Molecular markers in the surgical margin of oral carcinomas

Surgical margins in head and neck squamous cell carcinoma: A narrative review

Head and neck squamous cell carcinoma (HNSCC), a prevalent and frequently recurring malignancy, often necessitates surgical intervention. The surgical margin (SM) plays a pivotal role in determining the postoperative treatment strategy and prognostic evaluation of HNSCC. Nonetheless, the process of clinical appraisal and assessment of the SMs remains a complex and indeterminate endeavor, thereby leading to potential difficulties for surgeons in defining the extent of resection. In this regard, we undertake a comprehensive review of the suggested surgical distance in varying circumstances, diverse methods of margin evaluation, and the delicate balance that must be maintained between tissue resection and preservation in head and neck surgical procedures. This review is intended to provide surgeons with pragmatic guidance in selecting the most suitable resection techniques, and in improving patients' quality of life by achieving optimal functional and aesthetic restoration.

Therapy-induced senescence as a component of tumor biology: Evidence from clinical cancer

Therapy-Induced Senescence (TIS) is an established response to anticancer therapy in a variety of cancer models. Ample evidence has characterized the triggers, hallmarks, and functional outcomes of TIS in preclinical studies; however, limited evidence delineates TIS in clinical cancer (human tumor samples). We examined the literature that investigated the induction of TIS in samples derived from human cancers and highlighted the major findings that suggested that TIS represents a main constituent of tumor biology. The most frequently utilized approach to identify TIS in human cancers was to investigate the protein expression of senescence-associated markers (such as cyclins, cyclin-dependent kinase inhibitors, Ki67, DNA damage repair response markers, DEC1, and DcR1) via immunohistochemical techniques using formalin-fixed paraffin-embedded (FFPE) tissue samples and/or testing the upregulation of Senescence-Associated β-galactosidase (SA-β-gal) in frozen sections of unfixed tumor samples. Collectively, and in studies where the extent of TIS was determined, TIS was detected in 31-66% of tumors exposed to various forms of chemotherapy. Moreover, TIS was not only limited to both malignant and non-malignant components of tumoral tissue but was also identified in samples of normal (non-transformed) tissue upon chemo- or radiotherapy exposure. Nevertheless, the available evidence continues to be limited and requires a more rigorous assessment of in vivo senescence based on novel approaches and more reliable molecular signatures. The accurate assessment of TIS will be beneficial for determining its relevant contribution to the overall outcome of cancer therapy and the potential translatability of senotherapeutics.

Somatic genomic imbalances in 'tumour-free' surgical margins of oral cancer

Up to 30% of oral squamous cell carcinoma (OSCC) patients develop local recurrence and distant metastasis. The molecular status of histologically cancer-free tumour margins could be a critical factor in predicting tumour behaviour. The aim of this study was to detect somatic genomic imbalances in OSCC with emphasis on the surgical margins. DNA was isolated from tumour tissues, margin tissues, and blood samples (used as control) obtained from 11 OSCC patients, and genome-wide array comparative genomic hybridization was performed. Imbalances were present in both tumours and margins, although, as expected, they were more prevalent in tumours (duplications, P = 0.0002; deletions, P = 0.0001). Duplications were more frequent than deletions in both tumours and margins, but without statistical significance. Fifteen imbalances in tumour tissues were recurrent and all of them were duplications. Four of these were found both in tumours and margins and involved chromosomes 1q, 8p, Xp, Yp, and Yq. Four imbalances were recurrent in margin tissue and all of them were duplications (autosomes 8 and 17 and both sex chromosomes). Histologically 'cancer-free' margins hide genomic alterations consistent with unexplained OSCC recurrences. Establishing the molecular status of the margins could improve outcome prediction.

Assessing immuno-expression of p53 protein and TP 53 gene amplification in histologically negative surgical margins of oral squamous cell carcinoma patients and normal oral mucosa

OBJECTIVE

To assess and compare the immuno-expression of p53 and TP 53 gene amplification and correlate local recurrence and survival in histologically negative surgical margins of oral squamous cell carcinoma (OSCC) with normal oral mucosa.

METHODS

Forty formalin-fixed paraffin-embedded tissue blocks of HNMs of OSCC and 40 normal oral mucosa samples were analyzed for p53 immunostaining and TP 53 gene amplification by PCR.

RESULTS

Significantly, higher positivity was noted with p53 immuno-expression, TP53 gene amplification, and combined p53 and TP53 expression in the study group compared to the control group (C0.05). Most cases that were positive for p53 immuno-expression, TP 53 gene amplification, and combined p53 and TP53 expression showed local recurrence and poor survival. Kaplan-Meier survival analysis showed that subjects with TP53 and combined p53 and TP53 positivity had decreased survival rate than their negative counterparts.

CONCLUSION

Detection of p53 in HNMs of OSCC can be used as a biomarker to identify patients at a higher risk of developing local recurrence and to predict survival.

CLINICAL RELEVANCE

Combined p53 and TP 53 assessment may be more reliable for predicting LR to help clinicians and surgeons in treatment planning.

Risk Factors of Microscopically Tumor-Free Surgical Margins for Recurrence and Survival of Oral Squamous Cell Carcinoma Patients

Objectives

The concept of adequate surgical margins remains controversial in oral squamous cell carcinoma (OSCC) surgery. This study aimed to identify surgical margin-related indicators that might impact recurrence and survival of OSCC patients.

Materials and Methods

Histopathological examination was performed using hematoxylin-eosin-stained surgical margin tissue sections in 235 OSCC patients. Axin2 and Snail expression at the surgical margin was detected by immunohistochemistry. The impact of the Axin2-Snail cascade on tumorigenesis of the immortalized human oral keratinocyte (IHOK) line was investigated in vivo.

Results

The width and dysplasia of surgical margins were not significantly associated with the outcome of OSCC patients. In a multivariate analysis using variable clinicopathologic factors and with Axin2 and Snail expression as cofactors, higher age (hazard ratio [HR]:1.050; P=0.047), Axin2 (HR:6.883; P=0.014), and Snail abundance (HR:5.663; P=0.009) had independent impacts on worsened overall survival. Similarly, lesion site in retromolar trigone (HR:4.077; P=0.010), upper (HR:4.332; P=0.005) and lower gingiva (HR:3.545; P=0.012), presence of extranodal extension (HR:9.967; P<0.001), perineural invasion (HR:3.627; P=0.024), and Snail abundance (HR:3.587; P<0.001) had independent impacts on worsened recurrence-free survival. Furthermore, Axin2 knockdown induced decreased Snail expression and attenuated tumorigenesis in the IHOK line.

Conclusion

Histopathological examination of surgical margins may not be reliable to predict OSCC patient outcome. Molecular analysis may provide a more accurate risk assessment of surgical margins in OSCC. In particular, Axin2 and Snail are potential predictive biomarkers for the risk assessment of surgical margins in OSCC.

Outcomes of Recurrent Nasopharyngeal Carcinoma Patients Treated With Salvage Surgery: A Meta-Analysis

Objective

To assess the efficacy of treatment outcomes of salvage surgery for recurrent nasopharyngeal carcinoma (rNPC).

Methods

We conducted a detailed search of the literatures in biomedical databases published from January 1990 to December 2020. The main research features and results of interest were retrieved from the articles that met the selection criteria for meta-analysis.

Results

A total of 21 articles with 778 patients were included, 17 of which met the meta-analysis inclusion criteria. The pooled 2-year overall survival (OS), 5-year OS, and 2-year disease-free survival (DFS) were 71%, 50% and 61%, respectively. Subgroup analysis was conducted with postoperative adjuvant therapy. The pooled 2-year OS, 5-year OS and 2-year DFS of the postoperative adjuvant therapy group compared with the surgery alone group were 69% vs 72%, 44% vs 56%, and 77% vs 54%, respectively. Univariate and multivariate analyses were performed on 178 patients with detailed individual postoperative survival data in 10 articles. On multivariate analysis, recurrent T (RT) stage and adjuvant therapy were independent predictors of outcomes.

Conclusions

This meta-analysis indicated that recurrent NPC patients can obtain survival benefits from salvage surgery. Accurately assessing the RT stage of the tumor and choosing the appropriate surgical method are important to the success of the surgery. Although the prognostic factors influencing outcome have been studied, conclusive data on the survival benefits are still lacking. Random controlled trials (RCTs) to compare surgery alone and postoperative adjuvant therapy are needed in patients with positive margin status after salvage surgery.

Immunoexpression of p53 in histologically negative surgical margins adjacent to oral squamous cell carcinoma: A preliminary study

The prognostic significance of genetic changes occurring in the histologically negative surgical margins (HNMs) has been focus of various studies recently. Since p53 is the most frequently observed genetic alteration found in oral squamous cell carcinoma (OSCC), we hypothesized that a similar variation might be evident in HNMs as well. Literature is scarce regarding comparison of expression of p53 in the tumor tissue and its adjacent HNMs; hence, the aim of the present study was to study p53 immunoexpression in OSCC and its HNMs. We included 12 paraffin-embedded tissue blocks of OSCC having tumor tissue and HNMs. The samples were subjected to immunohistochemical staining using primary mouse monoclonal antibody against p53, and the stained slides were evaluated for staining intensity and percentage of expression. Descriptive analysis and Chi-square test were applied. The expression of p53 was observed in 66% of HNMs and 91.6% of tumor tissue. The three cases which showed local recurrence demonstrated the expression of p53 in HNM. Hence, molecular analysis of p53 in surgical margins might potentially predict local recurrence of OSCC.

A 4-gene signature from histologically normal surgical margins predicts local recurrence in patients with oral carcinoma: clinical validation

Prognostic biomarkers for recurrence of Oral Squamous Cell Carcinoma (OSCC) are urgently needed. We aimed to independently validate a 4-gene expression signature (MMP1, COL4A1, P4HA2, THBS2) predictive of OSCC recurrence risk. Gene expression was measured using Nanostring nCounter^® in 245 histologically normal surgical resection margins from 62 patients. Association between risk scores for individual patients and recurrence was assessed by Kaplan-Meier analysis. Signature performance was quantified by concordance index (CI), hazard ratio (HR) and the area under receiver operating characteristics (AUC). Risk scores for recurrence were significantly higher than recurrence-free patients (p = 9.58e-7, Welch’s t-test). A solid performance of the 4-gene signature was determined: CI = 0.64, HR = 3.38 (p = 1.4E-4; log-rank test), AUC = 0.71. We showed that three margins per patient are sufficient to preserve predictive performance (CI = 0.65; HR = 2.92; p = 2.94e-3; AUC = 0.71). Association between the predicted risk scores and recurrence was assessed and showed HR = 2.44 (p = 9.6E-3; log-rank test, N = 62). Signature performance analysis was repeated using an optimized threshold (70^th percentile of risks), resulting in HR = 3.38 (p = 1.4E-4; log-rank test, N = 62). The 4-gene signature was validated as predictive of recurrence risk in an independent cohort of patients with resected OSCC and histologically negative margins, and is potentially applicable for clinical decision making on adjuvant treatment and disease monitoring.

Comparative Evaluation of Immunohistochemical Expression of p16 with p16 Microsatellite Marker by PCR in Surgical Margins of Oral Squamous Cell Carcinoma

Oral squamous cell carcinoma (OSCC) is most common oral cancer with multifactorial etiology. Surgical therapy is treatment of choice but known to have recurrence. The main reason for recurrence is associated with surgical margins which need to be tumor free. Changes at genetic level cannot be ascertained only through routine light microscopy in surgical margins, even though they are tumor free. Detection of early marker like p16 can help in predicting the risk of recurrence. Hence study aimed to detect p16 microsatellite marker (D9s1747) in surgical margins of oral squamous cell carcinoma and compare the same with p16 marker through immunohistochemistry. Total of 40 paraffin embedded tissue samples diagnosed and surgically treated cases of OSCC were included. From each sample one tumor proper and one surgical margin was obtained. From paraffin embedded tissue sample 2 sections of 4 µm thick was obtained from tumor proper and tumor margin. One section was stained with hematoxylin and eosin and other section was stained immunohistochemically using p16 antibody. DNA extraction was done for tumor proper and surgical margin tissue and PCR analysis was carried for p16 microsatellite marker (D91747). Out of 40 cases 37 cases showed positivity in tumor proper for p16 with IHC. Out of 37 cases 23 cases showed positivity for both tumor proper and surgical margin. There were 3 cases negative for tumor proper. Out of these 3 cases, 1 (33.3%) case was positive for surgical margin. Out of 40 cases 27 cases showed positivity for tumor proper with p16 microsatellite marker. Out of 27 cases 16 cases showed positivity for both tumor proper and surgical margin. There were 13 cases negative for tumor proper. However there were 8 (61.5%) cases negative which were in tumor proper but showed positivity for surgical margin. Other 5 cases were negative in both tumor proper and surgical margin. Our study reveals that surgical margins of OSCC exhibit alteration in p16 markers both by IHC and PCR techniques. p16 and p16 microsatellite marker detection in margins indicates field change. Further studies with larger sample size comparing expression with clinical and histological parameter and follow up has to be done to substantiate our findings.

Molecular Analysis as a Guide to Determining the Extent and Pathophysiology of Perilesional Tissues in Oral Epithelial Dysplasias

Introduction

Clinically and histologically normal appearing perilesional mucosa of epithelial dysplasia may harbor early genetic changes. Hence, the present study is designed to determine the early molecular changes in the form of p16 and EGFR immunoexpressions in perilesional tissues.

Objectives

To analyze immunohistochemical expressions of p16 and EGFR individually and percentage change of immunoexpressions in oral dysplastic lesions and their perilesional tissues.

Materials and Methods

Forty formalin-fixed paraffin-embedded tissues of oral epithelial dysplasia with perilesional tissue marked by India ink were included in this study. Immunohistochemical staining was performed using anti-p16 and anti-EGFR monoclonal antibodies (BioGenex) using squamous cell carcinoma of uterine cervix and breast carcinoma as the positive controls, respectively.

Results

p16 and EGFR expressions were assessed based on the presence, intensity, extent and immunolocalization of positive cells. Out of 40 cases, p16 immunoexpression was positive in 82.5% cases of lesional tissues and in 62.5% cases of perilesional tissues (p ≤ 0.05); however, EGFR immunoexpression was positive in 90% cases of both lesional and perilesional tissues (p > 0.05).

Conclusion

The disease status and progression based on p16 and EGFR expressions and co-expressions can be used as an effective guide to evaluating the progression of normal epithelium to dysplastic epithelium in otherwise clinically normal mucosa.

Genetic and epigenetic alterations in the tumour, tumour margins, and normal buccal mucosa of patients with oral cancer

Despite adequate surgical resection, oral squamous cell carcinoma (OSCC) shows a high rate of recurrence and metastasis, which could be explained by the presence of molecular alterations in seemingly normal tumour margins and the entire oral mucosa. The aims of this study were (1) to assess the presence of gene amplification (c-Myc and HER2) and promoter methylation (p14 and p16) in the tumours, tumour margins, and unaffected oral mucosa of 40 OSCC patients, and (2) to evaluate the possibility of using these alterations as prognostic markers. c-Myc and HER2 genes were quantified by means of real-time PCR (qPCR), and p14 and p16 methylation status was determined by methylation-specific PCR (MSP PCR). All tissues examined exhibited molecular alterations in various proportions. Tumour tissues, as expected, showed the highest prevalence of alterations, while oral mucosa showed the lowest. Multiple alterations (co-alterations) in tumours and tumour margins were significantly more frequent than in unaffected oral mucosa (P<0.001 and P=0.027, respectively). HER2 amplification in margin tissue (P<0.001) and swabs (P=0.013), as well as the existence of three co-alterations in margins (P=0.001) and macroscopically unaffected oral mucosa (P<0.001) were correlated with shorter disease-specific survival.

Inflammation related genes are upregulated in surgical margins of advanced stage oral squamous cell carcinoma

Aims

Advanced stage of oral squamous cell carcinoma (OSCC) exhibits different properties compared with the early stage for example an invasion ability. The present study investigated a differential gene expression of surgical margin between advanced and early stage of OSCC.

Methods

Gene Expression Omnibus dataset (GSE31056) was downloaded and re-analyzed. Surgical margin samples were categorized into 2 groups; early stage and late stage. Differential gene expression analysis was performed. Dysregulated genes were further analyzed for gene ontology, enriched pathway, and disease association using a network-based analysis tools.

Results

Eighty-five dysregulated genes were identified in margin of late stage OSCC. Metabolic process and biological regulation were the main gene ontology of dysregulated genes. Genes involved in Jak-STAT signaling pathway were upregulated in late stage of surgical margin samples. In addition, seven upregulated genes in late stage group, namely CEBPB, S1PR1, IL6, CEBPD, CHI3L1, PTX3, and SOCS3, were categorized in acute phase reaction and inflammation categories of disease association analysis.

Conclusion

The differential expressed genes in surgical margin of late stage OSCC could be further employed to understand cancer's behavior and to identify target pathway to prevent OSCC invasion.

Expression of Osteopontin in Oral Squamous Cell Carcinoma and its Surgical Margins-An Immunohistochemical Study

INTRODUCTION

Despite the advances in the treatment modalities offered for oral squamous cell carcinoma. The recurrence rate of it still remains quite high. Early detection of recurrence will improve the outcome and the survival of the patient. Osteopontin, a transformation-related phosphorylated protein in epithelial cells has been closely related with tumourigenesis. This study was undertaken to explore the potential of OPN as a tumour marker of recurrence in OSCC.

AIM

To analyse the expression of Osteopontin (OPN) in Oral Squamous Cell Carcinoma (OSCC), patient matched tumour free surgical margins and normal oral mucosa and to correlate with local & loco regional recurrence.

MATERIALS AND METHODS

Twenty cases each of formalin fixed paraffin embedded blocks of histopathologically diagnosed cases of OSCC, patient matched tumour free surgical margins and normal oral mucosal tissues were obtained from the archives of the Oral Pathology & Microbiology Department, Faculty of Dental Sciences, SRU and Govt. Arignar Anna Memorial Cancer Hospital, Kancheepuram. Immunohistochemical analysis was performed with an antibody to Osteopontin protein. Patients with secondary tumours and those treated with chemotherapy and radiotherapy were excluded from this study.

RESULTS

The expression of OPN was elevated in 95% of tumours & 55% of histologically tumour free margin samples. There was negative OPN expression in normal mucosal samples. The result of the study was statistically analysed using Pearson chi-square test and was found to be statistically significant.

CONCLUSION

OPN can be used as a diagnostic marker in Oral Squamous Cell Carcinoma. In the tumour free surgical margins, elevated levels of OPN may predict a significantly increased risk of recurrence.

Evaluation of immunohistochemical expression of p16 and presence of human papillomavirus in oral and oropharyngeal carcinoma

Carcinogenesis concerns several changes that eventually result in the inactivation of tumor suppressor genes and activation of protooncogenes, leading to loss of cell cycle control. Inactivation of p16 seems to be an early event in this process and occurs in approximately 80% of squamous cell carcinoma cases. The aims of this study were to evaluate the immunohistochemical expression of p16 protein in oral and oropharyngeal squamous cell carcinoma cases, with both the tumoral area itself and its surgical margin being analyzed (dysplastic areas and histologically normal epithelium adjacent to carcinoma), and to verify the presence of human papillomavirus (HPV) and its relation to p16 expression. Paraffin-embedded biopsy tissues from 26 patients, 13 with oral squamous cell carcinoma and 13 with oropharyngeal squamous cell carcinoma, comprised the analyzed samples. To detect HPV, a nested polymerase chain reaction test using PGMY 09/11 and GP5*/GP6* primers and visualization of the product on a 2% agarose gel was performed. Demographic data were obtained from medical records. The results showed low expression of p16 in the tumor area (38.46%), compared with surgical margins in the histologically normal epithelium (84.6%) and dysplastic areas (57.7%). These findings indicate the inactivation of p16 in the process of malignant transformation. The association described in the literature between expression of p16 and presence of HPV could not be verified in this study, because none of the cases was HPV positive.

Impact of resection margin status on outcome after salvage nasopharyngectomy for recurrent nasopharyngeal carcinoma

BACKGROUND

The purpose of this study was to present the postoperative local tumor control and survival with regard to the different resection margin statuses during salvage nasopharyngectomy.

METHODS

We conducted a whole-organ study of nasopharyngectomy specimens.

RESULTS

Between 2005 and 2010, 126 patients underwent maxillary swing nasopharyngectomy. The T classification of the recurrent tumor was: T1, 23.8%; T2, 41.3%; T3, 28.6%; and T4, 6.3%. The chance of clear, close, and involved resection margins at nasopharyngectomy was 44.4%, 31.0%, and 24.6%, respectively. At follow-up, the corresponding risk of local tumor recurrence after surgery was 10.7%, 38.5%, and 67.7%, respectively. The local tumor control was significantly worse in patients with involved margins compared with those with close margins (p = .01), which was, in turn, significantly worse than those with clear margins (p = .04).

CONCLUSION

The primary objective of salvage nasopharyngectomy is to achieve clear resection margins. Close and involved margins result in significantly inferior local tumor control and overall survival. © 2015 Wiley Periodicals, Inc. Head Neck 38: E594-E599, 2016.

The role of Epstein-Barr virus-encoded microRNA BART7 status of resection margins in the prediction of local recurrence after salvage nasopharyngectomy for recurrent nasopharyngeal carcinoma

BACKGROUND

Local recurrence is the major cause of treatment failure in patients who undergo surgical salvage of recurrent nasopharyngeal carcinoma (NPC) after radiotherapy. The authors investigated the role of Epstein-Barr virus (EBV)-encoded Bam HI-A rightward transcript 7 microRNA (BART7) status in resection margins in the identification of a subgroup of patients who may benefit from adjuvant reradiation after surgery.

METHODS

One hundred two consecutive patients who had histologically clear resection margins after undergoing nasopharyngectomy for recurrent NPC were studied. The status of EBV microRNA BART7 in resection margins was investigated and correlated with the pattern of subsequent disease recurrence.

RESULTS

After a median follow-up of 64 months, 20 patients (19.6%) developed local recurrence after surgery despite histologically uninvolved margins. The risk of local recurrence in patients with histologically close (<5 mm) and clear (≥5 mm) margins was 31.6% and 12.5%, respectively. In patients with clear histologic margins, those with margins that were positive for EBV microRNA BART7 has a significantly higher chance of developing local tumor recurrence (P = .016) than those with negative molecular margins. The difference was not significant when the histologic clearance at the resection margins was <5 mm.

CONCLUSIONS

Tissue EBV microRNA BART7 is useful for identifying a subgroup of patients with histologically clear margins who are at increased risk of subsequent local tumor recurrence. Postoperative adjuvant treatment is warranted for these patients.

Single cell migration in oral squamous cell carcinoma - possible evidence of epithelial-mesenchymal transition in vivo

BACKGROUND

The invasion of cancer cells into the surrounding normal tissue is one of the defining features of cancer. While the phenomena of tumour budding, epithelial-mesenchymal transition and the presence of myofibroblasts have independently been shown to be related to a poor prognosis of oral carcinomas, their relationship has not been examined in detail.

METHODS

Paraffin-embedded tissues from 28 patients with oral squamous cell carcinomas were stained with antibodies to cytokeratin, α-SMA, vimentin, E-cadherin, N-cadherin and Twist and evaluated for their expression in relation to invasive cancer cells and the surrounding tumour stroma.

RESULTS AND CONCLUSIONS

A direct, histological relationship between invading, budding tumour cells and myofibroblasts was occasionally seen but was not a general feature. Most of the budding tumour cells at the invasive front had a decreased expression of E-cadherin, but we did not find that this was associated with a consistent or clear increase in either N-cadherin or vimentin. We therefore suggest that the budding of tumour cells is not dependent upon either myofibroblasts or a complete epithelial-mesenchymal transition and that these phenomena most likely represent separate processes in tumour progression.

Expression of the cancer stem cell markers CD44v6 and ABCG2 in tongue cancer: effect of neoadjuvant chemotherapy on local recurrence

The efficacy of neoadjuvant chemotherapy (NAC) is controversial, and no report supports NAC with a high evidence level. Recently, we showed that a deep surgical margin was resected very close to the tumor site in many NAC-treated oral squamous cell carcinoma patients, suggesting that NAC may lead to local recurrence and poor outcomes. The purpose of this study was to evaluate the effect of NAC on tumor local recurrence using cancer stem cell marker immunohistochemistry. We retrospectively analyzed 89 patients who underwent radical surgery for tongue cancer, and examined the effect of NAC on tumor local recurrence. Cancer stem cell marker (CD44v6 and ABCG2) expression was detected by immunohistochemistry. In our study, the local recurrence rate was 12.4%. CD44v6 and ABCG2 expression was significantly associated with regional lymph node metastasis, pattern of invasion, depth of invasion, perineural invasion and local recurrence, respectively. Tumor local recurrence was a significant independent predictive factor of the 5-year disease specific survival. CD44v6 or ABCG2 positivity in NAC-treated patients was significantly associated with tumor local recurrence. It was suggested that local recurrence in NAC-treated cases is associated with cancer stem-like cells. We propose that NAC leads to the selection and/or residue of more aggressive cancer stem-like cells.

Assessment of laminin-5 in oral dysplasia and squamous cell carcinoma

PURPOSE

Laminin-5 is an important protein in the establishment of an intact basement membrane. The aims of this study were to assess the expression of laminin-5 (γ2 chain) using cyclin D1 and Ki-67 in hyperplastic oral mucosal lesions, oral dysplasia, and squamous cell carcinoma (SCC).

MATERIALS AND METHODS

Paraffin-embedded tissue blocks of 134 patients were stained for laminin-5, cyclin D1, and Ki-67 using immunohistochemistry and assessed by virtual microscopy. Statistical analysis was performed using Kruskal-Wallis tests and Mann-Whitney U tests for post hoc assessment.

RESULTS

Laminin-5, cyclin D1, and Ki-67 were found to have significant differences in expression for the different categories of dysplasia, SCC, and hyperplasia (P < .001). Cyclin D1 and Ki-67 expression levels were significantly increased in moderate and severe dysplasia and SCC, with no significant difference in expression between hyperplasia and mild dysplasia or between biopsies of severe dysplasia and SCC. Laminin-5 expression was only significantly increased in SCC, confirming it as a marker of malignant transformation and invasion.

CONCLUSIONS

The results of this study indicate that overexpression of laminin-5 is found only in SCC and not dysplastic lesions. Therefore, laminin-5 has potential as a marker for the intraoperative assessment of cancer excision margins and could be used as a target for chemotherapeutic agents.

In vitro cytotoxic effects of Brazilian plant extracts on squamous cell carcinoma of the oral cavity

Squamous cell carcinoma (SCC) is the most prevalent cancer of the oral cavity and the fifth most prevalent of all malignancies in males. Many researchers have attempted to develop new treatments that will improve the prognosis of SCC patients. Over 20% of the world's biodiversity is located within the Brazilian forests, but little is known about the chemical and/or pharmacological potential of these plants. Certain extracts obtained from Amazon and Atlantic Forest plants have previously been shown to have cytotoxic activity against various cancers. The aim of this study was to screen these extracts for cytotoxic activity against oral SCC cells. The extracts were analyzed for activity against the KB-ADL#12 cell line at various concentrations up to a maximum dose of 100 µg/mL. Comparisons with a control group were performed using one-way ANOVA. Significant cytotoxicity was induced by the extracts obtained from the aerial parts of Picrolemma sprucei (Simaroubaceae), from the leaves and stems of Laetia suaveolens (Salicaceae), from the aerial parts of Abarema auriculata (Fabaceae-Mimosoideae) and from the stem of A. auriculata.

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

Background

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

Methods

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

Results

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

Conclusion

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

p16(INK4a)/CDKN2 expression and its relationship with oral squamous cell carcinoma is our current knowledge enough?

Oral squamous cell carcinomas (OSCC) are the most common malignancy of the oral cavity and their multistep development requires the accumulation of multiple genetic and epigenetic alterations. Inactivation of p16(INK4a), encoded by the CDKN2 gene has been widely associated with this type of tumors. The purpose of this review is to elucidate the relationship between p16(INK4a) expression and the different clinical and pathological aspects of OSCC, analyze the variation in results between studies, detailing the described genetic/epigenetic alterations that result in gene silencing and the relationship between p16(INK4a) and HPV infection.

Association between expression of embryonic lethal abnormal vision-like protein HuR and cyclooxygenase-2 in oral squamous cell carcinoma

BACKGROUND

Increased cytoplasmic HuR expression has been noted in several cancer types, where it may contribute to the increased cyclooxygenase-2 (COX-2) expression observed during tumorigenesis and metastasis.

METHODS

To assess the correlation between COX-2 and HuR in oral squamous cell carcinoma (OSCC), the expression patterns of HuR and COX-2 were assessed via immunohistochemistry analyses of 103 OSCC samples.

RESULTS

Cytoplasmic HuR expression was significantly associated with COX-2 expression (p < .025) and lymph node metastasis (p < .050) and distant metastasis (p < .025). In multivariate analysis, cytoplasmic HuR expression was identified as an independent prognostic parameter for reduced overall survival. The inhibition of HuR expression by siRNA or leptomycin B (LMB) caused a reduction in the inducibility of COX-2 in oral cancer cells.

CONCLUSION

Our results indicate that the cytoplasmic expression of HuR is associated with COX-2 expression in OSCCs and HuR can regulate COX-2 expression in oral cancer cell lines.

Basement membrane components are key players in specialized extracellular matrices

More than three decades ago, basement membranes (BMs) were described as membrane-like structures capable of isolating a cell from and connecting a cell to its environment. Since this time, it has been revealed that BMs are specialized extracellular matrices (sECMs) with unique components that support important functions including differentiation, proliferation, migration, and chemotaxis of cells during development. The composition of these sECM is as unique as the tissues to which they are localized, opening the possibility that such matrices can fulfill distinct functions. Changes in BM composition play significant roles in facilitating the development of various diseases. Furthermore, tissues have to provide sECM for their stem cells during development and for their adult life. Here, we briefly review the latest research on these unique sECM and their components with a special emphasis on embryonic and adult stem cells and their niches.

Overview of cancer for the healthcare team: aetiopathogenesis and early diagnosis

Much cancer presents late, at a stage when not only is more radical treatment necessary, but the prognosis is also less favourable. This paper attempts to provide an overview of the aetiopathogenesis of cancer (carcinoma) for the healthcare team, a broad understanding of which is crucial for coping with issues related to prevention, diagnosis and management. Prevention of cancer involves lifestyle decisions which afford protection not only against cancers in many sites, but also against a wide range of other conditions, many of which are equally life-threatening. The paper also highlights areas of controversy in the early diagnosis of oral cancer. Earlier diagnosis is likely to be achieved reliably only with the introduction of molecular studies.

Molecular analysis of surgical margins in head and neck cancer: more than a marginal issue

The relatively modest survival of patients surgically treated for advanced HNSCC can partly be explained by the development of local relapse. It is important that surgeons are able to predict which patients are at high risk to develop local relapse, since clinical management can be tailored. Local relapse after resection of a primary HNSCC is easily explained, when tumour is detected in the surgical margins and thus residual tumour is likely to remain in the patient, but the pathobiology is more complex in cases where the margins are histologically tumour-free. Molecular studies indicate that there are two different mechanisms responsible in these cases. First, small clusters of residual tumour cells that are undetectable on routine histopathological examination (known as minimal residual cancer: MRC) proliferate and this forms the basis of recurring cancer. A second cause of relapse is a remaining field of preneoplastic cells that is struck by additional genetic hits leading to invasive cancer. It is likely that within this field, that can be over 7cm in diameter, the primary carcinoma has also emerged. Despite careful histopathological examination of the surgical margins of the primary carcinoma, it is at present not reliably possible to predict which patient will develop local relapse. Herein we focus on new developments regarding the analysis of margins, causes of local relapse, and how novel molecular techniques can be of help in a more accurate risk assessment. Critical analysis of the studies that have been published thus far shows that there is a list of promising markers, based on protein expression (immuno-histochemistry) and nucleic acid analysis. Further studies should be focused on validation and assessment of the clinical utility of these markers. Margin analysis should reveal whether one is dealing with residual cancer cells that might be treated by post-operative radiotherapy or with preneoplastic fields that remained behind. For this latter entity, there is no intervention available at present, except for a more intensive surveillance.