Microsatellite instability in double cancers of the esophagus and head and neck

It is generally accepted that patients with squamous cancers of the esophagus are known to have a high risk of concomitant head and neck cancer. However, there have been only a few reports describing microsatellite instability (MSI) in patients with both esophageal squamous cell carcinoma and head and neck cancers. To evaluate the role of genetic instability in carcinogenesis in such patients, we analyzed six microsatellite loci in 21 tumors from 10 patients who had developed primary cancers of both the esophagus and the head and neck. MSI was detected in 6 out of 10 patients. In five patients with double cancer, MSI was observed at the same microsatellite loci in both the esophageal and the head and neck tumors obtained from the same individuals. These data suggest that such patients may have the same underlying defect in the mismatch repair system, providing insight into possible mechanisms for field carcinogenesis.     

Genomic dissection of the epidermal growth factor receptor (EGFR)/PI3K pathway reveals frequent deletion of the EGFR phosphatase PTPRS in head and neck cancers

Activation of the PI3K and epidermal growth factor receptor (EGFR) pathway is able to drive oncogenesis in multiple human cancers, including head and neck squamous cell carcinoma. Targeted agents such as cetuximab and erlotinib are currently used in patients with head and neck squamous cell carcinoma, but, in this disease, the genomic alterations that cause pathway activation and determine response to pharmacologic inhibition remain ill-defined. Here, we present a detailed dissection of the EGFR/PI3K pathway, composed of sequencing of the core pathway components, and high-resolution genomic copy number assessment. Mutations were found in PIK3CA (6%), but no point mutations were observed in other pathway genes such as PTEN and EGFR. In contrast, we observed frequent copy number alterations of genes in the pathway, including PIK3CA, EGFR, protein tyrosine phosphatase receptor S (PTPRS), and RICTOR. In total, activating genetic pathway alterations were identified in 74% of head and neck tumors. Importantly, intragenic microdeletions of the EGFR phosphatase PTPRS were frequent (26%), identifying this gene as a target of 19p13 loss. PTPRS loss promoted EGFR/PI3K pathway activation, modulated resistance to EGFR inhibition, and strongly determined survival in lung cancer patients with activating EGFR mutations. These findings have important implications for our understanding of head and neck cancer tumorigenesis and for the use of targeted agents for this malignancy.     

Minimal expression of the proto-oncogene int-2 encoded protein in a series of colorectal carcinomas

BACKGROUND: Int-2 (fibroblast growth factor-3) is a gene that belongs to the fibroblast growth factor gene family. It has been implicated in the carcinogenesis of several types of cancer, including esophageal squamous cell carcinoma, breast, head, and neck and lung carcinomas; but no firm data on its biological activity regarding neoplasms arising from the glandular epithelia of the gastrointestinal tract exists. METHODS: In the present immunohistochemical study, we investigated the presence of int-2 encoded protein in a panel of 80 cases of colon carcinoma of various stages, grades and sizes. A sheep antihuman int-2 antibody was applied to paraffin-embedded tissue sections from the tumor samples. The percentage of int-2 immunostaining in the positively stained specimens was evaluated by image analysis. RESULTS: Int-2 was positively detected in only four tumors (i.e. 5% of the cases examined). All immunopositive cases were moderately differentiated tumors; the adjacent mucosa did not express int-2 protein. The relevant patients were male. CONCLUSION: These findings suggest that the role of int-2 in colorectal carcinogenesis is probably a limited one.     

Autocrine epidermal growth factor receptor ligand production and cetuximab response in head and neck squamous cell carcinoma cell lines

Purpose  

Predictive strategies for the treatment efficacy of cetuximab are currently not available for head and neck cancer. We investigated the correlation between the expression of epidermal growth factor receptor (EGFR) ligands and EGFR expression, and the growth inhibitory activity of cetuximab in a panel of head and neck squamous cell carcinoma (HNSCC) cell lines.     

The biological properties of cetuximab

Cetuximab is a recombinant chimeric human murine immunoglobulin G1 antibody that binds to the extra-cellular domain of epidermal growth factor receptor with a higher affinity than either endogenous ligand. This binding inhibits receptor phosphorylation and activation and it leads to receptor internalization and degradation. Several studies have shown that cetuximab is able to inhibit growth of epidermal growth factor receptor (EGFR)-expressing tumour cells in vitro. Moreover, treatment with cetuximab results in a marked inhibition of tumour growth in nude mice bearing xenografts of human cancer cell lines. These results are linked to cetuximab biological effects as inhibition of cell cycle, tumour progression, neo-angiogenesis, invasion and metastatization, as well as increase and activation of pro-apoptotic molecules. Additionally, cetuximab potentiates, in combination, the effects of chemotherapy and radiation therapy in eradicating well-established tumours in nude mice and it may even reverse the resistance to some cytotoxic agents in these xenografts. Moreover, numerous clinical trials demonstrated cetuximab efficacy in different tumour types. It has been approved by Food and Drugs Administration in the treatment of metastatic colorectal cancer as single agent or in combination with chemotherapy, in locally and regionally advanced head and neck squamous cell carcinoma in combination with radiation, and as monotherapy for recurrent and metastatic head and neck squamous cell carcinoma after failing platinum-based chemotherapy. This paper will overview all the experimental and pre-clinical data on the biological properties of cetuximab.     

Identification of site-specific prognostic biomarkers in patients with oral squamous cell carcinoma

The purpose of the present study was to identify site-specific prognostic biomarkers in patients with oral squamous cell carcinoma (OSCC). For this purpose, Epidermal growth factor receptor (EGFR), Stat3, H-ras, c-myc, p53, cyclin D1, p16, Rb and Bcl-2 were localized immunohistochemically in buccal mucosa carcinoma (n=74) and tongue carcinoma (n=61) patients. Expression of markers was compared between buccal mucosa and tongue carcinoma and assessed for their prognostic value in site-specific manner. On comparison, only cyclin D1 showed significant difference in expression with higher accumulation in tongue tumors (r=+0.177, p=0.039). Moreover, univariate survival analysis showed that in buccal mucosa patients, loss of p16 and overexpression of H-ras were significant prognosticators for relapse-free survival (RFS) and overall survival (OS), respectively. However, in Cox multivariate analysis, they lost their significance after adjusting for significant clinicopathological parameters. On the other hand, in tongue cancer patients, Cox multivariate analysis showed that for RFS, Stat3 and c-myc, and for OS, Stat3, Bcl-2 and p53 were significant prognosticators after adjusting for significant confounding factors. Our findings indicated that buccal mucosa and tongue carcinoma exhibit different biological behavior which is reflected in prognosis. Therefore, this approach might be helpful to precisely identify patients for more effectively tailored treatment strategy.     

Requirement of matrix metalloproteinase-9 for the transformation of human mammary epithelial cells by Stat3-C

Persistently activated Stat3 is found in many different cancers, including approximately 60% of breast tumors. Here, we demonstrate that a constitutively activated Stat3 transforms immortalized human mammary epithelial cells and that this oncogenic event requires the activity of matrix metalloproteinase-9 (MMP-9). By immunohistochemical analysis, we observe a positive correlation between strong MMP-9 expression and tyrosine phosphorylated Stat3 in primary breast cancer specimens. These results demonstrate a relationship between activated Stat3 and MMP-9 in breast oncogenesis.     

Expression of survivin and caspase-3 in gastric cancer

Gastric cancer is one of the most common malignant tumors of the gastrointestinal tract. However, the molecular pathways involved in the regulation of gastric carcinogenesis are not completely elucidated. In the last decade, basic cancer research has been focused on the deregulation of apoptosis as a central event in the process of carcinogenesis. Caspase-3 and survivin are regulators of apoptosis and have been implicated in the development of gastric cancer. The aim of the present study was to compare the expression of mRNA and protein for survivin and caspase-3 in the gastric cancer and in the cancer margin with that in normal human gastric mucosa. Fifteen patients with advanced gastric cancer (all H. pylori-positive) and 15 matched control subjects with normal gastric mucosa were included in this study. The biospy specimens for histology and for molecular analyses were taken from gastric tumor, tumor surrounding gastric mucosa and in normal patients from the mucosa of antrum and corpus. Survivin mRNA expression was very weak, but detectable, in the normal gastric mucosa. However, at the protein level, no expression for survivin was detected in the normal gastric mucosa. In the biopsy specimens from tumor and surrounding gastric mucosa, a significant increase in survivin mRNA and protein expression was observed. The expression of survivin was higher in the tumor than in the tumor margin. The mRNA and protein expression of caspase-3 was detected in the gastric mucosa of normal subjects. In gastric cancer only the expression of procaspase-3 was observed, while the expression of active caspase-3 was completely undetectable. In the gastric mucosa surrounding gastric cancer, no gene and protein expression for caspase-3 was detected. We conclude that the changes in the level of caspase-3 and survivin play an important role in the transformation from normal gastric mucosa to gastric career.     

Quadruple cancer,including triple cancers in the head and neck region

Multiple primary tumors are not rare: they are encountered in 3-5% of malignant tumors. They are particularly frequent in the head and neck [20]. They are most often met with secondary malignant tumors; triple tumors occur in only 0.5%, quadruple tumors in 0.3% of malignant tumors. The possibility of developing a second metachronous cancer 5 years after undergoing treatment of the initial head and neck cancer is approximately 22%. Multiple metachronous tumors often appear 3-4 years after the observation of the primary tumor, or even after 5-10 years in the case of laryngeal tumors. The frequency of multiple primary tumors in the head and neck region supports the "field cancerization" theory, according to which the inducing agents (primarily smoking and alcohol consumption) can initiate the tumorous degeneration at a number of sites in the oropharyngeal region. The authors report on a case in whom surgery for bladder tumor was followed 101 months later by tumor development in the region of the head and neck: 3 such tumors were treated within a period of 21 months. The histologic result on the bladder tumor was transitiocellular carcinoma, while the latter ones were squamous cell carcinomas. Three of the tumors were treated effectively (no local recurrence or metastasis developed), but the fourth led to the death of the patient. The literature on multiple tumors of the head and neck is reviewed, and possible etiologic factors are discussed. It is pointed out that, besides primary and secondary prevention, close observation of these patients is required, repeated panendoscopy of the upper aerodigestive tract and genetic examinations are recommended.     

No evidence of HPV DNA in esophageal squamous cell carcinoma in a population of Southern Brazil

AIM:To investigate the association between human papillomavirus(HPV)and esophageal squamous cell carcinoma(ESCC)in southern Brazil.METHODS:We studied 189 esophageal samples from125 patients from three different groups:(1)102 biopsies from 51 patients with ESCC,with one sample from the tumor and another from normal esophageal mucosa distant from the tumor;(2)50 esophageal biopsies from 37 patients with a previous diagnosis of head and neck squamous cell carcinoma(HNSCC);and(3)37 biopsies from esophageal mucosa with normal appearance from 37 dyspeptic patients,not exposed to smoking or alcohol consumption.Nested-polymerase chain reaction(PCR)with the MY09/11 and GP5/6 L1primers was used to detect HPV L1 in samples fixed in formalin and stored in paraffin blocks.All PCR reactions were performed with a positive control(cervicovaginal samples),with a negative control(Human Genomic DNA)and with a blank reaction containing all reagents except DNA.We took extreme care to prevent DNA contamination in sample collection,processing,and testing.RESULTS:The histological biopsies confirmed the diagnosis of ESCC in 52 samples(51 from ESCC group and 1 from the HNSCC group)and classified as well differentiated(12/52,23.1%),moderately differentiated(27/52,51.9%)or poorly differentiated(7/52,13.5%).One hundred twenty-eight esophageal biopsies were considered normal(51 from the ESCC group,42 from the HNSCC group and 35 from dyspeptic patients).Nine had esophagitis(7 from the HNSCC and 2 from dyspeptic patients).Of a total of 189 samples,only 6 samples had insufficient material for PCR analysis:1 from mucosa distant from the tumor in a patient with ESCC,3from patients with HNSCC and 2 from patients without cancer.In 183 samples(96.8%)GAPDH,G3PDH and/orβ-globin were amplified,thus indicating the adequacy of the DNA in those samples.HPV DNA was negative in all the 183 samples tested:52 with ESCC,9 with esophagitis and 122 with normal esophageal mucosa.CONCLUSION:There was no evidence of HPV infection in different ESCC from southern Br