Stromal myofibroblasts accompany modifications in the epithelial phenotype of tongue dysplastic and malignant lesions

The Immune Cells in the Development of Oral Squamous Cell Carcinoma

A still unresolved issue surrounding tumor formation concerns the role that the immune system plays in preventing the formation and progression of neoplasia, including oral squamous cell carcinoma (OSCC). Antitumor immunity has historically been seen as a critical barrier for cancer cells to develop, grow and spread, and this can be modulated using immunotherapies to achieve antitumor clinical responses. However, it has recently become clear that tumor-associated immunity, particularly the inflammatory microenvironment, has the paradoxical effect of enhancing tumorigenesis and progression. In this review, we discuss the multifaceted function of infiltrating immune cells in suppressing or promoting premalignancy and cancer. In particular, we report on the evidence supporting a role for T lymphocytes, dendritic cells, macrophages, and neutrophils in the development and progression of oral potentially malignant disorders (OPMD) and OSCC. We also draw attention to the clinical relevance of immune cell phenotypes and associated molecules for use as biomarkers and to the translatability of current research findings to improve classification systems and precision medicine in patients with OSCC.

An Immunohistochemical Analysis for Evaluating the Diagnostic Role of Myofibroblasts in Oral Squamous Cell Carcinoma using α-Smooth Muscle Actin Antibody

Background

One of the most common types of malignancies affecting the head and neck region is oral squamous cell carcinoma (OSCC). Little less is known about the role of myofibroblasts in the pathogenetic process of OSCC. Hence, we assessed the involvement of myofibroblasts in the invasive process of OSCC using α-SMA (α-smooth muscle actin) antibody.

Materials and Methods

Four study groups in total were organized as follows: 40 cases each of well-differentiated OSCC (WDOSCC), moderately differentiated OSCC (MDOSCC), poorly differentiated OSCC (PDOSCC), and controls make up Group 1, Group 2, Group 3, and Group 4, respectively. The percentage of α-SMA immunopositive cells and staining intensity (A) multiplied together to determine the final staining score (B). The final staining index was produced by multiplying staining intensity (A) by the proportion of immunopositive cells that were stained with α-SMA (B) (FSI). Score Zero was graded as Index Zero by FSI while scores One and Two received an Index Low rating, scores Three and Four an Index Moderate rating, and scores Six and Nine an Index High rating.

Results

Significantly higher expression of myofibroblast was observed in OSCC group in comparison with the control group. However; no significant difference in myofibroblast expression was observed while comparing different grades of OSCC.

Conclusion

We recommend using myofibroblasts as a stromal marker to track the severity and development of OSCC.

Is Epithelial-Mesenchymal Transition a New Roadway in the Pathogenesis of Oral Submucous Fibrosis: A Comprehensive Review

Epithelial-mesenchymal transition (EMT) collectively refers to a series of episodes that reshape polarized, intact epithelial cells into discrete motile cells that can conquer the extracellular matrix (ECM). It performs a pivotal role in embryonic development, wound healing, and tissue repair. Surprisingly, the exact mechanism can also lead to the onset of malignancy and organ fibrosis contributing to scar formation and loss of function. transforming growth factor signaling, WNT signaling, Notch signaling, Hedgehog signaling, and receptor tyrosine kinase signaling, as well as non-transcriptional changes in response to extracellular cues, such as growth factors and cytokines, hypoxia, and contact with the surrounding ECM, are responsible for the initiation of EMT.

Although the pathogenesis of oral submucous fibrosis (OSMF) is multifactorial, compelling evidence suggests that it results from collagen deregulation. EMT is one of the spotlight events in the pathogenesis of OSMF, with myofibroblasts and keratinocytes being the victim cells. EMT is an essential step in both physiological and pathological events. The importance of EMT in the malignant development of OSMF and the inflammatory reaction preceding fibrosis implies a new upcoming area of research.

This review aims to focus on the EMT events that function as a double-edged sword between wound healing and fibrosis and further discuss the mechanisms along with the molecular pathways that direct changes in gene expression essential for the same in the oral cavity. As OSMF involves a risk of malignant transformation, understanding the cellular and molecular events will open more avenues for therapeutic breakthroughs targeting EMT.

Myofibroblasts as important diagnostic and prognostic indicators of oral squamous cell carcinoma: An immunohistochemical study using alpha-smooth muscle actin antibody

Background

Oral squamous cell carcinoma (OSCC) is the most common malignancy of the oral cavity, with multifactorial etiopathogenesis. Data from the past literature suggest that myofibroblasts (MFs) can also contribute significantly to the pathogenesis of the disease. Hence, the present study was undertaken for assessing the expression of MF in well-differentiated OSCC (WDOSCC), moderately differentiated OSCC (MDOSCC), poorly differentiated OSCC (PDOSCC) and healthy controls by immunohistochemistry using alpha-smooth muscle actin (α-SMA) antibody.

Methodology

Forty cases each of WDOSCC, MDOSCC, PDOSCC and healthy controls were included. 4-μm thick sections from each tissue sample were stained with routine hematoxylin and eosin as well as immunohistochemically using α-SMA. Among different grades of OSCC, expression of MFs was compared. All the results were subjected to statistical analysis.

Results

While comparing the expression of MFs in between different grades of OSCC, nonsignificant results were obtained. While comparing the expression of MF in between OSCC cases and normal controls, significant results were obtained.

Conclusion

MFs are one of the vital pathogenetic components in OSCC cases in predicting their invasive behaviors. We advocate the use of MFs as a stromal marker for visualizing invasion and progression in OSCC patients.

Immunohistochemical evaluation of myofibroblasts in oral epithelial dysplasia and oral squamous cell carcinoma

Aim:

The aim of the study is to evaluate the presence of myofibroblasts quantitatively in oral epithelial dysplasia, oral squamous cell carcinoma (OSCC).

Materials and Methods:

Formalin-fixed, paraffin-embedded blocks were retrieved from the institutional archives. The sample size is 35 and included 15 cases of oral epithelial dysplasia (n = 15), 15 cases of squamous cell carcinoma (n = 15) and 5 cases of normal oral mucosa which served as the control (n = 5). Histologic sections were subjected to immunohistochemical analysis using alpha-smooth muscle actin, and the mean number of myofibroblasts was evaluated.

Results:

There were no myofibroblasts in the stroma of normal oral mucosa and oral epithelial dysplasia. Whereas all cases of OSCC showed myofibroblasts (mean ± standard deviation: 21.49 ± 9.76). This difference of myofibroblasts between OSCC and oral epithelial dysplasia was statistically significant with a P < 0.05. There was no statistically significant difference in the mean number of Myofibroblasts(MF) between 3 histologic grades of OSCC.

Conclusion:

The presence of myofibroblasts in the stroma of OSCC and their absence in normal oral mucosa and epithelial dysplasia reveals that these cells may play a role in cancer cell invasion and progression so the treatment strategies targeting the myofibroblasts and their by products may be beneficial in OSCC patients.

Myofibroblasts as important diagnostic and prognostic indicators of oral squamous cell carcinoma: An immunohistochemical study in normal oral mucosa, epithelial dysplasia, and oral squamous cell carcinoma

BACKGROUND

Cancer invasion is a critical step for tumor growth and its progression. The focus on epithelial changes is shifting to increasing recognition that the microenvironment makes significant contributions to tumor progression. Stromal myofibroblasts play an important role in tumor invasion and metastasis due to its ability to modify the extracellular matrix. Based on this literary evidence, we carried out an immunohistochemical study to observe the expression of myofibroblasts in oral epithelial dysplasia and oral squamous cell carcinoma (OSCC).

AIM

The aim of the study was to evaluate, compare, and correlate the presence of myofibroblasts in normal oral mucosa, oral epithelial dysplasia, and OSCC and to observe different patterns of myofibroblast arrangement using alpha-smooth muscle actin (α-SMA) as a marker, Thus assisting in early diagnosis, treatment, and prognosis of oral carcinomas.

MATERIALS AND METHODS

Thirty-six cases including 12 cases of OSCC, 12 cases of epithelial dysplasia, and 12 cases of normal oral mucosa were stained with hematoxylin and eosin to confirm the diagnosis and immunohistochemically using α-SMA antibody. The slides were evaluated for positivity and intensity of staining.

STATISTICAL ANALYSIS

The result was subjected to statistical analysis using Fisher's exact test.

RESULTS

α-SMA expression in the stroma of squamous cell carcinoma was greater than its expression in epithelial dysplasia and normal oral mucosa.

A comparative study of the frequency of myofibroblasts and macrophages between the oral and cutaneous squamous cell carcinoma

Background. Oral squamous cell carcinoma (OSCC) is among the ten most frequent malignant tumors, with SCC accounting for 94% of oral malignancies. Myofibroblasts and macrophages are multifunctional cells that have a crucial role in the biological behavior of these tumors. This study aimed to comparatively evaluate the frequency of myofibroblasts and macrophages between oral and cutaneous squamous cell carcinomas.

Methods. Sixty paraffin blocks, consisting of 20 cases of OSCC, 20 cases of CSCC, 10 cases of normal skin, and 10 cases of normal oral mucosa, were selected for this descriptive-analytical cross-sectional study. To evaluate the prevalence of myofibroblasts, α-SMA staining and CD163 markers for macrophages were used. In this study, the data were analyzed with Wilk-Shapiro test and t-test using SPSS 19. Statistical significance was set at P<0.05.

Results. The mean myofibroblast scores in CSCC and OSCC were 20.05 and 20.95, respectively, with no significant difference between the means (P>0.05). The mean macrophage scores in the skin and oral cavity were 28.125 and 49.67, respectively, with a statistically significant difference (P<0.05), indicating that the mean oral macrophage score was significantly higher than that in the skin. There was no significant difference between the presence and accumulation of macrophages and myofibroblasts between the oral and cutaneous SCCs; however, the intensity of accumulation and color pattern in OSCC and CSCC were higher than those in the normal skin and mucosa (P<0.05).

Conclusion. According to the results of this study, it appears the biological behavior of OSCC and CSCC does not depend on myofibroblasts, and other factors might be involved.

Immunoexpression of alpha smooth muscle actin correlates with serum transforming growth factor-β1 levels in oral submucous fibrosis

AIM

The aim of the present study was to correlate the immunoexpression of alpha-smooth muscle actin (α-SMA) for myofibroblasts with the serum levels of transforming growth factor-β1 (TGF-β1) in oral submucous fibrosis (OSMF).

METHODS

A total of 100 cases of histopathologically confirmed OSMF were assessed for α-SMA expression. Clinical data, such as age, sex, mouth opening, and habit history, were obtained for each case. Serum TGF-β1 levels were recorded in 73 patients with the help of enzymelinked immunosorbent assay technique.

RESULTS

The staining index of α-SMA increased concomitantly with higher myofibroblast count in the increasing histopathological grades of OSMF (P ≤ .05). Serum TGF-β1 levels were highest in the intermediate grades of OSMF. Clinical parameters, such as mouth opening, cheek flexibility, and tongue protrusion, showed a direct correlation with increasing clinical grades of OSMF.

CONCLUSIONS

The progressive increase in myofibroblasts from early to advanced stages suggests their potential use as markers for evaluating the severity of OSMF. Additionally, as myofibroblasts are responsible for producing a variety of factors that are involved in the fibrotic processes; they could be the key link in the pathogenesis of OSMF. Interruption of their development, recruitment, or activation could provide a unique therapeutic target for future treatment options in patients with OSMF.

A Comparative Immunohistochemical Study of Presence and Distribution Pattern of Stromal Myofibroblast in Oral Dysplasia and in Different Grades of Oral Squamous Cell Carcinoma

Aims and Objectives:

Squamous cell carcinoma (SCC) is a common oral malignancy with a poor survival rate. Early tumorigenesis is marked by transdifferentiation of fibroblasts to myofibroblasts (MFs), which is supported by growth factors and cytokines expressed by tumor cells. The expression of alpha-smooth muscle actin (αSMA) marker correlates with the activation of MFs. This study was undertaken to compare the frequency and distribution of αSMA immunoexpression in oral epithelial dysplasia (OED) and OSCC.

Materials and Methods:

This study was conducted on samples collected from patients with oral epithelial dysplasia and oral SCC who visited Rajarajeswari Dental College and Hospital, Bengaluru. Tissue sections were subjected to Immunohistochemistry using αSMA marker, and cells were counted. The obtained data was subjected to Kruskal–Wallis test and Mann–Whitney U-test.

Results:

On performing Kruskal–Wallis test and Mann–Whitney U-test between the three groups (normal oral mucosa, OED, and OSCC) statistically significant result was found in the frequency between OED and OSCC and between normal tissue and OSCC. On comparing the distribution pattern, statistically significant result was found between OED and OSCC and between normal tissue and OSCC.

Conclusion:

The expression of MFs increases as the disease progresses from high-grade epithelial dysplasia to invasive OSCC. Poorly differentiated SCC showed more attendance of positive MFs in the stroma than other grades of OSCC. The rise in the number of αSMA-positive MFs and change in distribution pattern in OSCC can be associated with tumor invasive characteristics. Thus, the proliferation of MFs may be used as a stromal marker of premalignancy and malignancy.

Myofibroblasts in oral potentially malignant disorders: Is it related to malignant transformation?

In oral cancer, acquisition of α-smooth muscle actin (α-SMA)-positive fibroblasts, known as myofibroblasts or carcinoma-associated fibroblasts (CAF), is an important event for progression and metastasis. However, the contribution of myofibroblasts in oral potentially malignant disorders (OPMD) remains controversial. This systematic review provides evidence that immunodetection of myofibroblasts may identify oral submucous fibrosis (OSMF) with high risk of malignant transformation, but does not represent an auxiliary tool to predict the malignant potential of leukoplakia and erythroplakia, the most common OPMD.

An Immunohistochemical and Polarizing Microscopic Study of the Tumor Microenvironment in Varying Grades of Oral Squamous Cell Carcinoma

BACKGROUND

Invasion of epithelial cells into the connective tissue brings about massive morphological and architectural changes in the underlying stroma. Myofibroblasts reorganize the stroma to facilitate the movement of tumor cells leading to metastasis. The aim of this study was to determine the number and pattern of distribution of myofibroblasts and the qualitative and quantitative change that they cause in the collagen present in the stroma in various grades of oral squamous cell carcinoma (OSCC).

METHODS

The study was divided into two groups with group I (test group, 65 cases) consisting of 29 cases of well-differentiated squamous cell carcinoma, 25 moderately differentiated SCC, and 11 poorly differentiated SCC, and group II (control group) consisting of 11 cases of normal mucosa. Sections from each sample were stained with anti-α-smooth muscle actin (α-SMA) antibodies, hematoxylin and eosin, and Picrosirius red. Several additional sections from each grade of OSCC were stained with Masson's trichrome to observe the changes in collagen. For the statistical analysis, Fisher's exact test, Tukey's post hoc honest significant difference test, ANOVA, and the chi-square test were used, and p < .05 was considered statistically significant.

RESULTS

As the tumor stage progressed, an increase in the intensity α-SMA expression was seen, and the network pattern dominated in more dedifferentiated carcinomas. The collagen fibers became thin, loosely packed, and haphazardly aligned with progressing cancer. Additionally, the mean area fraction decreased, and the fibers attained a greenish yellow hue and a weak birefringence when observed using polarizing light microscopy.

CONCLUSIONS

Myofibroblasts bring about numerous changes in collagen. As cancer progresses, there isincrease in pathological collagen,which enhances the movement of cells within the stroma.

Microenvironmental regulation of the progression of oral potentially malignant disorders towards malignancy

Oral potentially malignant disorders (OPMD) develop in a complex tissue microenvironment where they grow sustainably, acquiring oral squamous cell carcinoma (OSCC) characteristics. The malignant tumor depends on interactions with the surrounding microenvironment to achieve loco-regional invasion and distant metastases. Unlike abnormal cells, the multiple cell types in the tissue microenvironment are relatively stable at the genomic level and, thus, become therapeutic targets with lower risk of resistance, decreasing the risk of OPMD acquiring cancer characteristics and carcinoma recurrence. However, deciding how to disrupt the OPMD and OSCC microenvironments is itself a daunting challenge, since their microenvironments present opposite capacities, resulting in diverse consequences. Furthermore, recent studies revealed that tumor-associated immune cells also participate in the process of differentiation from OPMD to OSCC, suggesting that reeducating stromal cells may be a new strategy to prevent OPMD from acquiring OSCC characteristics and to treat OSCC. In this review, we discuss the characteristics of the microenvironment of OPMD and OSCC as well as new therapeutic strategies.

Immunohistochemical analysis of stromal fibrocytes and myofibroblasts to envision the invasion and lymph node metastasis in oral squamous cell carcinoma

Background:

Tumor cells work in close coordination with stromal elements from its stage of emergence to metastasis. The study was designed to assess the presence and distribution pattern of stromal fibrocytes and myofibroblasts in oral squamous cell carcinoma (OSCC). Possibility of using these stromal cells as a marker for invasion and lymphnode metastasis was evaluated.

Materials and Methods:

A total of 40 cases of OSCC consisting twenty cases of each lymph node positive (pN+) and lymph node negative (pN0) samples and ten normal oral mucosa (NOM) tissues were subjected to double immunostaining using CD34 and alpha-smooth muscle actin (α-SMA) antibodies. Stained sections were evaluated semiquantitatively.

Results:

CD34 fibrocytes were seen in 70% of NOM and none of OSCC samples. α-SMA myofibroblasts were seen in 80% of OSCC and none of NOM samples. A statistically significant difference was found in fibrocyte values (P < 0.001) and myofibroblast values (P < 0.001) between NOM and OSCC study samples. No statistical significance in myofibroblast values between pN0 and pN+ study groups; however, their distribution pattern appreciably varied.

Conclusions:

This study suggested that fibrocytes could be used as one of the markers for early invasion. Abrupt loss of fibrocytes at the transition zone toward carcinoma and statistical significance in their values supported this inference. Heterogeneity in the distribution pattern of myofibroblasts in tumor stroma indicates that this variability may predict the tumor behavior toward nodal metastasis rather than their mere presence or absence.

Physiological Fluid Flow Moderates Fibroblast Responses to TGF-β1

Fibroblasts are the major cellular component of connective tissue and experience mechanical perturbations due to matrix remodelling and interstitial fluid movement. Transforming growth factor β1 (TGF-β1) can promote differentiation of fibroblasts in vitro to a contractile myofibroblastic phenotype characterised by the presence of α-smooth muscle actin (α-SMA) rich stress fibres. To study the role of mechanical stimulation in this process, we examined the response of primary human fibroblasts to physiological levels of fluid movement and its influence on fibroblast differentiation and responses to TGF-β1. We reported that in both oral and dermal fibroblasts, physiological levels of fluid flow induced widespread changes in gene expression compared to static cultures, including up-regulation of genes associated with TGFβ signalling and endocytosis. TGF-β1, activin A and markers of myofibroblast differentiation including α-SMA and collagen IA1 were also increased by flow but surprisingly the combination of flow and exogenous TGF-β1 resulted in reduced differentiation. Our findings suggest this may result from enhanced internalisation of caveolin and TGF-β receptor II. These findings suggest that a) low levels of fluid flow induce myofibroblast differentiation and b) fluid flow antagonises the fibroblast response to pro-differentiation signals such as TGF-β1. We propose that this may be a novel mechanism by which mechanical forces buffer responses to chemical signals in vivo, maintaining a context-specific fibroblast phenotype. J. Cell. Biochem. 118: 878-890, 2017. © 2016 Wiley Periodicals, Inc.

Evaluation of Role of Myofibroblasts in Oral Cancer: A Systematic Review

Aim

To conduct a systematic review on the role of myofibroblasts in progression of oral cancer. The myofibroblast is essential for the integrity of the mammalian body by virtue of its role in wound healing, but it also plays a negative role due to their role in promoting tumor development.

Settings and design

Systematic review.

Materials and methods

Bibliographic searches were conducted in several electronic databases using all publications in PubMed, PubMed central, EMBASE, CancerLit, Google scholar, and Cochrane CCTR between 1990 and June 2015.

Results

The search of all publications from various electronic databases revealed 1,371 citations. The total number of studies considered for systematic review was 43. The total number of patients included in the studies was 990.

Conclusion

Myofibroblasts are a significant component in stroma of oral cancer cases, though not identified in all cases. This systematic review shows that clinical, pathological, and immunohistochemistry tests have correlated the presence of high myofibroblast count in oral cancer cell stroma.

Key Messages

Myofibroblasts play a significant role in oral cancer invasion and progression. Various studies have demonstrated their association with oral cancer. This review tends to highlight their role in the pathogenesis of oral cancer over the decade.

How to cite this article

Sekhon HK, Sircar K, Kaur G, Marwah M. Evaluation of Role of Myofibroblasts in Oral Cancer: A Systematic Review. Int J Clin Pediatr Dent 2016;9(3):233-239.

Comparison of Myofibroblasts Between Solid/Multicystic Ameloblastoma and Unicystic Ameloblastoma: An Immunohistochemical Analysis

INTRODUCTION

Microenvironment is crucial for the maintenance of cellular functions and tissue integrity suggesting that cancer-induced changes in the stroma may contribute to cancer invasion and its biological behaviour. One of the major constituent of the tumour stroma is myofibroblasts. Myofibroblasts are differentiated host fibroblasts that express α-Sma as cytoplasmic microfilaments. They are considered as one of the modified stromal component which in recent years have been thought to have a role in the invasion and aggressive behaviour of odontogenic tumours too.

AIM

To detect immunohistochemically the presence of myofibroblasts in solid/multicystic ameloblastoma and in unicystic ameloblastoma and to see if a relationship exists between the frequency and pattern of distribution of myofibroblasts and the behaviour of ameloblastomas.

MATERIALS AND METHODS

Ten cases each of solid/multicystic ameloblastoma and unicystic ameloblastoma were stained immunohistochemically for vimentin, α-SMA and desmin. The frequency and pattern of distribution of myofibroblasts in the two study groups were analysed and then compared with clinical and radiographic features of pain and cortical perforation respectively.

RESULTS

Immunohistochemical reaction for α-SMA (alpha Smooth Muscle Actin) showed positive cells in the stroma of both solid/multicystic and unicystic ameloblastomas. The mean number of myofibroblasts was more in unicystic ameloblastoma (UA) compared to Solid/Multicystic Ameloblastoma (SMA). Myofibroblasts expression was dense and arranged in the form of fascicles with indistinct cell borders in one case of follicular ameloblastoma, two cases of plexiform ameloblastoma and in a focal area of one case of type 1UA. In all other cases where the expression was noted, the myofibroblasts were spindle in shape with distinct cell boundaries.

CONCLUSION

The results of the study indicate that myofibroblasts alone may not play a role in the behaviour of ameloblastomas. This calls for determining the role of various other stromal components in the biological behaviour of ameloblastomas. Our study could not establish a correlation between pattern of distribution of myofibroblasts and the behaviour of ameloblastomas.

Immunohistochemical evaluation of myofibroblast density in odontogenic cysts and tumors

Background. The aim of this study was to investigate myofibroblast (MF) density in a broad spectrum of odontogenic cysts and tumors and the relation between the density of MFs and the clinical behavior of these lesions.

Methods. A total of 105 cases of odontogenic lesions, including unicystic ameloblastoma (UAM), solid ameloblastoma (SA), odontogenic keratocyst (OKC), dentigerous cyst (DC), radicular cyst (RC) (15 for each category), and odontogenic myxoma (OM), adenomatoid odontogenic tumor (AOT), calcifying odontogenic cyst (COC) (10 for each category), were immunohistochemically stained with anti-α-smooth muscle actin antibody. The mean percentage of positive cells in 10 high-power fields was considered as MF density for each case.

Results. A statistically significant difference was observed in the mean scores between the study groups (P < 0.001). The intensity of MFs was significantly higher in odontogenic tumors compared to odontogenic cysts (P < 0.001). There was no statistically significant difference between odontogenic tumors, except between UAM and OM (P = 0.041). The difference between OKC and odontogenic tumors was not statistically significant (P > 0.05). The number of MFs was significantly higher in OKC and lower in COC compared to other odontogenic cysts (P = 0.007 and P = 0.045, respectively).

Conclusion. The results of the present study suggest a role for MFs in the aggressive behavior of odontogenic lesions. MFs may represent an important target of therapy, especially for aggressive odontogenic lesions. Our findings support the classification of OKC in the category of odontogenic tumors.

Immunohistochemical expression of matrix metalloproteinase-1, matrix metalloproteinase-2 and matrix metalloproteinase-9, myofibroblasts and Ki-67 in actinic cheilitis and lip squamous cell carcinoma

Matrix metalloproteinases (MMPs), myofibroblasts (MFs) and epithelial proliferation have key roles in neoplastic progression. In this study immunoexpression of MMP-1, MMP-2 and MMP-9, presence of MFs and the epithelial proliferation index were investigated in actinic cheilitis (AC), lip squamous cell carcinoma (LSCC) and mucocele (MUC). Thirty cases of AC, thirty cases of LSCC and twenty cases of MUC were selected for immunohistochemical investigation of the proteins MMP-1, MMP-2, MMP-9, α-smooth muscle actin (α-SMA) and Ki-67. The MMP-1 expression in the epithelial component was higher in the AC than the MUC and LSCC. In the connective tissue, the expression was higher in the LSCC. MMP-2 showed lower epithelial and stromal immunostaining in the LSCC when compared to the AC and MUC. The epithelial staining for MMP-9 was higher in the AC when compared to the LSCC. However, in the connective tissue, the expression was lower in the AC compared to other lesions. The cell proliferation rate was increased in proportion to the severity of dysplasia in the AC, while in the LSCC it was higher in well-differentiated lesions compared to moderately differentiated. There were no statistically significant differences in number of MFs present in the lesions studied. The results suggest that MMPs could affect the biological behaviour of ACs and LSCCs inasmuch as they could participate in the development and progression from premalignant lesions to malignant lesions.

Cancer-associated fibroblasts provide a suitable microenvironment for tumor development and progression in oral tongue squamous cancer

Background

Oral tongue squamous cell carcinoma (OTSCC) is still associated with a poor prognosis due to local recurrence and metastasis. Cancer-associated fibroblasts (CAFs) play an important role in the complex processes of cancer stroma interaction and tumorigenesis. This study aims to determine the role of CAFs in the development and progression of OTSCC.

Methods

Immunohistochemistry was performed to evaluate the frequency and distribution of CAFs in 178 paraffin specimens from patients with OTSCC. Immunofluorescence, a cell proliferation assay, flow cytometry, migration and invasion assays and western blot analysis were used to study the effects of CAFs and the corresponding conditioned medium (CM) on the proliferation and invasion of OTSCC cell lines.

Results

Statistical analysis showed a strong correlation between the frequency and distribution of CAFs and the clinicopathological characteristics of patients with cN0 OTSCC, including pathological stage (P = 0.001), T classification (P = 0.001), and N classification (P = 0.009). Survival analysis demonstrated a negative correlation of the frequency and distribution of CAFs with the overall survival and disease-free survival of patients with cN0 tongue squamous cell cancer (P = 0.009, 0.002, respectively); Cox regression analysis showed that the presence of CAFs (relative risk: 2.113, CI 1.461–3.015, P = 0.023) is an independent prognostic factor. A functional study demonstrated that CAFs and CM from CAFs could promote the growth, proliferation, mobility, invasion and even Epithelial Mesenchymal Transition (EMT) of OTSCC cells compared with NFs and CM from NFs.

Conclusions

CAFs were an independent prognostic factor for patients with OTSCC. Compared with NFs, CAFs and their CM have the ability to promote the growth, proliferation, metastasis and even EMT of OTSCC cells.

Electronic supplementary material

The online version of this article (doi:10.1186/s12967-015-0551-8) contains supplementary material, which is available to authorized users.

Stromal myofibroblasts in potentially malignant and malignant lesions of the oral cavity

Previous studies have demonstrated that myofibroblasts in the adjacent stroma are involved in the development and progression of malignant tumors. The aim of this study was to investigate the involvement of myofibroblasts in the progression of oral squamous cell carcinomas (OSCCs) by determining myofibroblast density in potentially malignant and malignant oral lesions. A total of 69 potentially malignant oral lesions (leukoplakias with mild, moderate or severe dysplasia), 90 OSCCs (well-, moderately and poorly differentiated), eight oral verrucous carcinomas and 29 fibrous hyperplasias were examined for the presence of myofibroblasts using immunohistochemical detection of isoform α of smooth muscle actin. Myofibroblasts were not identified in the adjacent stroma of fibrous hyperplasias and potentially malignant oral lesions, whereas 59.8% of the oral carcinomas exhibited myofibroblasts in various densities. The density was significantly higher in moderately and poorly differentiated OSCCs when compared with well-differentiated tumors (P=0.04 and P=0.007, respectively). In verrucous carcinomas, the specific variant of well-differentiated OSCC, stromal myofibroblasts were not detected. The results of the present study demonstrated that immunodetection of myofibroblasts does not aid with the determination of the malignant transformation potential of oral dysplasias, although moderately and poorly differentiated tumors exhibited a significantly higher density of myofibroblasts. The results reinforce the hypothesis that myofibroblasts may contribute to oral tumorigenesis, indicating that verification and monitoring of such may serve as a putative marker of OSCC behavior.

Myofibroblast presence in apparently normal mucosa adjacent to oral squamous cell carcinoma associated with chronic tobacco/areca nut use: evidence for field cancerization

OBJECTIVE

Myofibroblasts are primary cellular components of activated tumor stroma, associated with poor prognosis in oral squamous cell carcinoma (OSCC). However, their role in field cancerization has not been addressed. This study aims to evaluate the presence of myofibroblasts in patient-matched histologically normal mucosa adjacent to oral squamous cell carcinoma (HNMAOSCC) and OSCC tissues.

MATERIALS AND METHODS

Fifty patient-matched tissues of OSCC and HNMAOSCC associated with chronic areca nut/tobacco use were subjected to immunohistochemistry using α-SMA for detection of myofibroblasts. Normal oral mucosa (n = 15) were stained as controls.

RESULTS

The number of α-SMA stained myofibroblasts in OSCC and HNMAOSCC were significantly increased as compared to that of the normal controls (p < 0.001). Further, a significant correlation was established for the presence of myofibroblasts in the stroma of OSCC and HNMAOSCC.

CONCLUSIONS

Myofibroblasts are an early stromal change in the HNMAOSCC, highlighting the possible role of myofibroblasts as likely mediators for field cancerization and their potential use as a field effect marker.

Stromal myofibroblasts in squamous cell carcinoma of the tongue in young patients - a multicenter collaborative study

OBJECTIVE

The purpose of this study was to evaluate the presence of myofibroblasts, frequently associated with a more aggressive neoplastic behavior, in oral tongue squamous cell carcinoma (TSCC) of young patients and to compare with the distribution observed in older patients.

STUDY DESIGN

Tumor samples from 29 patients younger than 40 years old affected by TSCC were retrieved and investigated for the presence of stromal myofibroblasts by immunohistochemical reactions against α smooth muscle actin, and the results obtained were compared to TSCC cases affecting older patients.

RESULTS

No positive reaction could be found in the stromal areas devoid of neoplastic tissue, whereas myofibroblasts were present in 58.6% of the lesions in young patients and in 75.9% of the older ones. No significant difference was found when comparing the invasive front and the overall stroma of both groups, and no correlation could be obtained with stromal α smooth muscle actin expression, higher tumor grades or clinical stage (P > .05).

CONCLUSION

There was no significant difference between the presence of stromal myofibroblasts of TSCC affecting young and old individuals.

Myofibroblasts in oral lesions: A review

Myofibroblasts (MFs) are modified fibroblasts that express features of smooth muscle differentiation and were first observed in granulation tissue during wound healing. These cells play a key role in physiologic and pathologic processes like wound healing and tumorigenesis. The presence of MFs has been reported in normal oral tissues and pathologic conditions like reactive lesions, benign tumors, locally aggressive tumors and malignancies affecting the oral cavity. This article briefly reviews the important hallmarks related to the discovery, characterization and tissue distribution of MFs in oral health and disease.

Evaluation of myofibroblasts by expression of alpha smooth muscle actin: a marker in fibrosis, dysplasia and carcinoma

OBJECTIVE

Evaluation of Myofibroblasts by studying expression of Alpha smooth muscle actin: A marker of Fibrosis, Dysplasia and Carcinoma.

BACKGROUND

Myofibroblasts are cells that have contractile properties and are involved in inflammation, wound healing, fibrosis and oncogenesis in most of the organs and tissues. They are involved in healing and granulation tissue formation which occur after tissue injuries, also produce inflammatory mediators, growth factors and help in extracellular matrix reorganization by secretion of proteins like collagen, fibronectin, etc. Because of their component, Alpha smooth muscle actin ([alpha]-SMA), they are involved in the contraction of extracellular matrix and aid in tissue contraction. The myofibroblasts disappear by apoptosis after completion of repair, but their persistence causes a dysfunction in the repair mechanism, leading to excessive contraction and extracellular matrix (ECM) secretion and thus, fibrosis. The purpose of this study was to evaluate the presence of myofibroblasts in cases of Oral Submucous fibrosis (OSMF), which consisted of very early, early and moderately advanced OSMF, OSMF with dysplasia and oral squamous cell carcinoma (OSCC), by detecting (alpha)-SMA, which is a specific marker for myofibroblasts.

MATERIALS AND METHODS

The study sample consisted of three groups which comprised of 41 cases of OSMF, 10 cases of OSMF with dysplasia and 11 cases of OSCC. All the cases were subjected to immunohistochemistry by using (alpha)-SMA antibody for detection of myofibroblasts.

RESULTS

The presence of myofibroblasts was significantly higher in oral squamous cell carcinomas as compared to that in OSMF with dysplasia and OSMF. A statistical significance was also noted between the staining index and age of the individuals and the staining index and duration of the habit.

CONCLUSION

Myofibroblasts play a role in fibrosis, as was seen in OSMF. Activated myofibroblasts secrete proteolytic enzymes and cause matrix degradation, which is instrumental in cancer cell invasion and metastasis. Further studies in which the myofibroblasts are targetted, may help in providing therapeutic regimens in fibrosis, dysplasia and cancer.

Activin A immunoexpression as predictor of occult lymph node metastasis and overall survival in oral tongue squamous cell carcinoma

BACKGROUND

The presence of regional lymph node metastasis has an important impact on clinical management and prognostication of patients with oral tongue squamous cell carcinoma (SCC). Approximately 30% to 50% of patients with oral tongue SCC have regional metastasis at diagnosis, but the limited sensibility of the current diagnostic methods used for neck staging does not allow detection of all cases, leaving a significant number of undiagnosed metastasis (occult lymph node metastasis). In this study, we evaluated whether clinicopathologic features and immunohistochemical detection of carcinoma-associated fibroblasts (CAFs) and activin A could be predictive markers for occult lymph node metastasis in oral tongue SCC.

METHODS

One hundred ten patients with primary oral tongue SCC, who were classified with early stage tumor (stage I and II) and received surgical treatment with elective neck dissection, were enrolled in the study.

RESULTS

Among all examined features, only high immunohistochemical expression of activin A was significantly associated with presence of occult lymph node metastasis (p = .006). Multivariate survival analysis using the Cox proportional hazard model showed that the expression of activin A was an independent marker of reduced overall survival with a 5-year survival of 89.7% for patients with low expression compared to 76.5% for those with high expression (hazard ratio [HR], 2.44; 95% confidence interval [CI], 1.55-3.85; p = .012).

CONCLUSION

Our results demonstrated that immunodetection of activin A can be useful for prognostication of oral tongue SCC, revealing patients with occult lymph node metastasis and lower overall survival.

α-Smooth muscle actin-positive myofibroblasts, in association with epithelial-mesenchymal transition and lymphogenesis, is a critical prognostic parameter in patients with oral tongue squamous cell carcinoma

BACKGROUND

α-Smooth muscle actin (α-SMA)-positive myofibroblasts play a pivotal role in progression and metastasis of solid carcinomas. Epithelial-mesenchymal transition (EMT) of cancer cells and lymphogenesis of tumor microenvironment are the important events in tumor metastasis. This study aimed to investigate the relationship between the expression of myofibroblasts marker, α-SMA, and clinicopathological features, EMT, lymphogenesis, and prognostic status in oral tongue squamous cell carcinoma (OTSCC).

METHODS

Immunohistochemisty was used to detect α-SMA expression in 50 OTSCCs. EMT and lymphogenesis were also identified by immunostaining with N-cadherin, vimentin, and lymphatic vessel endothelial hyaluronan receptor 1 (LYVE-1).

RESULTS

There was a significant correlation respectively between the α-SMA (P = 0.002), vimentin (P < 0.001), N-cadherin (P = 0.025) expression and cervical lymph node metastasis of OTSCC. Carcinomas with α-SMA (P = 0.001), vimentin (P = 0.003), and N-cadherin (P = 0.012) expression were more advanced in terms of tumor-node-metastases status. Univariate analysis showed that pathologic node status (P < 0.001), α-SMA (P = 0.001), and vimentin expression (P = 0.044) was significantly associated with overall survival time, but multivariate analysis just showed the α-SMA expression (P = 0.008) and pathologic node status (P = 0.003) was independently predictive of prognosis. Furthermore, statistical analysis showed significant correlation between α-SMA expression and vimentin (P = 0.037), N-cadherin (P = 0.019), or LYVE-1 positive vessel count (P = 0.041).

CONCLUSION

Our results indicate that α-SMA-positive myofibroblasts have important impacts on cancer progression, metastasis, and survival prognosis of patients with OTSCC. The functions of α-SMA-positive myofibroblasts in OTSCC may be associated with promoting EMT of tumor cells and lymphogenesis of metastasis microenvironment.

Stromal myofibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma: An immunohistochemical study

BACKGROUND AND AIMS

Myofibroblasts are one of the important components of the tumor microenvironment which could possibly play an important role in tumor progression. The purpose of this study was to compare the presence of α-smooth muscle actin (α-SMA) and CD34 positive fibroblasts in nonmetastatic and metastatic oral squamous cell carcinoma and to evaluate their role in tumor metastasis.

MATERIALS AND METHODS

Ten cases each of histologically proven metastatic and nonmetastatic oral squamous cell carcinoma formed the study group. The tissue sections were stained immunohistochemically for α-SMA and CD34. The stromal spindle cells positive for these markers in the study groups were counted and compared.

RESULTS

α-SMA positive cases were more in the metastatic group and CD34 positive cases were found to be more in the nonmetastatic tumors.

CONCLUSIONS

Though difference in the staining pattern was statistically nonsignificant, the inverse relationship between α-SMA and CD34 positive cells is indicative of dynamic nature and the influence of tumor stroma in tumor progression and metastasis.

Analysis of metallothionein and vimentin immunoreactivity in pharyngeal squamous cell carcinoma and its microenvironment

Metallothionein (MT) has been shown to have pro-proliferative anti-apoptotic activity and to be involved in microenvironment remodeling. The aim of this study has been to determine whether the changes in MT and vimentin immunoreactivity observed in cancer and its microenvironment are related to the local spread of the disease. The immunoreactivity levels of both MT and vimentin were evaluated together with CD56 and CD57 antigens in 49 tissue samples taken from patients with squamous cell carcinoma originating from the palatine tonsils and in 20 tissue samples derived from patients with chronic tonsillitis (the reference group). MT immunoreactivity levels were statistically significantly higher in the tissue samples from squamous cell carcinoma than in those of the reference group and also higher in the squamous cell carcinoma samples compared with the stromal samples. Moreover, stromal fibroblasts exhibited high vimentin and MT immunoreactivity levels. Statistically significantly higher MT immunoreactivity levels within the tumor cells were identified in patients with the presence of lymph node metastases in contrast to those patients without such metastases. Vimentin was detected in both the tumor and the stromal tissue samples and presented an interesting pattern of staining strongly expressed within the stroma and the septal architecture of the tumor. The number of CD56- and CD57-positive lymphocytes identified in tissue samples both from squamous cell carcinoma and from the stroma was statistically significantly lower than that in the reference group. MT expression by tumor cells is thus associated with an aggressive phenotype of the tumor and the ability to create metastases.

Warburg meets autophagy: cancer-associated fibroblasts accelerate tumor growth and metastasis via oxidative stress, mitophagy, and aerobic glycolysis

SIGNIFICANCE

Here, we review certain recent advances in oxidative stress and tumor metabolism, which are related to understanding the contributions of the microenvironment in promoting tumor growth and metastasis. In the early 1920s, Otto Warburg, a Nobel Laureate, formulated a hypothesis to explain the "fundamental basis" of cancer, based on his observations that tumors displayed a metabolic shift toward glycolysis. In 1963, Christian de Duve, another Nobel Laureate, first coined the phrase auto-phagy, derived from the Greek words "auto" and "phagy," meaning "self" and "eating."

RECENT ADVANCES

Now, we see that these two ideas (autophagy and aerobic glycolysis) physically converge in the tumor stroma. First, cancer cells secrete hydrogen peroxide. Then, as a consequence, oxidative stress in cancer-associated fibroblasts drives autophagy, mitophagy, and aerobic glycolysis.

CRITICAL ISSUES

This "parasitic" metabolic coupling converts the stroma into a "factory" for the local production of recycled and high-energy nutrients (such as L-lactate)-to fuel oxidative mitochondrial metabolism in cancer cells. We believe that Warburg and de Duve would be pleased with this new two-compartment model for understanding tumor metabolism. It adds a novel stromal twist to two very well-established cancer paradigms: aerobic glycolysis and autophagy.

FUTURE DIRECTIONS

Undoubtedly, these new metabolic models will foster the development of novel biomarkers, and corresponding therapies, to achieve the goal of personalized cancer medicine. Given the central role that oxidative stress plays in this process, new powerful antioxidants should be developed in the fight against cancer.

Comparison of myofibroblasts expression in oral squamous cell carcinoma, verrucous carcinoma, high risk epithelial dysplasia, low risk epithelial dysplasia and normal oral mucosa

The aim was to evaluate and compare the presence of myofibroblasts in oral squamous cell carcinoma (OSCC), verrucous carcinoma (VC), high-risk epithelial dysplasia (HRED), low-risk epithelial dysplasia (LRED), and normal oral mucosa (NOM). The study consisted of 37 OSCC, 15 VC, 15 HRED, 15 LRED and 15 NOM. α-smooth muscle actin (α-SMA) antibody was used to identify myofibroblasts. The α-SMA expression was not observed in NOM and LRED. The α-SMA was expressed in 97.29% of OSCC, 86.66% of VC, 46.66 % of HRED. The α-SMA expression was significantly higher in OSCC than VC (p = 0.023) and HRED (p < 0.000). The α-SMA expression was significantly higher in VC than HRED (p = 0.043). Myofibroblastic expression, as highlighted by α-SMA, is undetectable in NOM and LRED but increases as the disease progresses from potentially malignant disorders, as HRED to VC to invasive OSCC. Thus, proliferation of myofibroblasts may be used as a stromal marker of oral premalignancy and malignancy.

Significance of myofibroblasts in oral squamous cell carcinoma

It is now recognized that the tumor microenvironment makes significant contribution to tumor progression. Activated fibroblast endothelial cells, inflammatory cells, and various extra cellular matrix components are parts of this microenvironment. Most of the activated fibroblasts are α-smooth muscle actin-positive myofibroblast that often represent the majority of tumor stromal cells. Their production of growth factors chemokines and extracellular matrix facilitates tumor growth. Myofibroblast have been demonstrated in close to 50% of oral squamous cell carcinomas. In this review, we highlight the histological distribution of myofibroblast in oral squamous cell and the myofibroblast relation to tumor growth on prognosis.

The Potential Role of MT and Vimentin Immunoreactivity in the Remodeling of the Microenvironment of Parotid Adenocarcinoma

A tumor stimulates the remodeling of its microenvironment in order to control and accelerate its own growth and to initiate metastases. To create metastases the tumor cells must first acquire the ability to detach from the main tumor and to adhere to, invade, and degrade the adjacent extracellular matrix. The cells must then be able to enter the lumen of the vessels where they home the distant tissues and organs by forming secondary tumors. The acquisition of this phenotype is related to the phenomenon of epithelial-to-mesenchymal transition. On the molecular level, this process is typified by a change in the expression of epithelial markers and by the enhancement of the expression of mesenchymal markers like vimentin that are responsible for cell migration and invasion. Metallothioneins have been shown to help protect against apoptosis. The expression of MT by tumor cells plays an important and complex role not only because of its pro-proliferative, anti-apoptotic activity, but also because it inhibits the immune response. The aim of the present study was to evaluate the immunoreactivity of vimentin and MT in the salivary gland adenocarcinoma and its stroma in order to observe the phenomenon of stromal remodeling. The tissue samples of salivary gland adenocarcinomas and their stromas and the palatine tonsils which constituted the reference group were obtained during routine surgical procedures. The immunoreactivity of vimentin, metalothionein, CD56, CD57 antigens was evaluated by the immunohistochemistry method in 30 tissue samples of parotid adenocarcinoma. The patient's consent was obtained in each case. A statistically significantly higher level of MT immunoreactivity was observed in the adenocarcinoma tissue slides than in either the stromal slides or the reference slides while no differences in MT immunoreactivity were detected when the stroma and reference tissue slides were compared. A statistically significantly higher vimentin immunoreactivity level was identified in the tumor microenvironment tissue slides than in the tumor tissue slides, and a statistically significantly higher level of vimentin immunoreactivity was identified in the tumor microenvironment slides than in the slides of the reference tissue, while no differences were identified between the adenocarcinoma tissue slides and the reference slides with respect to vimentin immunoreactivity. A statistically significantly higher number of CD56- and CD57-expressing cells were identified in the reference tissue slides than in either the adenocarcinoma or stromal slides. In conclusion, the stroma of salivary gland adenocarcinoma in this study has been characterized by remodeling. The remodeling is represented by the expression of both vimentin and MT and by a deficit of CD57- and CD58-expressing cell infiltration. This situation would seem to be the result of immune tolerance for the tumor developing within the tumor microenvironment. Furthermore, the presence of MT and vimentin immunoreactivity in the fibroblasts of the tumor stroma may constitute a marker of active tissue remodeling.

Cancer-associated fibroblasts, a parameter of the tumor microenvironment, overcomes carcinoma-associated parameters in the prognosis of patients with mobile tongue cancer

Mobile tongue squamous cell carcinoma (MTSCC) is known for its strong propensity for regional metastasis and poor patient survival despite aggressive treatment, thus calling for new and reliable markers for predicting prognosis and guiding therapeutic management. Towards this end, three classes of markers were investigated: cancer-associated fibroblasts (CAFs; α-SMA positivity) as a representative of the tumor microenvironment, maspin (mammary serine protease inhibitor) as a tumor marker likely to be modulated by factors within the tumor microenvironment, and DNA content and Ki-67 labeling index as inbuilt tumor markers in 128 cases of MTSCC using immunohistochemistry and image cytometry. Of these markers, only CAF density was independently and relatively strongly associated with elevated mortality from MTSCC. The hazard ratio in the CAF-rich type of tumor microenvironment was 4.85 (95% CI 1.41-16.6, versus the CAF-poor) when adjusted by proportional hazards modeling for the center where the patient was managed, gender, tumor stage, presence of neck metastasis and age at diagnosis. CAF density was unrelated to non-MTSSC mortality. Given the strong association between increased CAF density and higher mortality in MTSCC, routine assessment of CAF density for disease course prognosis and inclusion as an integral part of treatment protocols are recommended.

Cancer-associated fibroblasts and epithelial-mesenchymal transition in metastatic oral tongue squamous cell carcinoma

We examined cancer-associated fibroblasts (CAFs) and a panel of immunohistochemical markers of epithelial-mesenchymal transition (EMT) in 19 pair-matched oral tongue squamous cell carcinoma (SCC) and metastatic tumors to regional lymph nodes (RLNs). alpha-Smooth muscle actin (alpha-SMA) was studied to identify CAFs. EMT was studied with syndecan-1, Cadherin-11, fibroblast-specific protein (FSP)-1, secreted protein acidic and rich in cysteine (SPARC) and Twist. Triple immunostaining in RLNs was used to highlight the carcinoma cells (E-cadherin and Ki-67) and their relationship to the CAFs (alpha-SMA). We found that metastatic RLNs hosted CAFs similarly as in pair-matched primary tumors. Expression of EMT markers is common in both primary and metastatic tumors. We demonstrate that metastatic carcinoma cells (Ki-67 positive) downregulate E-cadherin expression at the periphery of cancer islands, where they are in direct contact with CAFs. The supporting connective tissue microenvironment also commonly expresses syndecan-1, Cadherin-11, FSP-1, and SPARC. In conclusion, CAFs are common to both primary and metastatic SCC. We hypothesize that CAFs not only promote tumor invasion but also facilitate metastases, either by cometastasizing and/or being recruited to lymph nodes. Evidence of EMT is common within primary tumors and metastatic SCC and may be further modulated by CAFs.

Tumor-host histopathologic variables, stromal myofibroblasts and risk score, are significantly associated with recurrent disease in tongue cancer

Margin status, a major prognostic parameter in oral cancer, was analyzed vis-à-vis the histopathologic parameters of risk scores and stromal myofibroblasts. Specimens of tongue carcinoma (n = 50) were submitted to a risk score assignment consisting of the worst pattern of invasion, lymphocytic infiltration, and perineural invasion. Frequency of stromal myofibroblasts (alpha-smooth muscle actin stain) was assessed. A triple immunostaining assay with E-cadherin, Ki-67 and alpha-smooth muscle actin was used to identify carcinoma cells undergoing epithelial-mesenchymal transition. Margins were considered 'clean' if the tumor was >or=5 mm away from them. Patients Collapse

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MESH Headings

• Adult
• Aged
• Aged, 80 and over
• Cadherins/analysis
• Epithelium/pathology
• Female
• Fibroblasts/pathology
• Humans
• Male
• Mesoderm/pathology
• Middle Aged
• Neoplasm Recurrence, Local/pathology
• Risk
• Stromal Cells/pathology
• Tongue Neoplasms/etiology
• Tongue Neoplasms/pathology

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Affiliation(s)

Marilena Vered Institute of Pathology, The Chaim Sheba Medical Center, Tel Hashomer, Israel.
Alex Dobriyan
Dan Dayan
Ran Yahalom
Yoav P Talmi
Lev Bedrin
Iris Barshack
Shlomo Taicher

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