiate tumor and nontumor lesions in squamous head and neck cancer (HNSCC). DNA from 220 primary HNSCC with concurrently present tumor and nontumor lesions from the same patient was interrogated for genomic alterations of loss or gain of copy. Conditional logistic regression dealt with tumor and non-tumor records within a patient. Of 113 genes, 53 had univariate effects (P < 0.01), of which 16 genes remained in the multivariable model with P < 0.01. The model had a C-index (ROC) of 0.93. Loss of CDKN2B and gain of BCL6, FGF3, and PTP4A3 predicted tumor. Loss of BAK1 and CCND1 and gain of STCH predicted nontumor. This highly powered model assigned alterations in 16 genes specific for malignant versus nonmalignant lesions, supporting their contribution to the pathogenesis of HNSCC as well as their potential utility as relevant targets for further evaluation as markers of early detection and progression.

Disparate molecular, histopathology, and clinical factors in head and neck squamous cell carcinoma racial groups.

OBJECTIVE: There is a lack of consensus regarding the causes of the differences in the higher incidence of and the mortality from head and neck squamous cell carcinoma (HNSCC) in African Americans (AA) versus Caucasian Americans (CA). We examined a comprehensive array of risk factors influencing health and disease in an access-to-care, racially diverse, primary HNSCC cohort. STUDY DESIGN: Cross-sectional study. SETTING: Primary care academic health care system. SUBJECTS AND METHODS: The cohort of 673 patients comprised 391 CA and 282 AA (42%). Risk variables included demographic, histopathology, and clinical/epidemiologic factors. Tumor DNA was interrogated for loss and gain of 113 genes with known involvement in HNSCC/cancer. Logistic regression for univariate analysis was followed by multivariate modeling with determination of model predictability (c-index). RESULTS: Of the 39 univariate differences between AA and CA, multivariate modeling (c-index = 0.81) retained 7 differences (P < .05). AA were less likely to be married and more likely to have tumor lymphocytic response, undergo radiation treatment, and smoke. Insurance type was a significant predictor of race. AA were more likely to have Medicaid, Medicare, and other HMO types. AA tumors were more likely to have loss of CDKN2A and gain of SCYA3 versus CA. CONCLUSIONS: Multivariate modeling indicated significant differences between AA and CA HNSCC for histopathology, treatment, smoking, marital status, type of insurance, and tumor gene copy number alterations. Our data reiterate that for HNSCC, as in the case of other complex diseases, tumor genetics or biology is only one of many potential contributors to differences among racial groups.

Promoter methylation in head and neck tumorigenesis.

In addition to genetic alterations of gains and losses, epigenetic events of promoter methylation appear to further undermine a destabilized genomic repertoire in squamous head and neck carcinoma (HNSCC). This chapter provides an overview of frequently methylated tumor suppressor genes in benign head and neck papillomas, primary HNSCC tumors, and HNSCC cell lines and their relevance as epigenetic markers in head and neck tumorigenesis.

Human papillomavirus outcomes in an access-to-care laryngeal cancer cohort.

OBJECTIVE: Human papillomavirus (HPV), particularly HPV16, is a causative agent for 25% of head and neck squamous cell cancer, including laryngeal squamous cell cancer (LSCC). HPV-positive (HPV+ve) patients, particularly those with oropharyngeal SCC, have improved prognosis. For LSCC patients, this remains to be established. The goal was to determine stage and survival outcomes in LSCC in the context of HPV infection. STUDY DESIGN: Historical cohort study. SETTING: Primary care academic health system. SUBJECTS AND METHODS: In 79 patients with primary LSCC, HPV was determined using real-time quantitative polymerase chain reaction. χ(2) or Fisher exact test was used to test the association of HPV+ve with 21 risk factors including race, stage, gender, age, smoking, alcohol, treatment, and health insurance. Kaplan-Meier and log-rank tests were used to study the association of HPV and LSCC survival outcome. RESULTS: HPV16 was detected in 27% of LSCC patients. Caucasian American (CA) patients had higher HPV prevalence (33%) than did African American (AA) LSCC patients (16%; P = .058). HPV was significantly associated with gender (P = .016) and insurance type (P = .001). There were no differences in survival between HPV+ve and HPV-negative (HPV-ve) patients. There was no association with HPV and other risk factors including stage (early vs late). CONCLUSION: We found a high prevalence of HPV in men and a lower prevalence of HPV infection in AA compared with CA. Despite the strikingly better survival of patients with HPV+ve oropharyngeal tumors, even when adjusted for smoking, this correlation does not seem to hold true in the larynx. Larger multiethnic LSCC cohorts are needed to more clearly delineate HPV-related survival across ethnicities.

DNA methylation in thyroid tumorigenesis.

Thyroid cancer is the most common endocrine cancer with 1,690 deaths each year. There are four main types of which the papillary and follicular types together account for >90% followed by medullary cancers with 3% to 5% and anaplastic carcinomas making up <3%. Epigenetic events of DNA hypermethylation are emerging as promising molecular targets for cancer detection. Our immediate and long term goal is to identify DNA methylation markers for early detection of thyroid cancer. This pilot study comprised of 21 patients to include 11 papillary thyroid cancers (PTC), 2 follicular thyroid cancers (FTC), 5 normal thyroid cases, and 3 hyperthyroid cases. Aberrant promoter methylation was examined in 24 tumor suppressor genes using the methylation specific multiplex ligation-dependent probe amplification (MS-MLPA) assay and in the NIS gene using methylation-specific PCR (MSP). The frequently methylated genes were CASP8 (17/21), RASSF1 (16/21) and NIS (9/21). In the normal samples, CASP8, RASSF1 and NIS were methylated in 5/5, 4/5 and 1/5 respectively. In the hyperthyroid samples, CASP8, RASSF1 and NIS were methylated in 3/3, 2/3 and 1/3 respectively. In the thyroid cancers, CASP8, RASSF1, and NIS were methylated in 9/13, 10/13, and 7/13 respectively. CASP8, RASSF1 and NIS were also methylated in concurrently present normal thyroid tissue in 3/11, 4/11 and 3/11 matched thyroid cancer cases (matched for presence of both normal thyroid tissue and thyroid cancer), respectively. Our data suggests that aberrant methylation of CASP8, RASSF1, and NIS maybe an early change in thyroid tumorigenesis regardless of cell type.

Delineating an epigenetic continuum for initiation, transformation and progression to breast cancer.

Aberrant methylation of promoter CpG islands is a hallmark of human cancers and is an early event in carcinogenesis. We examined whether promoter hypermethylation contributes to the pathogenesis of benign breast lesions along a progression continuum to invasive breast cancer. The exploratory study cohort comprised 17 breast cancer patients with multiple benign and/or in situ lesions concurrently present with invasive carcinoma within a tumor biopsy. DNA from tumor tissue, normal breast epithelium when present, benign lesions (fibroadenoma, hyperplasia, papilloma, sclerosing adenosis, apocrine metaplasia, atypical lobular hyperplasia or atypical ductal hyperplasia), and in situ lesions of lobular carcinoma and ductal carcinoma were interrogated for promoter methylation status in 22 tumor suppressor genes using the multiplex ligation-dependent probe amplification assay (MS-MLPA). Methylation specific PCR was performed to confirm hypermethylation detected by MS-MLPA. Promoter methylation was detected in 11/22 tumor suppressor genes in 16/17 cases. Hypermethylation of RASSF1 was most frequent, present in 14/17 cases, followed by APC in 12/17, and GSTP1 in 9/17 cases with establishment of an epigenetic monocloncal progression continuum to invasive breast cancer. Hypermethylated promoter regions in normal breast epithelium, benign, and premalignant lesions within the same tumor biopsy implicate RASSF1, APC, GSTP1, TIMP3, CDKN2B, CDKN2A, ESR1, CDH13, RARB, CASP8, and TP73 as early events. DNA hypermethylation underlies thepathogenesis of step-wise transformation along a monoclonal continuum from normal to preneoplasia to invasive breast cancer.

Molecular characterization of late stomal recurrence following total laryngectomy.

The goal was to determine recurrent or second primary status for late stomal malignancies, 16 and 17 years post-total laryngectomy in two laryngeal squamous cell carcinoma (LSCC) patients, based on DNA methylation signatures and HPV typing. Adopting a literature review based definition of late stomal recurrences as new primaries at the site of the stoma or neopharynx occurring >5 years after total laryngectomy, we employed a multi-gene candidate approach to examine promoter methylation in 24 tumor suppressor genes and PCR-based assays for HPV status offered additional insights into whether the late stomal tumors post-total laryngectomy were related or not. The primary tumor for Patient 1 was negative for HPV but had aberrant hypermethylation of APC, MLH1 and BRCA1. The stomal biopsy 17-years later showed presence of HPV-16 without any methylated genes. In Patient 2, HPV-11 and promoter methylation of APC identified in the primary tumor was also observed in the stomal malignancy 16 years post-total laryngectomy. Additional information provided by molecular typing for HPV and methylation markers underscored Patient 1's and 2's late stomal presentation as most likely a second primary and recurrence, respectively. DNA methylation markers are particularly advantageous because DNA methylation is an early event in tumorigenesis, and the epigenetic modification, 5-methylcytosine, is a stable marker. Molecular marks to discern genetic heterogeneity or relatedness of stomal malignancies several years post-total laryngectomy can provide clues to their status as either second primaries or likely recurrences. Our results support the hypothesis that a subset of stomal recurrences after total laryngectomy represents second primary tumors.