The Molecular Biology of Mucosal Field Cancerization of the Head and Neck

Heterogeneity of 11q13 region rearrangements in laryngeal squamous cell carcinoma analyzed by microarray platforms and fluorescence in situ hybridization

We reinvestigated rearrangements occurring in region q13 of chromosome 11 aiming to: (i) describe heterogeneity of the observed structural alterations, (ii) estimate amplicon size and (iii) identify of oncogenes involved in laryngeal cancer progression as potential targets for therapy. The study included 17 cell lines derived from laryngeal cancers and 34 specimens from primary laryngeal tumors. The region 11q13 was analyzed by fluorescence in situ hybridization (FISH), array comparative genomic hybridization (aCGH) and gene expression microarray. Next, quantitative real time PCR was used for chosen genes to confirm results from aCGH and gene expression microarray. The observed pattern of aberrations allows to distinguish three ways, in which gain and amplification involving 11q13 region may occur: formation of a homogeneously staining region; breakpoints in/near 11q13, which lead to the three to sevenfold increase of the copy number of 11q13 region; the presence of additional copies of the whole chromosome 11. The minimal altered region of gain and/or amplification was limited to ~1.8 Mb (chr.11:69,395,184-71,209,568) and comprised mostly 11q13.3 band which contain 12 genes. Five, out of these genes (CCND1, ORAOV1, FADD, PPFIA1, CTTN) had higher expression levels in comparison to healthy controls. Apart from CCND1 gene, which has an established role in pathogenesis of head and neck cancers, CTTN, ORAOV1 and FADD genes appear to be oncogene-candidates in laryngeal cancers, while a function of PPFIA1 requires further studies.

Risk factors for multiple malignancies in the head and neck

OBJECTIVE

To define the prognostic role of multiple epidemiological, clinical, and biological factors for the development of multiple malignancies (MM) in patients with head and neck cancer (HNC).

STUDY DESIGN

Historical cohort study. p53 gene status, microsatellite instability (MSI) of the index tumor, and inherited chromosome fragility (CF) were studied.

SETTING

Ninety-six consecutive patients affected by primary HNC, between January 1987 and October 1991, who were eligible for curative radiation therapy were followed up.

SUBJECTS AND METHODS

p53 gene status, MSI, and CF in 96 curative radiotherapy-treated patients were correlated with the risk for MM.

RESULTS

Multiple malignancies occurred in 28.9%. Microsatellite instability (P = 0.05), CF (P < 0.01), and smoking after treatment of the index tumor (P = 0.02) were correlated with an increased risk of MM.

CONCLUSION

Genetic susceptibility may play a central role for MM development in patients with HNC.

Genetic clonal mapping of in situ and invasive ductal carcinoma indicates the field cancerization phenomenon in the breast

Nearly 80% of well-differentiated in situ duct carcinomas (g1 DCIS) have been shown to be multicentric (multilobar) lesions, while most in situ poorly differentiated duct carcinomas (g3 DCIS) were unifocal (unilobar) lesions. Here we present a clonality study of 15 cases of DCIS, all showing multiple foci. Twelve of these cases were associated with an invasive duct carcinoma. Fifteen cases of female breast cancer patients all showing multiple DCIS foci (5 g1 DCIS, 5 g2 DCIS, 5 g3 DCIS) were randomly selected and histologically studied using large histological sections. Care was taken to laser-microdissect DCIS foci that were most distantly located from one another in the same large section, and pertinent cells were genetically studied. Invasive duct carcinoma and ipsilateral lymph node metastases and/or contralateral lesions, whenever present, were additionally microdissected. DNA of neoplastic cells was purified, and the mtDNA D-loop region was sequenced. Genetic distance of different foci from the same case was visualized by phylogenetic analyses using the neighbor-joining method. Patients ranged in age from 36 to 87 years (mean 65.1). All 9 cases of widely spread DCIS were not clonal. Four of 6 cases that showed multiple adjacent foci were clonally related on mtDNA analysis. In the present series, 11/15 DCIS appeared as multiple synchronous primary breast tumors, genetically not related to one another. The present data enhance the view that breast can also show the field cancerization phenomenon, paralleling what has already been proposed in other organs.

Molecular etiology of second primary tumors in contralateral tonsils of human papillomavirus-associated index tonsillar carcinomas

OBJECTIVES

For patients with tobacco-related head and neck squamous cell carcinoma (HNSCC), the occurrence of a second primary tumor (SPT) is an ominous development that is attributed to a field cancerization effect and portends a poor clinical outcome. The goal of this study was to determine whether patients with human papillomavirus (HPV)-related index tonsillar carcinomas can also develop SPTs in the contralateral tonsil, and to discern the molecular etiology of HPV-related tumor multifocality.

MATERIALS AND METHODS

The surgical pathology archives of The Johns Hopkins Hospital were searched for all patients with primary HPV-related tonsillar squamous cell carcinoma who developed a synchronous or metachronous carcinoma in the contralateral tonsil. The HPV-16 E6 exon was sequenced from each independent cancer site to determine whether the tumor pairs harbored the same or a different HPV-16 variant.

RESULTS

Four patients with bilateral HPV-related tonsillar carcinomas were identified. In every case, the HPV DNA sequences derived from the index tumor and corresponding SPT were 100% concordant, indicating that the index and SPTs were caused by the same HPV-16 variant.

CONCLUSION

For the small subset of patients with tonsillar carcinomas who develop SPTs in the contralateral tonsil, the index case and the SPT consistently harbored the same HPV variant. This finding suggests that HPV-related tumor multi-focality can be attributed either to independent inoculation events by the same virus, or by migration of HPV-infected cells from a single inoculation site to other regions of Waldeyer's ring.

Trends over three decades of the risk of second primary cancer among patients with head and neck cancer

OBJECTIVES

Patients with a head and neck squamous cell carcinoma (HNSCC) carry a high risk of second primary cancer (SPC). In recent years, a rise in incidence of human papillomavirus (HPV)-associated HNSCC has been recorded. Moreover, tobacco and alcohol consumption levels have changed and major advances have been made in radiation treatment approaches. This raises the question of a modification to the risk of SPC, taking into account variations of patient characteristics related to the HPV-cancer epidemic.

MATERIALS AND METHODS

All patients with a first HNSCC diagnosed between 1975 and 2006 in the French Bas-Rhin region were followed up for 10 years. Multivariate Poisson regression models were used to model standardized incidence rates and excess absolute risks (EARs) over years of diagnosis, taking into account confounders such as sex, age, subsite of first HNSCC and follow-up.

RESULTS

Among these 6258 patients, 1326 presented with a SPC. High EAR values were observed for SPC of lung, head and neck, and esophagus sites (EAR of 172.8, 159.3 and 72.5 excess cancers per 10,000 person-years, respectively). Multivariate analysis showed that the excess risk of SPC of head and neck (P<.001) and esophagus (P=.029) sites decreased, with 53% lower EARs values in 2000-2006 compared to 1975-1979. In contrast, the excess risk of SPC of the lung did not change significantly (P=.174).

CONCLUSIONS

Efforts made by public health policy-makers and oncology care providers should be sustained to develop effective smoking cessation interventions, as the excess risk of lung SPC remains high and unchanged.

Oral field cancerization: current evidence and future perspectives

INTRODUCTION

Oral field cancerization implies that oral cancer does not arise as an isolated cellular phenomenon but rather as an anaplastic tendency involving many cells at once and results in the multifocal development of cancer at various rates within the entire field in response to a carcinogen especially tobacco. This concept has been frequently used to explain the occurrence of multiple primary cancers and recurrences following complete excision of oral cancer.

DISCUSSION

This review deals in detail with the origin, principle, various theories used to explain this effect and molecular, genetic, as well as cytogenetic findings related to oral field cancerization. Further, the clinical implications and future research directives are also discussed.

Second primary lung cancer after head and neck squamous cell cancer: population-based study of risk factors

BACKGROUND

Patients with head and neck squamous cell cancer (HNSCC) are at risk of developing second primary lung cancer (SPLC).

METHODS

Among 61,883 patients with HNSCC from the Surveillance, Epidemiology and End Results (SEER) database, 4522 developed SPLC (any histology) ≥2 months after HNSCC. We correlated risk with demographic and tumor-related parameters.

RESULTS

The risk of SPLC after HNSCC was 5.8%, 11.4%, and 16.4% at 5, 10, and 15 years, respectively. From Cox regression, significantly adverse (p < .0001) risk factors for SPLC included: regional versus localized HNSCC stage (hazard ratio [HR] = 1.16), hypopharyngeal or supraglottic laryngeal site (HR = 1.57), increased age (HR = 1.26/decade), black race (HR = 1.27), and male sex (HR = 1.26). Glottic (HR = 0.75) and tonsillar or oral cavity sites (HR = 0.80) were associated with significantly (p < .0001) lower risks of SPLC.

CONCLUSION

From population-based actuarial analyses, HNSCCs with more aggressive clinicopathologic features were more apt to develop SPLC, suggestive of similar environmental and/or host factors for these cancers.

Aberrant DNA methylation of tumor-related genes in oral rinse: a noninvasive method for detection of oral squamous cell carcinoma

BACKGROUND

The early detection of oral squamous cell carcinoma (OSCC) is important, and a screening test with high sensitivity and specificity is urgently needed. Therefore, in this study, the authors investigated the methylation status of tumor-related genes with the objective of establishing a noninvasive method for the detection of OSCC.

METHODS

Oral rinse samples were obtained from 34 patients with OSCC and from 24 healthy individuals (controls). The methylation status of 13 genes was determined by using methylation-specific polymerase chain reaction analysis and was quantified using a microchip electrophoresis system. Promoter methylation in each participant was screened by receiver operating characteristic analysis, and the utility of each gene's methylation status, alone and in combination with other genes, was evaluated as a tool for oral cancer detection.

RESULTS

Eight of the 13 genes had significantly higher levels of DNA methylation in samples from patients with OSCC than in controls. The genes E-cadherin (ECAD), transmembrane protein with epidermal growth factor-like and 2 follistatin-like domains 2 (TMEFF2), retinoic acid receptor beta (RARβ), and O-6 methylguanine DNA methyltransferase (MGMT) had high sensitivity (>75%) and specificity for the detection of oral cancer. OSCC was detected with 100% sensitivity and 87.5% specificity using a combination of ECAD, TMEFF2, RARβ, and MGMT and with 97.1% sensitivity and 91.7% specificity using a combination of ECAD, TMEFF2, and MGMT.

CONCLUSIONS

The aberrant methylation of a combination of marker genes present in oral rinse samples was used to detect OSCC with >90% sensitivity and specificity. The detection of methylated marker genes from oral rinse samples has great potential for the noninvasive detection of OSCC.

Effect of siRNA-mediated downregulation of VEGF in Tca8113 cells on the activity of monocyte-derived dendritic cells

Vascular endothelial growth factor (VEGF) is a tumor angiogenesis factor that is important in immune regulation. In our previous study, we found that VEGF expression in the peripheral blood and neoplasm nest from patients with oral squamous cell carcinoma (OSCC) was positively correlated with the course of disease, while an inverse correlation between VEGF expression and dendritic cells (DCs) was identified in the peripheral blood. Therefore, in the present study, we investigated whether inhibition of human VEGF in the human tongue carcinoma cell line Tca8113 had effects on the activity of monocyte-derived DCs. We knocked down the expression of human VEGF in Tca8113 cells using the small interfering RNA (siRNA) technique. Tca8113 cells pre-transfected with siRNA targeting VEGF were co-cultured with monocyte‑derived immature and mature DCs. Cell proliferation was evaluated by a WST-8 assay. Cell apoptosis, cell cycle and cell phenotypes were determined by flow cytometry. The data revealed that downregulation of the human VEGF significantly inhibited the proliferation of Tca8113 cells and increased apoptosis. Inhibition of human VEGF arrested the cell cycle of Tca8113 cells at the G0/G1 phase. Our results showed that the co-culture of DCs with Tca8113 cells markedly inhibited the expression of the mature markers of DCs including HLA-DR, CD80, CD86, CD40 and CD1a, as well as the immature marker CD83, while inhibition of human VEGF in Tca8113 cells significantly reversed these effects. Therefore, human VEGF in Tca8113 cells may not only regulate the cell proliferation and apoptosis of oral squamous cell carcinoma cells, but may also inhibit DC maturation.

Previous head and neck cancers portend poor prognoses in lung cancer patients

BACKGROUND

Although a common clinical pairing, the epidemiology and prognosis of lung cancer (LC) after head and neck cancer (HNC) is not well described.

METHODS

Data from the database of the Surveillance, Epidemiology and End Results (SEER) Program were used to study the epidemiology and survival of patients with LC after HNC. These data were compared with those from our institutional cancer registry.

RESULTS

Of all patients with a history of HNC in the SEER database, 8,225 (5%) patients went on to develop LC. This was more than three times the incidence of second primary lung cancers (1.5%). Subsequent LCs in patients with a history of HNC were more common among those with hypopharyngeal and laryngeal cancer and those with localized HNC. Patients with HNC followed by LC had poorer overall survival than did the overall population of patients with LCs in the SEER database. Overall survival after the onset of LC was dismal (median survival, 8 months). Survival was not affected by histologic concordance between HNC and LC. An analysis of 72 patients with LC after HNC reported in our institutional tumor registry over the past 37 years yielded similar results.

CONCLUSIONS

Of patients who survive LC or HNC, the latter are much more likely to develop a new pulmonary malignancy. Lung cancers that develop after HNC have a poor prognosis. This phenomenon is not explained by misclassified metastases, because histologically discordant cases behave just as poorly. Enhanced surveillance and chemoprevention strategies are needed to detect and prevent subsequent primary LC in survivors of HNC.

A gene signature in histologically normal surgical margins is predictive of oral carcinoma recurrence

Background

Oral Squamous Cell Carcinoma (OSCC) is a major cause of cancer death worldwide, which is mainly due to recurrence leading to treatment failure and patient death. Histological status of surgical margins is a currently available assessment for recurrence risk in OSCC; however histological status does not predict recurrence, even in patients with histologically negative margins. Therefore, molecular analysis of histologically normal resection margins and the corresponding OSCC may aid in identifying a gene signature predictive of recurrence.

Methods

We used a meta-analysis of 199 samples (OSCCs and normal oral tissues) from five public microarray datasets, in addition to our microarray analysis of 96 OSCCs and histologically normal margins from 24 patients, to train a gene signature for recurrence. Validation was performed by quantitative real-time PCR using 136 samples from an independent cohort of 30 patients.

Results

We identified 138 significantly over-expressed genes (> 2-fold, false discovery rate of 0.01) in OSCC. By penalized likelihood Cox regression, we identified a 4-gene signature with prognostic value for recurrence in our training set. This signature comprised the invasion-related genes MMP1, COL4A1, P4HA2, and THBS2. Over-expression of this 4-gene signature in histologically normal margins was associated with recurrence in our training cohort (p = 0.0003, logrank test) and in our independent validation cohort (p = 0.04, HR = 6.8, logrank test).

Conclusion

Gene expression alterations occur in histologically normal margins in OSCC. Over-expression of the 4-gene signature in histologically normal surgical margins was validated and highly predictive of recurrence in an independent patient cohort. Our findings may be applied to develop a molecular test, which would be clinically useful to help predict which patients are at a higher risk of local recurrence.

Cell transformation and the evolution of a field of precancerization as it relates to oral leukoplakia

Potentially malignant oral leukoplakias arise within precancerized epithelial fields consisting of cytogenetically altered keratinocytes at various stages of transformation. The evolution of a clone of keratinocytes culminating in a precancerous phenotype is a function of the number of mutagenic events, rather than the sequential order in which they occur. The altered molecular configurations of the transformed precancerous keratinocytes may confer upon them a growth advantage in relation to the unaltered neighbouring keratinocytes. Replicative clonal expansion of these keratinocytes results in the progressive replacement of the surrounding normal keratinocytes by the fitter clone or clones of altered cells. The precancerized oral epithelial field may have a clinically normal appearance and microscopically may be normal or may show dysplasia. Oral leukoplakias arising within a precancerized epithelial field in which the keratinocytes show DNA aneuploidy or loss of heterozygosity at certain specific chromosomal loci have the potential to progress to carcinoma. The pathogenic mechanisms that drive the carcinomatous transformation of oral leukoplakias, in which cytogenetic alterations in the keratinocytes cannot be detected, are unknown.

Role of DNA methylation in head and neck cancer

Head and neck cancer (HNC) is a heterogenous and complex entity including diverse anatomical sites and a variety of tumor types displaying unique characteristics and different etilogies. Both environmental and genetic factors play a role in the development of the disease, but the underlying mechanism is still far from clear. Previous studies suggest that alterations in the genes acting in cellular signal pathways may contribute to head and neck carcinogenesis. In cancer, DNA methylation patterns display specific aberrations even in the early and precancerous stages and may confer susceptibility to further genetic or epigenetic changes. Silencing of the genes by hypermethylation or induction of oncogenes by promoter hypomethylation are frequent mechanisms in different types of cancer and achieve increasing diagnostic and therapeutic importance since the changes are reversible. Therefore, methylation analysis may provide promising clinical applications, including the development of new biomarkers and prediction of the therapeutic response or prognosis. In this review, we aimed to analyze the available information indicating a role for the epigenetic changes in HNC.

Anatomic sites at elevated risk of second primary cancer after an index head and neck cancer

BACKGROUND

Patients with head and neck squamous cell carcinoma (HNSCC) are at significantly elevated risk of second primary malignancies (SPM), most commonly within the head and neck, lung, and esophagus (HNLE). Our objectives were to quantify the excess risk of SPM across all anatomic sites in which SPM risk is meaningfully elevated, including non-HNLE sites, in a large cohort of US patients.

METHODS

Population-based analysis of 75,087 patients with HNSCC in the SEER program, quantifying excess SPM risk by integrating relative (standardized incidence ratio; SIR) and absolute (excess absolute risk per 10,000 person-years at risk; EAR) statistics.

RESULTS

In HNSCC patients, the SIR of a second primary solid cancer was 2.2 (95% CI 2.1-2.2), corresponding to EAR of 167.7 additional cases per 10,000 person-years at risk. Over 1 year, 60 patients would need to be followed to observe one excess SPM. Lung cancer burden was most markedly elevated in absolute terms (EAR = 75.2), followed by HN (EAR = 59.8), esophageal (EAR = 14.2), and colorectal (EAR = 4.3) cancers. Lesser but significant excess risks were also observed for cancers of the bladder, liver, stomach, pancreas, kidney, salivary glands, nasopharynx, uterine cervix, and lymphoma.

CONCLUSIONS

Data from a large population-based US cohort reveals that HNSCC patients experience markedly excess risk of SPM, predominantly in the HNLE sites. Furthermore, the risk of SPM is also meaningfully elevated, although to a lesser degree, in multiple other tobacco-associated sites.

Loss of heterozygosity at 9p and p53 immunopositivity in surgical margins predict local relapse in head and neck squamous cell carcinoma

A major problem in head and neck cancer surgery is the high rate of local relapse (LR). In at least 25% of the surgically treated head and neck squamous cell carcinoma (HNSCC) patients, a genetically defined preneoplastic lesion, also known as "field," can be detected in the surgical margins. A remaining field may be an important cause for the development of LR. The aims of our study are (i) to investigate whether HNSCC patients with an unresected field are more likely to develop LR, and (ii) to identify molecular risk factors that predict malignant transformation of field. We retrospectively studied 35 HNSCC patients of whom 16 patients developed LR and 19 patients remained disease-free for at least 4 years. Loss of heterozygosity (LOH) at chromosomes 3p, 9p and 17p, p53 immunostaining, Ki-67 immunostaining and histopathological grading of all available paraffin-embedded surgical margins was performed, and related to LR. Significant associations were determined by Kaplan-Meier analysis and Cox-proportional hazard models. We show that presence of field is significantly associated with LR and that LOH at 9p and p53 immunostaining have the most predictive potential (hazard ratios 3.17 and 3.46, and p values 0.027 and 0.017, respectively). The combination of LOH at 9p and/or a large p53 positive field is most predictive (hazard ratio 7.06 and p = 0.01). Presence and grade of dysplasia was not associated with LR. These data may have major impact for future diagnostic workup of surgically treated HNSCC patients.

Second primary cancers after an index head and neck cancer: subsite-specific trends in the era of human papillomavirus-associated oropharyngeal cancer

PURPOSE

Patients with head and neck squamous cell carcinoma (HNSCC) are at elevated risk of second primary malignancies (SPM), most commonly of the head and neck (HN), lung, and esophagus. Our objectives were to identify HNSCC subsite-specific differences in SPM risk and distribution and to describe trends in risk over 3 decades, before and during the era of human papillomavirus (HPV) -associated oropharyngeal SCC.

METHODS

Population-based cohort study of 75,087 patients with HNSCC in the Surveillance, Epidemiology, and End Results (SEER) program. SPM risk was quantified by using standardized incidence ratios (SIRs), excess absolute risk (EAR) per 10,000 person-years at risk (PYR), and number needed to observe. Trends in SPM risk were analyzed by using joinpoint log-linear regression.

RESULTS

In patients with HNSCC, the SIR of second primary solid tumor was 2.2 (95% CI, 2.1 to 2.2), and the EAR was 167.7 cancers per 10,000 PYR. The risk of SPM was highest for hypopharyngeal SCC (SIR, 3.5; EAR, 307.1 per 10,000 PYR) and lowest for laryngeal SCC (SIR, 1.9; EAR, 147.8 per 10,000 PYR). The most common SPM site for patients with oral cavity and oropharynx SCC was HN; for patients with laryngeal and hypopharyngeal cancer, it was the lung. Since 1991, SPM risk has decreased significantly among patients with oropharyngeal SCC (annual percentage change in EAR, -4.6%; P = .03).

CONCLUSION

In patients with HNSCC, the risk and distribution of SPM differ significantly according to subsite of the index cancer. Before the 1990s, hypopharynx and oropharynx cancers carried the highest excess risk of SPM. Since then, during the HPV era, SPM risk associated with oropharyngeal SCC has declined to the lowest risk level of any subsite.

A metastasis or a second independent cancer? Evaluating the clonal origin of tumors using array copy number data

When a cancer patient develops a new tumor it is necessary to determine if it is a recurrence (metastasis) of the original cancer, or an entirely new occurrence of the disease. This is accomplished by assessing the histo-pathology of the lesions. However, there are many clinical scenarios in which this pathological diagnosis is difficult. Since each tumor is characterized by a distinct pattern of somatic mutations, a more definitive diagnosis is possible in principle in these difficult clinical scenarios by comparing the two patterns. In this article we develop and evaluate a statistical strategy for this comparison when the data are derived from array copy number data, designed to identify all of the somatic allelic gains and losses across the genome. First a segmentation algorithm is used to estimate the regions of allelic gain and loss. The correlation in these patterns between the two tumors is assessed, and this is complemented with more precise quantitative comparisons of each plausibly clonal mutation within individual chromosome arms. The results are combined to determine a likelihood ratio to distinguish clonal tumor pairs (metastases) from independent second primaries. Our data analyses show that in many cases a strong clonal signal emerges. Sensitivity analyses show that most of the diagnoses are robust when the data are of high quality.

A strategy for distinguishing optimal cancer subtypes

Much attention is directed currently to identifying subtypes of cancers that are genetically and clinically distinct. The expectation is that subtyping on the basis of somatic genomic characteristics will supplant traditional pathological subtypes with respect to relevance for targeted therapies and clinical course. Less attention has been paid to the goal of validating subtypes on the basis of the distinctiveness of their etiologies. In this article it is shown that studies of individuals with double primary malignancies provide uniquely valuable information for establishing the etiologic distinctiveness of candidate tumor subtypes. Studies of double primaries have the potential to definitively rank candidate taxonomic systems with respect to their etiological relevance by determining which subtypes are most highly correlated in the double primaries. The concept is illustrated with data from studies of the concordance of estrogen and progestin status in bilateral breast cancers, where it is shown that double primaries are much more likely to be concordant with respect to estrogen receptor (ER) status than for PR status. The high concordance of ER status is consistent with a growing literature demonstrating the etiologic distinctiveness of ER+ and ER- tumors.

Expression of inhibitor of apoptosis family proteins in human oral squamous cell carcinogenesis

BACKGROUND

The purpose of this study was to determine inhibitor of apoptosis (IAP) expression, its relationship with p53, and epigenetic change in oral carcinogenesis that remain to be elucidated.

METHODS

We measured IAP and p53 expression in 44 oral potentially malignant disorders and their corresponding malignant-transformed oral squamous cell carcinomas (OSCCs), and in 44 other non-transformed oral potentially malignant disorders. IAP and p53 expression in 10 fresh OSCCs, together with epigenetic change of their mutation, were also determined.

RESULTS

Normal mucosa did not express IAP/mutated p53. Oral potentially malignant disorders that underwent transformation exhibited high IAPs (>90%) and less-consistent mutated-p53 (34%) expression, whereas transformed OSCCs exhibited high IAP and mutated-p53 expression. Fresh OSCCs exhibited 80% to 100% IAP mRNA expression and 50% protein, mRNA, and p53 mutation expression. Normal tissues revealed DNA methylation of IAP, whereas cancerous tissues overexpressing IAP exhibited hypomethylation.

CONCLUSION

This study showed that IAP expression is an early event in oral carcinogenesis and that epigenetic and genetic pathways are associated with IAP expression in OSCC.

Detection of EBV infection and gene expression in oral cancer from patients in Taiwan by microarray analysis

Epstein-Barr virus is known to cause nasopharyngeal carcinoma. Although oral cavity is located close to the nasal pharynx, the pathogenetic role of Epstein-Barr virus (EBV) in oral cancers is unclear. This molecular epidemiology study uses EBV genomic microarray (EBV-chip) to simultaneously detect the prevalent rate and viral gene expression patterns in 57 oral squamous cell carcinoma biopsies (OSCC) collected from patients in Taiwan. The majority of the specimens (82.5%) were EBV-positive that probably expressed coincidently the genes for EBNAs, LMP2A and 2B, and certain structural proteins. Importantly, the genes fabricated at the spots 61 (BBRF1, BBRF2, and BBRF3) and 68 (BDLF4 and BDRF1) on EBV-chip were actively expressed in a significantly greater number of OSCC exhibiting exophytic morphology or ulceration than those tissues with deep invasive lesions (P = .0265 and .0141, resp.). The results may thus provide the lead information for understanding the role of EBV in oral cancer pathogenesis.

Mononuclear phagocytes in head and neck squamous cell carcinoma

The head and neck squamous cell carcinoma microenvironments contain many immune cells and their secretory products. Many of these cells belong to the mononuclear phagocyte system. The aim of this review is to study the interactions between mononuclear phagocytes and head and neck squamous cell carcinoma tissue. The role of inflammation in tumours and the cytokine interleukin-6 will be highlighted. Future therapy strategies in the treatment of head and neck cancer might be directed towards mononuclear phagocytes and their cytokine production.

Cross talk initiated by endothelial cells enhances migration and inhibits anoikis of squamous cell carcinoma cells through STAT3/Akt/ERK signaling

It is well known that cancer cells secrete angiogenic factors to recruit and sustain tumor vascular networks. However, little is known about the effect of endothelial cell-secreted factors on the phenotype and behavior of tumor cells. The hypothesis underlying this study is that endothelial cells initiate signaling pathways that enhance tumor cell survival and migration. Here, we observed that soluble mediators from primary human dermal microvascular endothelial cells induce phosphorylation of signal transducer and activator of transcription 3 (STAT3), Akt, and extracellular signal-regulated kinase (ERK) in a panel of head and neck squamous cell carcinoma (HNSCC) cells (OSCC-3, UM-SCC-1, UM-SCC-17B, UM-SCC-74A). Gene expression analysis demonstrated that interleukin-6 (IL- 6), interleukin-8 (CXCL8), and epidermal growth factor (EGF) are upregulated in endothelial cells cocultured with HNSCC. Blockade of endothelial cell-derived IL-6, CXCL8, or EGF by gene silencing or neutralizing antibodies inhibited phosphorylation of STAT3, Akt, and ERK in tumor cells, respectively. Notably, activation of STAT3, Akt, and ERK by endothelial cells enhanced migration and inhibited anoikis of tumor cells. We have previously demonstrated that Bcl-2 is upregulated in tumor microvessels in patients with HNSCC. Here, we observed that Bcl-2 signaling induces expression of IL-6, CXCL8, and EGF, providing a mechanism for the upregulation of these cytokines in tumor-associated endothelial cells. This study expands the contribution of endothelial cells to the pathobiology of tumor cells. It unveils a new mechanism in which endothelial cells function as initiators of molecular crosstalks that enhance survival and migration of tumor cells.

Chromosomal Numerical Aberrations in Oral Lichen Planus

The malignant potential of oral lichen planus (OLP) has been a matter of serious controversy. We aimed to detect chromosomal numerical aberrations in cells of brush samples collected from affected mucosa. The samples were simultaneously analyzed for morphology and fluorescent in situ hybridization (FISH) with chromosomes 2 and 8 centromeric probes. We analyzed 57 persons with OLP and 33 control individuals. A cut-off value of aneuploid cells was determined as 1.1%. Aneuploid cells were found in 16 persons with OLP (28.1%); in 10 individuals (17.5%), over 5% of the cells were aneuploid. Aneuploid cells were also detected in normal-looking mucosa of seven persons with OLP. One person with OLP developed squamous cell carcinoma; 10% of the cells examined were aneuploid. OLP carries an increased risk for chromosomal instability. Identifying aneuploid cells in a brush sample and the combined morphological and FISH analysis can increase the specificity in predicting the malignant potential of OLP.

Evaluation of the clonal origin of multiple primary melanomas using molecular profiling

Numerous investigations have been conducted using molecular profiling to evaluate the possible clonal origin of second malignancies in various cancer types. However, to date no study assessing clonality of multiple primaries has been conducted in melanoma. In this investigation using patients treated at a specialist melanoma treatment center, we compared the somatic mutational profiles of pairs of melanomas designated as independent on the basis of thorough assessment of their clinical and pathologic characteristics. We used a set of highly polymorphic genetic markers selected on the basis of their chromosomal positions and the frequencies of reported allelic losses at these genetic loci. Our statistical testing strategy showed no significant evidence of clonal origin of the two primaries in 17 of the 19 patients examined. The results suggest that most second melanomas designated as independent primary tumors on the basis of their clinicopathologic features are indeed independent occurrences of the disease, supporting the validity of the criteria used by experienced pathologists in distinguishing new primaries from metastases.

Impact of second primary tumors on survival in head and neck cancer: an analysis of 2,063 cases

OBJECTIVE/HYPOTHESIS

To investigate the impact of second primary tumors on prognosis for patients with head and neck squamous cell carcinoma (HNSCC).

STUDY DESIGN

Prospectively recorded data on HNSCC patients treated at an academic tertiary referral center.

METHODS

An analysis of 2,063 patients treated over a 15 year period for tumors of the upper aerodigestive tract, with a minimum follow-up of 10 years.

RESULTS

A total of 351 (17%) patients developed a second primary, mean time to diagnosis of the second tumor being more than 4 years from the date of the initial tumor. Median overall survival from the date of the first tumor among patients who later developed a second primary was 6 years versus 3 years among all other patients (P < .05). During the first 6 years after treatment of the initial tumor, cancer specific survival was better in the second primary group. After diagnosis of a second primary tumor, median survival was 12 months. A positive correlation was found between second primaries and stage I/II primary disease, low patient age, and initial tumors of the larynx and oral cavity.

CONCLUSIONS

The group of patients with the highest risk of a second primary tumor was younger patients with limited initial tumors. A high proportion of patients who later developed a second primary were complete responders after treatment of the first tumor. However, prognosis was poor after the actual diagnosis of the second primary tumor.

Dietary habits, ethanol and tobacco consumption as predictive factors in the development of esophageal carcinoma in patients with head and neck neoplasms

Patients with primary head and neck cancers have a higher risk of developing esophageal cancer. The aim of this study was to investigate esophageal cancer prevalence, its risk factors (ethanol and tobacco consumption) and dietary habits in patients with head and neck cancer. Three hundred and twenty-six adults with primary head and neck cancer were followed by a retrospective observational study in a general university hospital in Sao Paulo, Brazil. Flexible videoendoscopy with lugol chromoscopy was the method used to investigate esophageal cancer prevalence. All subjects were interviewed face-to-face, revealing detailed information about their tobacco and alcohol use, as well as their dietary habits. Thirty-six patients with esophageal cancer were diagnosed and the overall prevalence rate was 11.04%. Patients who developed second esophageal tumors had the following characteristics: earlier age of initial ethanol consumption (P < 0.05), longer duration period of ethanol consumption (P < 0.05) and higher weekly consumption rate (P < 0.05). There was an increased risk of esophageal carcinoma in those patients who both smoked and drank (P < 0.05). There was no association between carcinoma of the esophagus and dietary habits in patients who developed esophageal neoplasms, compared with those who did not. Prevalence rate of esophageal neoplasms was 11.04% in patients with head and neck carcinoma, whose ethanol consumption was associated with esophageal cancer. There was an increased risk between ethanol and tobacco consumption and esophageal carcinoma development. On the other hand, there was no association regarding dietary habits between patients who developed esophageal cancer and those who did not.

Endothelial cells enhance tumor cell invasion through a crosstalk mediated by CXC chemokine signaling

Field cancerization involves the lateral spread of premalignant or malignant disease and contributes to the recurrence of head and neck tumors. The overall hypothesis underlying this work is that endothelial cells actively participate in tumor cell invasion by secreting chemokines and creating a chemotactic gradient for tumor cells. Here we demonstrate that conditioned medium from head and neck tumor cells enhance Bcl-2 expression in neovascular endothelial cells. Oral squamous cell carcinoma-3 (OSCC3) and Kaposi's sarcoma (SLK) show enhanced invasiveness when cocultured with pools of human dermal microvascular endothelial cells stably expressing Bcl-2 (HDMEC-Bcl-2), compared to cocultures with empty vector controls (HDMEC-LXSN). Xenografted OSCC3 tumors vascularized with HDMEC-Bcl-2 presented higher local invasion than OSCC3 tumors vascularized with control HDMEC-LXSN. CXCL1 and CXCL8 were upregulated in primary endothelial cells exposed to vascular endothelial growth factor (VEGF), as well as in HDMEC-Bcl-2. Notably, blockade of CXCR2 signaling, but not CXCR1, inhibited OSCC3 and SLK invasion toward endothelial cells. These data demonstrate that CXC chemokines secreted by endothelial cells induce tumor cell invasion and suggest that the process of lateral spread of tumor cells observed in field cancerization is guided by chemotactic signals that originated from endothelial cells.

Comparison of properties of tests for assessing tumor clonality

SUMMARY

In a recent article Begg et al. (2007, Biometrics 63, 522-530) proposed a statistical test to determine whether or not a diagnosed second primary tumor is biologically independent of the original primary tumor, by comparing patterns of allelic losses at candidate genetic loci. The proposed concordant mutations test is a conditional test, an adaptation of Fisher's exact test, that requires no knowledge of the marginal mutation probabilities. The test was shown to have generally good properties, but is susceptible to anticonservative bias if there is wide variation in mutation probabilities between loci, or if the individual mutation probabilities of the parental alleles for individual patients differ substantially from each other. In this article, a likelihood ratio test is derived in an effort to address these validity issues. This test requires prespecification of the marginal mutation probabilities at each locus, parameters for which some information will typically be available in the literature. In simulations this test is shown to be valid, but to be considerably less efficient than the concordant mutations test for sample sizes (numbers of informative loci) typical of this problem. Much of the efficiency deficit can be recovered, however, by restricting the allelic imbalance parameter estimate to a prespecified range, assuming that this parameter is in the prespecified range.

Mechanisms of field cancerization in the human stomach: the expansion and spread of mutated gastric stem cells

BACKGROUND & AIMS

How mutations are established and spread through the human stomach is unclear because the clonal structure of gastric mucosal units is unknown. Here we investigate, using mitochondrial DNA (mtDNA) mutations as a marker of clonal expansion, the clonality of the gastric unit and show how mutations expand in normal mucosa and gastric mucosa showing intestinal metaplasia. This has important implications in gastric carcinogenesis.

METHODS

Mutated units were identified by a histochemical method to detect activity of cytochrome c oxidase. Negative units were laser-capture microdissected, and mutations were identified by polymerase chain reaction sequencing. Differentiated epithelial cells were identified by immunohistochemistry for lineage markers.

RESULTS

We show that mtDNA mutations establish themselves in stem cells within normal human gastric body units, and are passed on to all their differentiated progeny, thereby providing evidence for clonal conversion to a new stem cell-derived unit-monoclonal conversion, encompassing all gastric epithelial lineages. The presence of partially mutated units indicates that more than one stem cell is present in each unit. Mutated units can divide by fission to form patches, with each unit sharing an indentical, mutant mtDNA genotype. Furthermore, we show that intestinal metaplastic crypts are clonal, possess multiple stem cells, and that fission is a mechanism by which intestinal metaplasia spreads.

CONCLUSIONS

These data show that human gastric body units are clonal, contain multiple multipotential stem cells, and provide definitive evidence for how mutations spread within the human stomach, and show how field cancerization develops.

Second primary malignancies in squamous cell carcinomas of the tongue and larynx: an analysis of incidence, pattern, and outcome

BACKGROUND

Head and neck cancer patients have a higher risk of developing a second primary malignancy (SPM) than the general population. This study was conducted to identify the characteristics of SPM and its impact on survival in patients with squamous cell carcinoma of the tongue (TSCC) and larynx (LSCC).

METHODS

A retrospective study was conducted of 538 patients who were treated by surgery primarily for TSCC (n = 146) and LSCC (n = 392) from 1990 to 2000. The incidence, site, and overall survival of SPMs were evaluated.

RESULTS

Seventy-seven patients developed SPM during the follow-up period (median, 73 months), including 18 (12%) with TSCC and 59 (15%) with LSCC. Fifty-six percent of SPMs of the TSCC group appeared in the oral cavity. Among the SPMs of LSCC patients, 54% developed in the lung (31%) and larynx (24%). The 5-year overall survival after the diagnosis of SPM in the head and neck was 39%, compared to 29% for SPM in other areas (p = 0.010).

CONCLUSION

SPMs after treatment of TSCC and LSCC are similar in incidence but distinct in pattern. SPMs within the head and neck are associated with a better prognosis than those outside this area.

A novel rasH2 mouse carcinogenesis model that is highly susceptible to 4-NQO-induced tongue and esophageal carcinogenesis is useful for preclinical chemoprevention studies

We investigated the susceptibility of 4-nitroquinoline 1-oxide (4-NQO)-induced tongue carcinogenesis in male CB6F1-Tg-rasH2 @Jcl mice (Tg mice). The Tg mice were administered 4-NQO (20 p.p.m. in drinking water) for 2, 4, 6 or 8 weeks, and thereafter they were untreated up to week 24. At week 24, a higher incidence (80%) of tongue neoplasm with dysplasia was noted in the mice that received 4-NQO for 8 weeks in comparison with the other groups (20% incidence for each) treated with 4-NQO for 2, 4 and 6 weeks. Esophageal tumors also developed in the Tg mice were 4-NQO. Immunohistochemical observation revealed that the EP receptors, especially EP(1) and EP(2), expressed in the tongue and esophageal lesions induced by 4-NQO, thus suggesting the involvement of prostaglandin (PG) E(2) and EP(1,2) receptors in the tongue and esophageal carcinogenesis. Using this animal model, we investigated the potential chemopreventive ability of pitavastatin (1, 5 and 10 p.p.m. in diet for 15 weeks), starting 1 week after the cessation of 4-NQO-exposure (20 p.p.m. in drinking water for 8 weeks). Dietary pitavastatin at 10 p.p.m. significantly reduced the incidence and multiplicity of the tongue, but not esophageal neoplasms by the modulation of prostaglandin E2 biosynthesis, EP(1) and EP(2) expression and proliferation. Our results thus suggest that a rasH2 mouse model of 4-NQO-induced tongue and esophageal carcinogenesis can be utilized for investigating the pathogenesis of cancer development in these tissues and may well prove to be useful for identifying candidate cancer chemopreventive agents for the upper digestive organs.

Simultaneous gallbladder and bile duct cancers: revisiting the pathological possibilities

The pathogenesis of gallbladder cancer presenting synchronously with malignancy of the bile duct has not been clearly understood. The possible causes for the simultaneous presence of these tumors could be due to local spread, metastases, de novo multifocal origin, or as part of a field change in the extrahepatic biliary apparatus. In this article, we discuss the cases of four patients with simultaneous gallbladder and bile duct malignancies and analyze their individual pathologies to provide an explanation into the mechanisms that may play a role in such conditions.

Statistical tests for clonality

Cancer investigators frequently conduct studies to examine tumor samples from pairs of apparently independent primary tumors with a view to determine whether they share a "clonal" origin. The genetic fingerprints of the tumors are compared using a panel of markers, often representing loss of heterozygosity (LOH) at distinct genetic loci. In this article we evaluate candidate significance tests for this purpose. The relevant information is derived from the observed correlation of the tumors with respect to the occurrence of LOH at individual loci, a phenomenon that can be evaluated using Fisher's exact test. Information is also available from the extent to which losses at the same locus occur on the same parental allele. Data from these combined sources of information can be evaluated using a simple adaptation of Fisher's exact test. The test statistic is the total number of loci at which concordant mutations occur on the same parental allele, with higher values providing more evidence in favor of a clonal origin for the two tumors. The test is shown to have high power for detecting clonality for plausible models of the alternative (clonal) hypothesis, and for reasonable numbers of informative loci, preferably located on distinct chromosomal arms. The method is illustrated using studies to identify clonality in contralateral breast cancer. Interpretation of the results of these tests requires caution due to simplifying assumptions regarding the possible variability in mutation probabilities between loci, and possible imbalances in the mutation probabilities between parental alleles. Nonetheless, we conclude that the method represents a simple, powerful strategy for distinguishing independent tumors from those of clonal origin.

Macroscopic classification of superficial neoplastic lesions of the oral mucosa: a preliminary study

BACKGROUND

Careful endoscopic classification of macroscopic appearance of superficial neoplasias of the gastrointestinal tract is essential in the early detection and appropriate treatment of cancer. It has contributed to introduce minimally invasive endoscopic surgery and has significantly improved survival of patients with colon and gastric cancers. Squamous cell carcinoma of the oral cavity has been characterized, in past and present times, by poor prognosis and lack of progress in treatment outcome. Failure in diagnosing oral malignancy at an early stage is a major culprit, and the lack of a worldwide adopted classification of its macroscopic appearance, similar to that of gastrointestinal neoplasias, may have contributed to it.

AIM

To test the hypothesis that is possible to extend the diagnostic benefit of a classification based upon the macroscopic appearance of superficial tumours of the digestive tract to superficial carcinoma of the oral mucosa.

METHODS

We retrospectively examined a group of patients who developed multiple intraepithelial and early invasive malignant oral neoplasias, applying a modified version of the Paris classification of superficial GI neoplastic lesions.

RESULTS

One hundred and ten out of 116 (94.9%) of the study lesions had morphological features that accorded with the prepared classification.

CONCLUSIONS

These preliminary data suggest that most superficial early neoplastic lesions of the oral cavity can be easily detected using a well-defined classification system similar to that employed in the diagnosis of early gastrointestinal malignancy.

Detection of non-diploid cells in premalignant and malignant oral lesions using combined morphological and FISH analysis - a new method for early detection of suspicious oral lesions

Alteration in DNA content is an early event in oral carcinogenesis. We have examined oral brush samples to detect non-diploid cells (NDC) using simultaneous morphological and cytogenetic analysis. The study included 8 oral squamous cell carcinomas (OSCC), 22 premalignant lesions (OPLs), and 25 control individuals. Slides stained with Giemsa followed by FISH using chromosome 2 centromeric DNA probe, were scanned and fluorescent signals were simultaneously analyzed in parallel with the morphology. The proportion of NDC increased with the severity of the diagnosis. In two control subjects, 1-1.5% of the examined cells were NDC. Over 2% NDC were present in all OSCC cases and in 11 of the OPLs, of which, in 8 the histologic diagnosis was either epithelial hyperplasia or mild dysplasia. A significant number of NDC had normal morphology when cytomorphology and FISH were compared. Two patients with OPLs developed OSCC these patients had a significant proportion of NDC. We suggest that the combined morphological and cytogenetic analysis of cells collected by a non-invasive brush sampling can enhance early detection of potentially malignant cells.