Multistep laryngeal carcinogenesis helps our understanding of the field cancerisation phenomenon: a review

Serum and tissue expression of neuropilin 1 in precancerous and malignant vocal fold lesions

Objectives

The study was designed to evaluate the tissue expression of NRP-1 and serum level of sNRP-1 in the same patients with intraepithelial laryngeal lesions or early staged laryngeal cancer to identify the clinical significance of these biomarkers in the diagnosis of laryngeal lesions.

Material and methods

A prospective analysis of tissue was performed on specimens and blood samples from 49 patients, who were admitted for surgical resection due to suspicious vocal fold lesions and were diagnosed as non-dysplasia, low-grade dysplasia, high-grade dysplasia and invasive cancers.

Results

ELISA was conducted on 48 blood samples. The minimum level of sNRP-1 was 0.15 ng/ml and maximum– 37.71 ng/ml. The Kruskal–Wallis one-way analysis of variance revealed no differences in sNRP-1 levels between different histopathological stages of vocal fold lesions (p = 0.234). IHC was conducted in 49 tissue samples. The evaluated mean scores of NRP-1 tissue expression were compared to histopathological stage of the lesion. The Kruskal–Wallis one-way analysis of variance revealed no differences in NRP-1 tissue expression between different histopathological stages of vocal fold lesions (p = 0.536). The correlation of tissue NRP-1 expression and serum levels of NRP-1 within analyzed group was insignificant. The Spearman’s rank correlation coefficient was 0.076 (p = 0.606).

Conclusions

The NRP-1 tissue expression and serum levels are unlikely to be a prognostic factor for identification of laryngeal dysplasia or early stage laryngeal cancer. Further studies investigating biomolecules involved in laryngeal carcinogenesis are necessary.

[Synchronous carcinoma of the floor of mouth carcinoma with esophageal carcinoma: a case report]

This study presents a case of synchronous multiple primary cancers involving floor of mouth carcinoma with esophageal carcinoma. Literature was reviewed to summarize the incidence, location, diagnosis, treatment characteristics, and prognosis to improve understanding and awareness of the multiple primary cancer. As a result, early discovery, early diagnosis, and effective treatment can help prolong survival and improve the quality of life of patients.

Mutational Status of CDKN2A and TP53 Genes in Laryngeal Squamous Cell Carcinoma

Laryngeal squamous cell carcinoma (LSCC) is the second most common tumour of the head and neck. It is characterized by frequent aberrations in two cell-cycle regulators--CDKN2A and TP53. However, LSCC has been often studied as a part of the group of head and neck cancers and not as an individual entity. In the current study we aimed to examine mutation status of CDKN2A and TP53 genes in 108 LSCC patients. DNA was extracted from fresh-frozen tumour tissues; exons 1-3 of CDKN2A and exons 5-8 of TP53 were screened for mutations by direct sequencing. Genetic aberrations in CDKN2A were found in 16 (14.2%) and those in TP53--in 56/108 (51.9%) tumours. Seven mutations (two insertions, three deletions, one missense and one silent) detected in CDKN2A were not described previously. Also, we found seven novel deletions and a novel indel in TP53. No significant associations with clinical features were found. However, TP53 mutations were predominantly observed in smokers with advanced stage tumours. Screening for genetic aberrations in a defined group of LSCC contributes to the knowledge about laryngeal carcinogenesis. Further investigations are required to confirm the observed trends in associations with clinical features.

RNA interference (RNAi) mediated stable knockdown of protein casein kinase 2-alpha (CK2α) inhibits migration and invasion and enhances cisplatin-induced apoptosis in HEp-2 laryngeal carcinoma cells

Laryngeal carcinoma is a common malignant neoplasm occurring in the head and neck, threatening human health. Protein casein kinase 2-alpha (CK2α) has been indicated to participate in the pathogenesis of this cancer; however, the underlying mechanisms still need to be elucidated. In this study, short hairpin RNA (shRNA)-mediated RNA interference (RNAi) technology was utilized to inhibit the CK2α expression in HEp-2 laryngeal carcinoma cells. Results showed that both mRNA and protein expression levels of endogenous CK2α were markedly decreased in HEp-2 cells transfected with CK2α specific shRNA. Transwell assays revealed that stable knockdown of CK2α significantly inhibited the migration and invasion of HEp-2 cells. As compared with cells treated with negative control shRNA, epithelial cadherin (E-cadherin) expression was increased, but snail, slug and vimentin were decreased in cells transfected with CK2α shRNA, indicating that inhibition of CK2α expression may suppress the epithelial-mesenchymal transition (EMT) process of laryngeal carcinoma in vitro. Moreover, suppression of CK2α was found to enhance the apoptosis induced by cisplatin in laryngeal carcinoma cells, probably through inhibition of permeability glycoprotein (P-glycoprotein) and multidrug-resistance protein (MRP1). In conclusion, our study may provide a promising therapeutic strategy for human laryngeal carcinoma by targeting CK2α.

Clinical history, prognostic factors, and management of facial nerve in malignant tumors of the parotid gland

OBJECTIVES

We analyzed the outcomes following clinical management of parotid masses that were determined to be malignant tumors after parotidectomy.

METHODS

We evaluated data from 70 patients with parotid malignancies between November 1994 and December 2005.

RESULTS

Among salivary histotypes (n=49), the most significant prognostic parameter was cT4 stage at diagnosis (P=0.0055, log-rank) both for clinical involvement of the facial nerve and for invasion of other structures. The main cause of cancer-related death was a distant metastasis.

CONCLUSION

The present series confirms that the main prognostic parameter in salivary parotid malignancies was cT4 classification at diagnosis, often due to clinical involvement of the facial nerve. The oncological outcome of salivary malignancies was influenced by distant metastasis more than most other head and neck sites. We recommend dissecting and preserving the functioning VIIth cranial nerve during surgery for parotid malignancies.

Genetic variants in p53-related genes confer susceptibility to second primary malignancy in patients with index squamous cell carcinoma of head and neck

Because of their important roles in mediating the stabilization and expression of p53, we hypothesized that high-risk genotypes of polymorphisms in p53-related genes, including p53, p73, p14(ARF), MDM2 and MDM4, may be associated with an increased risk of second primary malignancy (SPM) after index squamous cell carcinoma of the head and neck (SCCHN). We analyzed data from a cohort of 1283 patients with index SCCHN who were recruited between 1995 and 2007 at MD Anderson Cancer Center and followed for SPM development. Patients were genotyped for nine polymorphisms of p53-related genes. A log-rank test and Cox models were used to compare SPM-free survival and risk. Our results demonstrated that each p53-related polymorphism had a moderate effect on increased SPM risk, but when we combined risk genotypes of these nine polymorphisms together, we found that SPM-free survival was significantly shorter among risk groups with a greater number of combined risk genotypes. SPM risk increased with increasing number of risk genotypes (P < 0.0001 for trend). Compared with the low-risk group (0-3 combined risk genotypes), both the medium-risk (4-5 combined risk genotypes) and high-risk (6-9 combined risk genotypes) groups had significantly increased SPM risk [hazard ratio (HR): 1.6; 95% confidence interval (CI): 1.0-2.6 and HR: 3.0; 95% CI: 1.8-5.0, respectively]. Moreover, such significant associations were even higher in several subgroups. Our findings suggest that combined risk genotypes of p53-related genes may jointly modify SPM risk, especially in patients who are smokers and those with index non-oropharyngeal cancers. However, larger studies are needed to validate our findings.

Genetic profile of second primary tumors and recurrences in head and neck squamous cell carcinomas

BACKGROUND

Second primary tumors and recurrences are an important problem in patients with head and neck squamous cell carcinoma. The purpose of this study was to determine the genetic changes in tumor samples to improve knowledge of tumor progression.

METHODS

Copy number changes of 37 genes were analyzed by multiplex ligation-dependent probe amplification (MLPA) in 36 primary tumors and their corresponding 21 second primary tumors and 15 recurrences.

RESULTS

CCND1 and EMS1 amplifications and gain of BCL2L1 were the most common genetic alterations in the primary tumor, second primary tumor, and recurrence samples. Gains of ERBB2 and PTPN1 were associated with recurrences.

CONCLUSION

Specific genetic profiles for each group have been found. Similarities between primary tumor and second primary tumor and dissimilarity between primary tumor and recurrence suggest that clinicopathological criteria do not always accurately differentiate these entities. Genetic profiling may aid in the diagnosis and prognosis of these difficult cases.

Genetic model of transformation and neoplastic progression in laryngeal epithelium

BACKGROUND

The aim of this study was to analyze genetic alterations in the transformation-progression model of laryngeal tumors.

METHODS

Copy number changes of 37 genes were analyzed by multiple ligation-dependent probe amplification (MLPA) in 94 tissue samples.

RESULTS

In the smoker normal mucosa group TP53 loss was predominant, whereas in the precursor lesions CDKN2A loss and CDKN2D gain were most frequent. Precursor lesions with progression presented CTNNB1 loss. In the carcinoma group the most common changes were CDKN2A, MLH1, CTNNB1, and CASP6 losses and RECQL4, CCND1, and EMS1 gains. Positive lymph node primary tumors were related to TP53, IL1A, and RB1 losses and STK11 gain. The lymph node metastases differed from their corresponding primary tumor in LMNA, RECQL4, and IGF1R losses, and N33 and CDKN2D gains.

CONCLUSIONS

Genetic changes and new key genes were found to be associated with specific steps. We included new steps, not presented in the classic models: normal mucosa tobacco exposed, positive lymph node primary tumor, and corresponding lymph node metastases.

The molecular biology of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are caused by tobacco and alcohol consumption and by infection with high-risk types of human papillomavirus (HPV). Tumours often develop within preneoplastic fields of genetically altered cells. The persistence of these fields after treatment presents a major challenge, because it might lead to local recurrences and second primary tumours that are responsible for a large proportion of deaths. Aberrant signalling pathways have been identified in HNSCCs and inhibition of epidermal growth factor receptor (EGFR) has proved a successful therapeutic strategy. In this Review, we discuss the recent literature on tumour heterogeneity, field cancerization, molecular pathogenesis and the underlying causative cancer genes that can be exploited for novel and personalized treatments of patients with HNSCC.

The molecular biology of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are caused by tobacco and alcohol consumption and by infection with high-risk types of human papillomavirus (HPV). Tumours often develop within preneoplastic fields of genetically altered cells. The persistence of these fields after treatment presents a major challenge, because it might lead to local recurrences and second primary tumours that are responsible for a large proportion of deaths. Aberrant signalling pathways have been identified in HNSCCs and inhibition of epidermal growth factor receptor (EGFR) has proved a successful therapeutic strategy. In this Review, we discuss the recent literature on tumour heterogeneity, field cancerization, molecular pathogenesis and the underlying causative cancer genes that can be exploited for novel and personalized treatments of patients with HNSCC.

Frequent hypermethylation of DAPK, RARbeta, MGMT, RASSF1A and FHIT in laryngeal squamous cell carcinomas and adjacent normal mucosa

Laryngeal cancers are the most frequent cancers of the head and neck region. While recent observations indicate the occurrence of an epigenetic field defect in head and neck cancer patients, a detailed exploration of the characteristic changes in the DNA methylation profile in laryngeal cancer patients was lacking. The aim of this study was to assess the methylation frequency of seven genes in a group of patients with primary laryngeal squamous cell carcinoma. Along tumor sections, matching samples of normal mucosa from epiglottis and trachea were analyzed. Gene methylation was assessed using the methylation-specific polymerase chain reaction. We found frequent gene hypermethylation in both the tumor and normal mucosa samples. The methylation of MGMT in tumor cells was associated with lymph node involvement. We report that laryngeal squamous cell carcinomas are characterized by frequent hypermethylation of DAPK, RARbeta, MGMT, RASSF1A and FHIT. Moreover, evidence is shown for the occurrence of a large epigenetically changed field of epithelial cells in laryngeal cancer patients. Our findings indicate the high prevalence of epigenetic abnormalities in laryngeal tumors.

Frequent gene hypermethylation in laryngeal cancer cell lines and the resistance to demethylation induction by plant polyphenols

Promoter hypermethylation is one of the mechanisms in the transcriptional inactivation of certain carcinoma - associated genes. In laryngeal cancers hypermethylation of tumor suppressor genes is related to their major risk factors- cigarette smoking and drinking strong alcohols. Since DNA methylation is reversible, modulation of the activity of DNA methyltransferases is an established therapeutic strategy, which can be also applied in cancer chemoprevention. Here, using the MSP procedure, we evaluated the frequency of hypermethylation of RARbeta, RASSF1A, HIN-1, GSTP1, MGMT, VHL and DAPK genes in several laryngeal and other head and neck squamous cell carcinoma cell lines and the effect of various polyphenols on the methylation of RARbeta and MGMT genes in the UT-SCC 42B cell line. Most of the cell lines tested were characterized by the hypermethylation of at least one of the genes analyzed. The most frequently hypermethylated genes were RARbeta and MGMT, while GSTP1 and VHL were not methylated in any of the cell lines. None of the tested compounds, including decitabine used as a reference compound, changed the methylation of RARbeta and MGMT genes. These findings suggest that although hypermethylation of RARbeta and MGMT may be considered as potential epigenetic biomarker, their application as therapeutic/chemopreventive targets requires further studies.

Clinical significance of TRAIL and TRAIL receptors in patients with head and neck cancer

BACKGROUND

Tumor necrosis factor (TNF)-related apoptosis-inducing ligand (TRAIL) is a death ligand currently under clinical trials for cancer. The molecular profile of TRAIL and TRAIL receptors has not yet been mapped for patients with laryngeal squamous cell carcinoma (SCC) or patients with oral cavity squamous cell carcinoma (OCSCC).

METHODS

Paraffin-embedded tissues from 60 patients with laryngeal SCC and 14 patients with OCSCC were retrospectively analyzed using immunohistochemistry.

RESULTS

An increase in decoy-R1 (DcR1) but a decrease in decoy-R2 (DcR2) expression were observed in patients with laryngeal SCC and in patients with OCSCC compared with control individuals with benign lesions. Clinical and pathologic grading revealed distinctive TRAIL and TRAIL receptor profiles in patients with squamous cell carcinoma of the head and neck (SCCHN).

CONCLUSIONS

TRAIL and a TRAIL receptor expression profile might be useful to follow-up disease progression by virtue of its connection with clinical staging and pathologic grading in patients with laryngeal SCC.

Endoscopic horizontal partial laryngectomy by CO(2) laser in the management of supraglottic squamous cell carcinoma

BACKGROUND

The objective of this study was to evaluate the results of endoscopic horizontal supraglottic laryngectomy (EHSL) by CO(2) laser.

METHODS

Between 1996 and 2005, 78 patients underwent a horizontal supraglottic laryngectomy operation (HSL) with an external approach and 70 underwent laser EHSL, as treatment for supraglottic laryngeal squamous cell carcinoma (LSCC). We evaluated oncological endpoints, comparing the external and the endoscopic approach.

RESULTS

Among patients primarily treated by EHSL, the 5-year disease-specific survival (DSS) was 89% (vs 80% in the external approach group). Statistical analysis did not reveal significant differences between the 2 groups as for survival nor for organ preservation. The most significant clinical predictor for DSS is neck relapse (p < .0001).

CONCLUSIONS

This study confirms the effectiveness of laser EHSL in which oncological outcome is similar to the external approach and functional results are probably better. Neck management in this setting is fundamental to warrant the best survival.

Interactions between cells with distinct mutations in c-MYC and Pten in prostate cancer

In human somatic tumorigenesis, mutations are thought to arise sporadically in individual cells surrounded by unaffected cells. This contrasts with most current transgenic models where mutations are induced synchronously in entire cell populations. Here we have modeled sporadic oncogene activation using a transgenic mouse in which c-MYC is focally activated in prostate luminal epithelial cells. Focal c-MYC expression resulted in mild pathology, but prostate-specific deletion of a single allele of the Pten tumor suppressor gene cooperated with c-MYC to induce high grade prostatic intraepithelial neoplasia (HGPIN)/cancer lesions. These lesions were in all cases associated with loss of Pten protein expression from the wild type allele. In the prostates of mice with concurrent homozygous deletion of Pten and focal c-MYC activation, double mutant (i.e. c-MYC+;Pten-null) cells were of higher grade and proliferated faster than single mutant (Pten-null) cells within the same glands. Consequently, double mutant cells outcompeted single mutant cells despite the presence of increased rates of apoptosis in the former. The p53 pathway was activated in Pten-deficient prostate cells and tissues, but c-MYC expression shifted the p53 response from senescence to apoptosis by repressing the p53 target gene p21^Cip1. We conclude that c-MYC overexpression and Pten deficiency cooperate to promote prostate tumorigenesis, but a p53-dependent apoptotic response may present a barrier to further progression. Our results highlight the utility of inducing mutations focally to model the competitive interactions between cell populations with distinct genetic alterations during tumorigenesis.

In most human cancers, mutations are thought to arise in a single cell or few cells surrounded by their unaffected neighbors. Expansion of mutant cells can then allow the accumulation of additional mutations. The cell–cell interactions that may occur between mutant and unaffected cells or between cells with distinct mutations during tumorigenesis have not been well studied due to the lack of suitable in vivo models. To help fill this gap, we generated and characterized transgenic mice in which the oncogene c-MYC is activated focally in prostate epithelial cells. We have also analyzed mice in which prostate epithelial cells with two mutations (c-MYC overexpression and loss of Pten tumor suppressor) are found next to cells with a single mutation (loss of Pten). Although loss of Pten in the prostate is tumorigenic, it also activates a cellular senescence response which restrains further tumor progression. We found that concurrent c-MYC expression suppressed the senescence response in Pten-null cells in favor of apoptosis. c-MYC+;Pten-null cells proliferated faster than Pten-null cells in the same glands, with the net result that c-MYC+;Pten-null cells outcompete Pten-null cells. Our results demonstrate the utility of accurate models to mimic the heterogeneous and incremental nature of human prostate carcinogenesis.

Differential gene expression profiling of laryngeal squamous cell carcinoma by laser capture microdissection and complementary DNA microarrays

BACKGROUND AND AIMS

Genetic alteration associated with initiation and progression of laryngeal squamous cell carcinoma (LSCC) is largely unknown. The aim of this study was to identify genetic changes associated with the disease pathogenesis and pinpoint genes whose expression is impacted by these genetic alterations.

METHODS

Tumor cells were collected from eight matched pairs of specimens of glottic carcinoma of the larynx and histologically normal epithelium tissues adjacent to the carcinoma by laser capture microdissection (LCM). RNAs prepared from these cells were used for genome-wide transcriptome analysis by probing 16 cDNA microarrays. Real-time quantitative RT-PCR and immunohistochemistry of tissue microarrays were used to validate a group of the differentially expressed genes identified by the cDNA microarrays.

RESULTS

Hierarchical cluster analysis of the expressed genes showed that 2351 genes were differentially expressed and could distinguish cancerous and noncancerous samples. We also found 761 differentially expressed genes that were consistently different between early stage and later stage specimens. Furthermore, abnormal expression of some relevant genes such as MMP12, HMGA2, and TIMP4 were validated by real-time quantitative RT-PCR and immunohistochemistry. Analysis of gene ontology and pathway distributions then highlighted genes that may be critically important to laryngeal carcinogenesis.

CONCLUSIONS

Our results suggest that using LCM plus DNA microarray analysis may facilitate the identification of clinical molecular markers for disease and novel potential therapeutic targets for LSCC.

Genetic differences between primary larynx and pharynx carcinomas and their matched lymph node metastases by multiplex ligation-dependent probe amplification

Lymph nodes metastasis is a major risk factor related to poor survival in larynx and pharynx carcinomas. The aim of this study is to search for markers of lymph node involvement analyzing the genetic differences between primary larynx and pharynx squamous cell carcinomas and their corresponding lymph node metastases. Twenty-five primary tumors and their corresponding lymph node metastases were examined. DNA copy number changes of 37 genes were analyzed by multiplex ligation-dependent probe amplification (MLPA). Loss of CDKN2A (9p21) occurred in 14 out of 25 pairs (56%) of primary tumor and lymph node metastases. Loss of LMNA (1q21) was exclusively detected in 8 lymph node samples (32%). Loss of CTNNB1 (3p22) and gain of CDKN2D (19p13) were also significantly more frequent in lymph node metastases. Other aberrations related to lymph node metastases were loss of MFHAS1 (8p23), RECQL4 (8q24) and gain of N33 (8p22) and TP53 (17p13). Primary tumor and corresponding lymph node metastases showed common genetic changes. However, the lymph node metastases presented with a number of additional alterations. Acquisition of these alterations may play a role in lymphatic metastasis development.

Should there be more molecular staging of head and neck cancer to improve the choice of treatments and thereby improve survival?

PURPOSE OF REVIEW

Overall survival of head and neck squamous cell carcinoma patients on the whole has not dramatically improved in the last 30 years. One of the reasons is that tumour, node, metastasis classification is probably in some cases inadequate, since similar cases under a clinico-pathological point of view, may differ widely in prognosis. The most important reason for this is probably the extreme biological heterogeneity, which leads to a lack of consistency in treatment planning. The aim of the present review is to delineate the advances and the perspectives of clinical use of molecular characterization, which is an attempt to break through such molecular heterogeneity and to define, together with tumour, node, metastasis classification, homogeneous groups of patients for prognostic stratification and treatment selection.

RECENT FINDINGS

Among the markers evaluated in the last years, some have revealed particular promise. Epidermal growth factor receptor is probably the most reliable molecular marker at present, retaining its prognostic value independently from primary treatment. The p53 gene, the p53 protein being the main effector of DNA damage induced apoptosis, is probably the best predictor of radio/chemosensitivity.

SUMMARY

Even if clinical tumour, node, metastasis classification will probably retain its significance, it is now becoming possible, by molecular markers, to acquire biological information about host and tumour, to break through the above-cited molecular heterogeneity and eventually to optimize the choice of treatment.

Rationale for adjuvant fatty acid therapy to prevent radiotherapy failure and tumor recurrence during early laryngeal squamous cell carcinoma

Information from a preceding lipid study contributed to the pathobiological assessment of laryngeal squamous cell carcinoma (LSCC). Lipid-driven signaling pathways are responsible for laryngeal carcinogenesis and immunodeficiency. The construction of fatty acid (FA) profiles for LSCC allowed the identification of FA role players. The integration of lipid and clinicomolecular information encountered in the literature, in turn, allowed the identification of biological prognostic markers to distinguish between early (less aggressive) and advanced (more aggressive) LSCCs. High arachidonic acid (AA) and cyclooxygenase (COX-2) activities are criteria for less aggressive growth, whilst low AA and COX-2 activities occur during more aggressive growth. Excessive tobacco use and environmental smoke or human papillomavirus (HPV) infection and alcohol abuse can, respectively, elicit cumulative oxidative stress and an oxidative burst or interfere with signaling pathways during essential fatty acid (EFA) metabolism, all factors and events which may cause LSCC. Research revealed that enhanced COX-2 activity and Bcl-2 expression prevent apoptosis and, hence, LSCCs become resistant to radiotherapy. It was also observed that recurrent laryngeal cancers become more aggressive after radiotherapy failure. It is predicted that manipulation of AA activity and consequently a cascade of downstream factors that include COX-2 and Bcl-2 expression responsible for LSCC may have therapeutic potential to improve radiotherapy outcome during early LSCC. Adjuvant FA therapy to improve early LSCC management by counteracting radiotherapy failure and unwanted complications for further management is proposed. FA therapeutic strategies before and during radiotherapeutic courses need to be evaluated.

Genetic analysis of multifocal superficial urothelial cancers by array-based comparative genomic hybridisation

The purpose of this study was to investigate the accumulation of genetic alterations during metachronous and/or synchronous development of multifocal low-grade superficial urothelial tumours in the same patient, by using array-based comparative genomic hybridisation (array-CGH) and FGFR mutation analysis. We analysed 24 tumours (pTa-1 G1-2) from five patients. We had previously identified a clonal relationship among the tumours of each patient by microsatellite analysis. This time, unsupervised hierarchical cluster analysis revealed that the tumours from each patient were clustered together independently of the tumours from the other patients. All of the tumours from a single patient showed a set of 2–7 identical regional or whole-arm chromosomal changes. In addition, several individual alterations were also found. Cladistic diagrams revealed that the accumulation of genetic alterations could not be explained by a linear model, and the existence of a hypothetical precursor cell was assumed in four patients. In some cases, FGFR mutation seemed to occur later during multifocal tumour development. Taken together, these findings suggest that low-grade superficial urothelial tumours accumulate minor genetic alterations during multifocal development, although these tumours are genetically stable.

Expression patterns of cyclin E, cyclin A and CDC25 phosphatases in laryngeal carcinogenesis

The aim of the research was to evaluate the expression levels of cyclin E/A and CDC25A/B during laryngeal carcinogenesis. The expression was demonstrated using immunohistochemistry in 46 cases of laryngeal cancer (LSCC), 23 epithelial dysplasias (ED) and 21 samples of normal mucosa (NM). The mean labeling indices (LI) for cyclin E in LSCC, ED and NM were 10.6, 4.9 and 0%; for cyclin A 27.2, 17.5 and 7%; for CDC25A 73.9, 53 and 32% and for CDC25B 36.5, 25.9 and 0%, respectively. A gradual increase in cyclin A and CDC25A expression levels from mild through moderate and severe dysplasia to in situ carcinoma were noted. Cyclin A LI significantly increased also from NM through ED to LSCC. Cyclin A and CDC25A LI significantly increased from NM to ED. Overexpression of cyclin A and CDC25A was significantly associated with proliferation among ED. Linear interdependency was detected in ED between the expression of CDC25A and cyclin A. Cyclin E and CDC25B overexpression occurs as a late event in neoplastic transformation. The progressive expression of proteins supports the multistep model of laryngealcarcinogenesis. The results indicate a possible role of cyclin A as a marker reflecting cell proliferation. The enhanced immunoexpression of cyclin A and CDC25A suggests the potential for malignant formation in preneoplastic lesions.

The phosphoinositide 3-kinase signalling pathway as a therapeutic target in squamous cell carcinoma of the head and neck

Squamous cell carcinoma of the head and neck (SCCHN) is associated with high morbidity and mortality. Despite significant surgical advances and refinement in the delivery of chemotherapy and radiotherapy, prognosis has improved little in recent decades. Better local control has led to the late presentation of distant metastases and novel therapeutic agents are urgently required to prevent relapse, control disseminated disease and thus improve survival. PIK3CA encodes the p110alpha isoform of phosphoinositide 3-kinase (PI3-K) and is important in SCCHN, aberrations in its activity occurring early in the oncogenic process. PI3-K signalling promotes cell survival, proliferation, invasion and angiogenesis, all contributing to tumour progression. Activation of the PI3-K pathway may also mediate resistance to chemotherapy, radiotherapy and novel therapeutic agents such as epidermal growth factor receptor inhibitors. Elements of this signalling matrix, therefore, offer attractive therapeutic targets in SCCHN as inhibition of many malignant characteristics, as well as sensitisation to multiple treatment modalities, could be anticipated.

Cancer initiation and progression: an unsimplifiable complexity

BACKGROUND

Cancer remains one of the most complex diseases affecting humans and, despite the impressive advances that have been made in molecular and cell biology, how cancer cells progress through carcinogenesis and acquire their metastatic ability is still widely debated.

CONCLUSION

There is no doubt that human carcinogenesis is a dynamic process that depends on a large number of variables and is regulated at multiple spatial and temporal scales. Viewing cancer as a system that is dynamically complex in time and space will, however, probably reveal more about its underlying behavioural characteristics. It is encouraging that mathematicians, biologists and clinicians continue to contribute together towards a common quantitative understanding of cancer complexity. This way of thinking may further help to clarify concepts, interpret new and old experimental data, indicate alternative experiments and categorize the acquired knowledge on the basis of the similarities and/or shared behaviours of very different tumours.

Pilot phase IIA study for evaluation of the efficacy of folic acid in the treatment of laryngeal leucoplakia

BACKGROUND

It has been previously observed that patients with head and neck squamous cell carcinoma or with laryngeal leucoplakia present a significant reduction in plasma folate levels. The current Phase IIA pilot study assessed the effectiveness of folic acid as a chemopreventive agent in patients affected by glottic laryngeal leucoplakia.

METHODS

Forty-three untreated patients affected by glottic laryngeal leucoplakia were enrolled in the Ear, Nose, and Throat Department (Universita Cattolica del Saco Cuore, Rome, Italy). Glottic leucoplakia was initially diagnosed by indirect laryngoscopy and successively confirmed by diagnostic direct microlaryngoscopy with a biopsy for histologic assessment. Folic acid (Folina, Schwarz Pharma, Germany) was administered orally (5 mg every 8 hours) for 6 months. Patients were monitored every 30 days by videolaryngoscopy.

RESULTS

Twelve (28%) patients had no response, 19 (44%) had a partial response, and 12 (28%) had a complete response. The mean increase in serum folate levels (10.06 +/- 0.53) and the mean decrease in homocysteine serum (3.65349 +/- 0.85526) at the end of the study were highly significant (P = .0001).

CONCLUSIONS

The larynx is 1 of the sites of major interest and a good model for the development of chemopreventive agents, but so far the proposed agents have shown no clear efficacy on precancerous lesions or on the development of second malignancies.

Progress in chemoprevention drug development: the promise of molecular biomarkers for prevention of intraepithelial neoplasia and cancer--a plan to move forward

This article reviews progress in chemopreventive drug development, especially data and concepts that are new since the 2002 AACR report on treatment and prevention of intraepithelial neoplasia. Molecular biomarker expressions involved in mechanisms of carcinogenesis and genetic progression models of intraepithelial neoplasia are discussed and analyzed for how they can inform mechanism-based, molecularly targeted drug development as well as risk stratification, cohort selection, and end-point selection for clinical trials. We outline the concept of augmenting the risk, mechanistic, and disease data from histopathologic intraepithelial neoplasia assessments with molecular biomarker data. Updates of work in 10 clinical target organ sites include new data on molecular progression, significant completed trials, new agents of interest, and promising directions for future clinical studies. This overview concludes with strategies for accelerating chemopreventive drug development, such as integrating the best science into chemopreventive strategies and regulatory policy, providing incentives for industry to accelerate preventive drugs, fostering multisector cooperation in sharing clinical samples and data, and creating public-private partnerships to foster new regulatory policies and public education.

A case-control study investigating the role of sulfotransferase 1A1 polymorphism in head and neck cancer

PURPOSE

Sulfotransferases (SULT) 1A1 detoxify and bio-activate a broad spectrum of substrates including xenobiotics. The SULT1A1 gene possesses a G-->A polymorphism that results in an Arg to His substitution at codon 213, with the His allele having a low activity. The purpose of this study was to evaluate whether SULT1A1 Arg213His polymorphisms are risk factors for head and neck squamous cell carcinoma (SCCHN).

METHODS

A total of 124 consecutive primary SCCHN patients and 249 age- and sex-matched hospital controls were enrolled in this study. Genomic DNA was isolated from peripheral blood lymphocytes and genotyping was performed by PCR-RFLP. A comprehensive epidemiological interview was conducted on all participants to collect their lifestyle data.

RESULTS

The His/His frequencies in cases and controls were 6.5% (8/123) and 3.6% (9/247), respectively (P=0.049). Multivariate logistic regression analysis showed a significant association of SCCHN and His/His genotype (OR=3.60; 95% CI=1.01-12.88). This association was stronger amongst older people, alcohol and low fruit consumers. The resulted SULT1A1 His/His genotype also associated with a higher risk of neck node positive status (OR=5.82; 95% CI=1.10-30.68).

CONCLUSIONS

These preliminary findings show for the first time that the SULT1A1 His (213) allele is a possible risk factor for head and neck cancer development.