Immunohistochemical analysis of cell cycle-associated proteins p16, pRb, p53, p27 and Ki-67 in oral cancer and precancer with special reference to verrucous carcinomas

Role of E2F transcription factor in Oral cancer: Recent Insight and Advancements

The family of mammalian E2F transcription factors (E2Fs) comprise of 8 members (E2F1-E2F8) classified as activators (E2F1-E2F3) and repressors (E2F4-E2F8) primarily regulating the expression of several genes related to cell proliferation, apoptosis and differentiation, mainly in a cell cycle-dependent manner. E2F activity is frequently controlled via the retinoblastoma protein (pRb), cyclins, p53 and the ubiquitin-proteasome pathway. Additionally, genetic or epigenetic changes result in the deregulation of E2F family genes expression altering S phase entry and apoptosis, an important hallmark for the onset and development of cancer. Although studies reveal E2Fs to be involved in several human malignancies, the mechanisms underlying the role of E2Fs in oral cancer lies nascent and needs further investigations. This review focuses on the role of E2Fs in oral cancer and the etiological factors regulating E2Fs activity, which in turn transcriptionally control the expression of their target genes, thus contributing to cell proliferation, metastasis, and drug/therapy resistance. Further, we will discuss therapeutic strategies for E2Fs, which may prevent oral tumor growth, metastasis, and drug resistance.

Human Papilloma Virus and Cancer Stem Cell markers in Oral Epithelial Dysplasia-An Immunohistochemical Study

OBJECTIVES

To study the correlation between the putative cancer stem cell (CSC) markers aldehyde dehydrogenase 1 (ALDH1), cluster of differentiation 44 (CD44), sex-determining region Y-box 2 (SOX2), and octamer-binding protein 4 (OCT4) and human papilloma virus (HPV) infection using p16, the surrogate marker of HPV in oral epithelial dysplasia (OED) and normal mucosa.

METHODS

Five sections each from 40 histopathologically diagnosed cases of different grades of OED and 10 cases of normal oral mucosa without dysplasia were immunohistochemically stained with p16, ALDH1, CD44, SOX2, and OCT4, respectively.

RESULTS

Expression of ALDH1 and SOX2 was significantly increased in OED cases, whereas CD44 and OCT4 expression was increased in normal mucosa. P16-positive OED cases showed upregulation of ALDH1 and OCT4 expression as compared to p16-negative cases, while CD44 and SOX2 expression was downregulated in p16-positive OED cases; however, the results were not statistically significant.

CONCLUSION

The present study indicated a suggestive link between p16 and cancer stem cell marker expression in HPV-associated OED, and that p16 has a significant role in CSC progression in OED. This is the first study to evaluate the expression of putative CSC markers in HPV-associated OED. However, low study numbers are a potential limiting factor in this study.

Advanced Verrucous Squamous Cell Carcinoma of the Esophagus: Case Report and Literature Review

Verrucous squamous cell carcinoma (VSCC) is a rare esophageal tumor histologically defined as a well-differentiated subtype. We present a rare case that was diagnosed as esophageal VSCC preoperatively. A 62-year-old Japanese man was referred to our hospital for further evaluation, presenting with anorexia and postcibal vomiting. An esophagogastroduodenoscopy examination showed esophageal stricture with white-colored papillary nodules in the lower esophagus. We performed repeated superficial endoscopic biopsies of the lesion, but the histologic findings showed nonspecific changes. With an endoscopic boring biopsy, the lesion showed an endophytic growth pattern, well-differentiated SCC with minimal cellular atypia and rare mitosis, and mature squamous epithelium with extensive keratinization. We preoperatively diagnosed the lesion as esophageal VSCC, and we performed a video-assisted thoracoscopic subtotal esophagectomy and cardiectomy with the patient in the prone position. Histologic findings revealed that the invasive well-differentiated SCC extended into the esophageal adventitia and the stomach wall with a pushing border. Regional lymph node metastasis and vascular invasion were negative. The expression of Ki-67 was distributed mainly in the basal cells rather than parabasal cells. Without a conclusive diagnosis, a certain degree of diagnostic prediction is possible by understanding the clinical manifestations, macroscopic form, and histology around the basal cells. It is helpful to obtain the high accuracy provided by an endoscopic biopsy including the basal layer to avoid the diagnostic dilemma that is often presented by esophageal VSCC.

Importance of Ki-67 Labeling in Oral Leukoplakia with Features of Dysplasia and Carcinomatous Transformation: An Observational Study over 4 Years

Background  Early detection of dysplastic changes within oral potentially malignant disorders is the mainstay to prevent oral cancer. Ki-67 is one of the most useful antigens in this purpose.

Aims  The study aims were to recognize and mutually compare the proliferative status of idiopathic oral leukoplakia (OL) patches, which presented through different forms of dysplasia and carcinoma.

Settings and Design  In 4 years of observation, cumulatively 140 OL lesions were included for examination. The wholesome Ki-67 labeling scores in each of the subgroups were calculated.

Subjects and Methods  The World Health Organization recommended histopathological classification was used to categorize the dysplastic and malignant lesions. Paraffin-embedded tissue sections were processed for Ki-67 immunostaining. The labeling indices (LIs) were quantified semiquantitatively at the site of maximal reactive cells on tissue sections.

Statistical Analysis  The statistical comparison was performed by means of the SPSS software (Version 16.0 SPSS Inc.). A p- value < 0.05 was considered as the benchmark for statistical significance.

Results  A steady and significant increment in Ki-67 expression was discovered from dysplastic to malignant OL patches compared with normal mucosa. The labeling differences were significant between normal mucosa and mild dysplasia, as well as between mild, moderate, and severe dysplasia. However, the expression did not differ significantly with the severity of oral cancers.

Conclusions  Ki-67 is a useful molecular marker of carcinogenesis in OL. It also serves worthwhile in separating marginally dysplastic lesions, such as mild dysplasia or verrucous carcinoma from their benign epigones.

Oral leukoplakia and the long-term risk of upper gastrointestinal cancer deaths in the Linxian dysplasia population

BACKGROUND

To investigate oral leukoplakia (OL) and risk of upper gastrointestinal (UGI) cancer deaths in the Linxian Dysplasia Nutrition Intervention Trial (NIT) cohort.

METHODS

A total of 3318 subjects with esophageal squamous dysplasia enrolled on 1 May 1985, and were followed up until 30 September 2015. Participants with OL at baseline were treated as an exposed group, while the remainder was selected as a control group. All subjects were followed monthly and reviewed quarterly by the Linxian Cancer Registry. Cox proportional hazard model was used to estimate hazard ratios (HRs) and 95% confidence intervals (95% CIs).

RESULTS

During the 30-year follow-up, a total of 902 UGI cancer deaths occurred, including 541 esophageal squamous cell carcinoma (ESCC) related, 284 gastric cardia carcinoma (GCC) related, and 77 gastric noncardia carcinoma (GNCC) related deaths. Relative to subjects without OL, the long-term risk of ESCC mortality in participants with OL increased by 26.1% (HR = 1.26, 95% CI: 1.05-1.52). In the subgroup analyses, adverse effects of OL on ESCC mortality were observed especially in younger subjects (HR = 1.48, 95% CI: 1.11-1.97), females (HR = 1.44, 95% CI: 1.11-1.89), non-smokers (HR = 1.44, 95% CI: 1.15-1.81), nondrinkers (HR = 1.28, 95% CI: 1.04-1.57), and individuals with a family history of cancer (HR = 1.37, 95% CI: 1.05-1.79). No associations were observed between OL and risk of GCC and GNCC mortality.

CONCLUSIONS

OL may increase the long-term risk of ESCC mortality, especially in younger subjects, females, nondrinkers, non-smokers, and subjects with a family cancer history. Future studies are needed to explore the potentially etiological mechanism.

Ki-67 Prognostic Value in Different Histological Grades of Oral Epithelial Dysplasia and Oral Squamous Cell Carcinoma

Introduction:

Abnormal cell proliferation appears to be a possible predictor of tumorigenesis, Ki-67 protein expression is closely related to the cell proliferation and could be used as a biomarker for the growth in the most of human tumors. The aim of the study: Investigating of Ki-67 expression in the pathological grades of oral epithelial dysplasia and oral squamous cell carcinomas.

Materials and Methods:

The sample consisted of 30 formalin-fixed, paraffin-embedded specimens of oral epithelial dysplasia (OED), 30 other of oral squamous cell carcinomas (OSCC), and 10 normal oral epithelium (NOE) were conventionally stained with hematoxylin and eosin and immunohistochemically stained with Ki-67 monoclonal antibody.

Results:

Expression of Ki-67 was restricted to the basal layers in the normal oral epithelium whereas Ki-67 positive cells in oral epithelial dysplasia (OED) were located in the basal, suprabasal and spinous layers, Ki-67 expression was increased in high-risk cases. Ki-67 positive cells in well-differentiated (OSCC) were located mainly in the periphery of the tumor nests, in moderately-differentiated (OSCC) were located in both peripheral and part of a center of the tumor nests whereas it was diffused in most of the Poorly-differentiated (OSCC). Statistical analysis indicated a significant difference between the expression in (OED) and (NOE), (OSCC) and (NOE), and no differences between (OED) and (OSCC).

Conclusion:

This study has concluded that Ki-67 antigen could be used as a marker for the histological grading of OED and OSCC, Expression of Ki 67 increased according to the severity of oral epithelial dysplasia.

Clinical Significance of Telomere Length and Associated Proteins in Oral Cancer

Purpose

Telomere shortening is an important event during carcinogenesis. Although studies suggest role of multiple proteins in telomere length regulation, there is dearth of reports in oral cancer which is a leading malignancy in Asian countries especially in India. Thus the present study was carried out to study these mechanisms and explore the pathways involved in telomere—telomerase regulation and identify possible prognostic markers to understand the biology of oral tumors for better treatment approaches.

Methods

Telomere length was determined by Southern Hybridisation method, telomeric repeat binding factor (TRF) 1 and 2 expression was detected by Western blot method and telomerase activation by telomeric repeat amplification protocol. Statistical analysis was done using SPSS (Version 10) software.

Results

Significant shortening of telomeres was seen in the tumor tissues as compared to normal tissues. Poor prognosis was observed in the patients with higher telomere length in malignant tissue, higher tumor to normal telomere length ratio (T/N TRF LR). Expression of TRF-2 but not TRF-1 protein was significantly higher in the malignant tissues. We also observed telomerase activation in 75 malignant tissues.

Conclusions

Our results reveal significant clinical usefulness of telomere length, T/N TRF LR and telomerase activation in the prognosis of oral cancer patients. TRF-2 overexpression in malignant tissues appears to play an important role in telomere length shortening in oral cancer.

Histologic variation in high grade oral epithelial dysplasia when associated with high-risk human papillomavirus

OBJECTIVES

Reported cytologic alterations associated with high-risk human papillomavirus (HR-HPV) in oral epithelial dysplasia (HPV-OED) need further characterization.

STUDY DESIGN

Archival cases of high-grade oral epithelial dysplasia (hgOED) (N = 38) were assigned a cytologic score (CS) based on the average number of mitotic, karyorrhectic, and apoptotic cells per high-power field. Three groups were then generated on the basis of increasing CS: Focal (group 1, N = 14), Intermediate (group 2, N = 12), and Diffuse (group 3, N = 12). Polymerase chain reaction-based HPV genotyping and p16 immunohistochemistry were performed.

RESULTS

HR-HPV was found significantly more in group 3 (83.3%) compared with groups 1 and 2 (group 1&2; 42.9% and 41.7%, respectively; P = .047). HPV16 predominated in HR-HPV-positive cases (90.5%). By location, the tongue or the floor of mouth was associated with all groups (P = .04). Increasing CS was associated with a slightly younger age (P = .04) and increased expression of p16 (P = .005). CS and p16 expression were not sensitive but were highly specific predictors for HR-HPV presence. Based on limited follow-up information, HPV-OED does not differ in clinical aggressiveness compared with conventional OED.

CONCLUSIONS

Increased CS in hgOED is strongly associated with HR-HPV (mostly HPV16) and p16 expression. CS and p16 expression are specific predictors of HR-HPV presence. Further molecular study and long-term follow-up of HPV-OED are needed.

A Randomized Double-Blind Placebo-Controlled Trial of Fruit and Vegetable Concentrates on Intermediate Biomarkers in Head and Neck Cancer

Background. Head and neck cancer (HNC) patients are at an increased risk for developing second primary tumors (SPTs). Diets rich in fruits and vegetables (FVs) may lower HNC risk. FV concentrates may offer a potential alternative to increasing FV intake. Methods. We conducted a randomized, double-blind, placebo-controlled trial to evaluate whether Juice PLUS+ (JP; a commercial product with multiple FV concentrates) has an effect on p27 and Ki-67, biomarkers associated with the risk of SPTs. During 2004-2008, we randomized 134 HNC patients to 12 weeks of JP (n = 72) or placebo (n = 62). Oral cavity mucosal biopsies and whole blood were obtained at baseline and after 12 weeks. All participants were given the opportunity to receive JP for 5 years following the end of the intervention period, and they were followed yearly for the development of SPTs. Results. After 12 weeks, patients on JP had significantly higher serum α-carotene (P = .009), β-carotene (P < .0001), and lutein (P = .003) but did not differ significantly in p27 (P = .23) or Ki-67 (P = .95). JP use following the initial 12-week trial was not significantly associated with SPT prevention. Conclusions. Despite increased serum micronutrient levels, our results do not suggest a clinical benefit of JP in HNC patients. Future studies should focus on longer intervention periods and/or modified supplement formulations with demonstrated chemopreventive properties.

Expression of Cell Cycle-associated Proteins p53, pRb, p16, p27, and Correlation With Survival: A Comparative Study on Oral Squamous Cell Carcinoma and Verrucous Carcinoma

Verrucous carcinoma (VC) is a well-differentiated form of squamous cell carcinoma (SCC) with better prognosis. Differences in molecular pathogenesis between the 2 have not been well-characterized. We conducted this study to evaluate immunohistochemical expression of cell-cycle regulatory proteins p53, pRb, p16, and p27 in SCC and VC, compare the expression in these 2 neoplasms, and assess if these markers have any diagnostic or prognostic value. Sixty cases of SCC with and without lymph node metastasis and 31 cases of VC were studied. Immunohistochemical analysis for p53, pRb, p16, and p27 was performed and the results were analyzed. SCC was most frequent in tongue (52%), whereas VC in buccal mucosa (81%). Mean age of SCC patients was significantly lower than in VC. Majority of SCCs were in stage III and IV (63%), whereas VCs were in stage I and II (84%). p53 immunopositivity was more frequent in SCC (65%) than in VC (23%) (P≤0.001). VC had lower p53 as compared with well-differentiated SCC and SCC without lymph node metastasis. No significant difference was seen in pRb, p16, and p27 expression. Disease-free survival (DFS) at 1 year for SCC was 57% whereas it was 80% for VC (P=0.02). DFS and overall survival of SCC correlated with nodal status and stage; cell-cycle-associated protein expression had no association with DFS. To conclude, p53 immunoexpression differs in SCC and VC, suggesting different pathogenesis, and it may have some utility as an adjunct to morphology to differentiate between the 2. Expression of cell-cycle-associated proteins does not influence survival in SCC.

Diagnostic Biomarkers in Oral Verrucous Carcinoma: A Systematic Review

Oral verrucous carcinoma (OVC), a low-grade variant of oral squamous cell carcinoma (OSCC), is most frequently seen in the oral cavity. No clear etiology has been found for this lesion, but human papilloma virus, chewing betel nuts, and ultraviolet radiation are suggested as probable causes. Differential diagnosis of OVC is challenging for oral pathologists. The aim of this study was to review the molecular-based approaches for differential diagnosis of OVC. An electronic search was conducted in Medline and Scopus from January 2004 to July 2015 limited to English language publications. Published papers on verrucous carcinoma (VC) were found according to the inclusion and exclusion criteria and analyzed qualitatively. Data extraction were performed according to PRISMA statement. A total of 423 articles were reviewed; out of which, 26 articles completely fulfilled the inclusion criteria. Most of the included studies investigated proliferative and apoptotic biomarkers such as p53 and Ki67. No definite conclusion was drawn for cytoskeletal biomarkers due to variability of factors and lack of significant expression. However, it seems that cytokeratin10 (CK 10) can be useful for differentiation of OVC and benign squamous lesions. Among cell surface and extracellular matrix biomarkers tissue biomarkers, matrix metalloproteinase (MMP)-2, -9, CD31 and CD68 seem to be useful for differentiation of OVC and OSCC and glucose transporter-1 (GLUT-1) can help in differentiation of OVC from oral epithelial dysplasia. Differences among OVC, OSCC and normal epithelium in expression profiles of the investigated biomarkers help in their differential diagnosis; although, clinicohistopathological similarities among verrucous hyperplasia, noninvasive OVC and invasive well-differentiated OSCC make the diagnosis difficult. Further studies are required to better differentiate these oral lesions.

p53 as a prognostic marker associated with the risk of mortality for oral squamous cell carcinoma

Oral squamous cell carcinoma (OSCC) is often associated with a poor prognosis. The purpose of the present study was to investigate survival and the risk of mortality in OSCC with regard to stage, tumor site and p53 expression. A retrospective study was performed on 150 non-consecutive cases of OSCC that were observed between January 1992 and January 2012, and were selected from a total of 580 patients according to the criteria of the homogeneity of histopathological grading (G2). The medical records were reviewed for 48 cases with disease at stage I [37 males, age 64.7±5.7 years (mean age±standard deviation); 11 females, age 70.0±3.37 years]; 27 cases with stage II (15 males, age 64.5±5.6 years; 12 females, age 69.2±3.9 years); 58 cases with stage IVa (42 males, age 66.9±5.3 years; 16 females, age 64.2±6.5 years); and 17 cases with stage IVb (16 males, age 65.7±5.4 years; 1 female, age 69 years). Monoclonal p53 antibody (clone DO-7) was used to perform the p53 immunohistochemical study. A significant association was found between the site of the tumor and p53 overexpression (P<0.0001). Stage I-II cases showed a higher cumulative probability of a 24-month survival time than stage IVa-IVb cases (P<0.0001). Cheek, floor and soft palate tumors showed a worse prognosis (P<0.0001) and tumors with p53 overexpression >50% showed a poor survival rate (P<0.0001) compared with tumors of the attached gingiva, tongue and retromolar trigone. The findings allowed the quantification of the risk mortality from OSSC with regard to stage, tumor site and the p53 expression pattern of the tumor. Data supported the absolute indications for wide surgical margins (radical surgery) in cases of T1-T2 N0 tumors of the tongue, floor, retromolar trigone and attached gingiva when p53 overexpression is >50% in association with a higher risk of mortality compared with when p53 overexpression is <50%.

Oral verrucous carcinoma: From multifactorial etiology to diverse treatment regimens (Review)

Oral verrucous carcinoma (OVC) is a verrucous variant of oral squamous cell carcinoma (OSCC), which accounts for 2-12% of all oral carcinomas with a 5-year survival rate of only approximately 50%. Enormous effort has been dedicated to this cancer, and the past decades have witnessed significant advances in relevant diagnostic and therapeutic approaches. Currently, there exist three challenges from primary sub-fields of research and clinical practice of the cancer, namely multifactorial etiology, complex molecular mechanism, and deficient treatment. This study reviews the existing literature on the cancer, encompassing its etiology, clinical manifestations and pathology, molecular mechanism, diagnosis and differential diagnosis, and treatment. For improved treatment of OVC, multifactorial etiology analysis, incorporation of effective biomarkers for mechanism illustration, and integration of multidisciplinary modalities are expounded, in an attempt to resolve the challenges and to provide a useful guide for future research in the field.

p27Kip1 expression as a prognostic marker for squamous cell carcinoma of the head and neck

Regulation of the cell cycle is essential for carcinogenesis. The cell cycle is controlled by cyclin-dependent kinases (CDKs), which are upregulated by cyclins and downregulated by CDK inhibitors (CDKIs). Decreased p27^Kip1 expression has been associated with survival rate, tumor size, histological differentiation and the presence of lymph node metastasis in patients with various types of cancer. The aim of the current study is to provide a literature review on the association between p27^Kip1 expression and the clinical and pathological aspects of head and neck squamous cell carcinoma (HNSCC), and the expression of other CDKIs of the Cip/Kip family and cyclins. Throughout the literature, different methodologies were used to determine the immunohistochemical expression of p27^Kip1; thus, results concerning p27^Kip1 expression in HNSCC vary widely. However, it has now been confirmed that p27^Kip1 is underexpressed in SCC cells. p27 may be a promising marker for determining the prognosis of HNSCC, despite the marked variability of the results obtained. An association between p27 expression and survival rate, time to recurrence and tumor stage has been observed. Based on the information currently available, it is premature to recommend the analysis of p27^Kip1 expression in guiding HNSCC treatment planning. However, although relatively unstudied, the correlation between p27^Kip1 expression and other tumor suppressor genes may turn out to be important in determining the prognosis of HNSCC. Further prospective studies utilizing standardized laboratory methodologies and statistics that facilitate meta-analyses are required to confirm this proposal.

Increased nuclear β-catenin expression in oral potentially malignant lesions: A marker of epithelial dysplasia

Background

Deregulation of ?-catenin is associated with malignant transformation; however, its relationship with potentially malignant and malignant oral processes is not fully understood. The aim of this study was to determine and compare the nuclear ?-catenin expression in oral dysplasia and oral squamous cell carcinoma (OSCC).

Material and Methods

Cross sectional study. Immunodetection of ?-catenin was performed on 72 samples, with the following distribution: 21 mild dysplasia, 12 moderate dysplasia, severe dysplasia 3, 36 OSCC including 19 well differentiated, 15 moderately differentiated and 2 poorly differentiated. Through microscopic observation the number of positive cells per 1000 epithelial cells was counted. For the statistical analysis, the Kruskal Wallis test was used.

Results

Nuclear expression of ?-catenin was observed in all samples with severe and moderate dysplasia, with a median of 267.5, in comparison to mild dysplasia whose median was 103.75. Only 10 samples (27.7%) with OSCC showed nuclear expression, with statistically significant differences between groups (p < 0.05).

Conclusions

Our results are consistent with most of the reports which show increased presence of ?-catenin in severe and moderate dysplasia compared to mild dysplasia; however the expression of nuclear ?-catenin decreased after starting the invasive neoplastic process. This suggests a role for this protein in the progression of dysplasia and early malignant transformation to OSCC. Immunodetection of ?-catenin could be a possible immune marker in the detection of oral dysplasia.

Key words:Oral squamous cell carcinoma (OSCC), ?-catenin, oral dysplasia.

Reliability of Incision Biopsy for Diagnosis of Oral Verrucous Carcinoma: A Multivariate Clinicopathological Study

INTRODUCTION

Studies have reported 20 % of conventional squamous cell carcinoma in patients with verrucous carcinoma (VC), later these cancers were termed as hybrid VC. It is important to distinguish both while planning treatment since hybrid VC requires addressing regional lymphatics in addition to respective surgery. Information on odds of missing the foci of invasion on routine incision biopsy might be useful in this regard.

PATIENTS AND METHODS

Records of all the patients surgically treated for oral cancer from Jan 2010 to Oct 2013 in a Tertiary Cancer Centre was analyzed. Patients diagnosed with primary VC or Verrucous Hyperplasia on incision biopsy were included in the study. Proportion of patients undiagnosed for invasive component on incision biopsy was calculated, multivariate analysis of the sample was performed to find associated cofounders.

RESULTS

Fifty-five patients who reported with the diagnosis of VC (n = 53) or Verrucous Hyperplasia (n = 2) on incision biopsy were included in the study. Twenty-seven were diagnosed as VC and 28 as hybrid VC after excision. This corresponded to 51 % (n = 28) of cases missing invasive component on incision biopsy. VC was significantly more commonly seen in lip and in buccal mucosa, hybrid VC was more commonly seen in tongue and gingiva and this association was statistically significant (p = 0.031) in our study.

CONCLUSION

Incision biopsy is extremely unreliable to diagnose and differentiate oral Hybrid VC from VC or Verrucous Hyperplasia. Caution is required while planning treatment of these patients regarding possibility of presence of conventional squamous cell carcinoma within these tumors.

Multiple verrucous carcinomas of the oral cavity

The author herein reports a case of multiple verrucous carcinomas (VCs) of the left lower gingiva. A 78-year-old man was admitted to our hospital because of gingival tumor. A biopsy revealed severe dysplasia. Surgical resection was performed. Grossly, there were three verrucous lesions (25, 20, 10 mm) in the left lower gingiva. Histologically, 2 tumors (4, 2 mm) were found in addition to the grossly visible 3 tumors. All the 5 tumors were VCs. The tumors showed verrucous and papillary proliferation of squamous epithelium with little cellular atypia. No invasive features were recognized. The dermis showed lymphocytic infiltration. The surrounding mucosa showed many broad foci of squamous cell carcinoma in situ and severe dysplasia (high grade intraepithelial neoplasm). Gradual merges between the VCs and squamous cell carcinoma in situ or severe dysplasia were frequently recognized. Immunohistochemically, the VC tumor cells and squamous lesions were negative for human papilloma virus antigens. P53 protein was expressed in all the VCs and squamous epithelial lesions: it was accentuated in the basal and suprabasal cells of VC. Ki-67 antigen was also expressed in the 5 VCs and in the squamous lesion, and Ki-67 labeling index ranged from 8 to 16 % in VC and from 37 to 62 % in the squamous lesions. These data support the multicentric nature of VC and that the severe dysplasia-carcinoma in situ sequence have been proposed in the etiology of VC.

The clinical significance of CDK1 expression in oral squamous cell carcinoma

Objectives: To evaluate the clinical significance of cyclin-dependent kinase 1 (CDK1) in 77 oral squamous cell carcinomas (OSCC) using immunohistochemical methods. Study Design: Immunohistochemical expression of CDK1 was compared with various clinicopathological features in 77 OSCC and 60 controlled epithelia adjacent to the tumours. In addition, correlation of CDK1 expression and prognostic and the 5-year accumulative survival rate of OSCC were investigated. Results: The CDK1 protein was expressed in 52 cases of 77 tumor tissues (67.5%), compared with 21 cases of 60 controlled (35.0%). The expression of CDK1 was significantly correlated with the histological grade of OSCC (P<0.05). The CDK1 protein was over-expressed in recurrent tumors or in those with lymph node metastasis. Statistical analysis showed a significant reduction in the 5-year accumulative survival rate in CDK1 positive cases compared with CDK1 negative cases (P<0.05). Namely, the CDK1 positive patients had poor prognosis. Conclusions: The expression of CDK1 might serve as malignant degree and prognostic markers for the survival of OSCC.

Key words:Cyclin-dependent kinase 1 (CDK1), oral squamous cell carcinoma (OSCC), immunohistochemistry, cell proliferation.

Expression of Ki-67 in normal oral epithelium, leukoplakic oral epithelium and oral squamous cell carcinoma

Aims and Objective:

To demonstrate the presence, location and pattern of cell proliferation in different histological grades of oral epithelial dysplasia (OED), oral squamous cell carcinoma (OSCC) and normal oral epithelium (NOE) using an antibody directed against the Ki-67 antigen and its intensity of staining evaluated respectively.

Materials and Methods:

A total number of 100 archival paraffin embedded blocks obtained from Department of Oral and Maxillofacial Pathology were studied. The case details were retrieved which consisted of histopathologically diagnosed cases of OSCC (n = 20), low risk OED (n = 30), high risk OED (n = 30) and normal appearing mucosa (n = 20) were taken as standard for comparison. Ki-67 immunostaining was detected. Ki-67 positive cells were counted in the five random high power fields in each case.

Results:

Ki-67 labeling Index (LI) was restricted to the basal and parabasal layers of the normal oral epithelium irrespective of age, sex and site whereas it was seen in the basal, suprabasal and spinous layers in OED. Ki-67 LI is increased in high risk cases than the low risk cases of OED. Ki-67 positive cells in OSCC were located in the periphery of the tumor nests than the center, where frequent mitoses were observed.

Conclusion:

The architectural alteration evaluated by Ki-67 antibody in proliferating cell distribution in the layers of epithelial dysplasias may provide useful information to evaluate the grading of OED. Ki-67 LI increased in high risk cases than low risk cases of OED. This study showed that over expression of Ki-67 antigen between well-differentiated and poorly differentiated OSCC was in accordance with histologic grade of malignancy but not in accordance with moderately differentiated OSCC.

Cytoplasmic expression of HuR may be a valuable diagnostic tool for determining the potential for malignant transformation of oral verrucous borderline lesions

Oral verrucous carcinoma (OVC) is a low grade variant of oral squamous cell carcinoma, and oral verrucous hyperplasia (OVH) is a benign lesion without malignant features. However, pathologists are sometimes presented with borderline lesions and are indecisive as to diagnose them as benign or malignant. Thus, these lesions are tentatively termed oral verrucous lesions (OVLs). HuR is an ARE mRNA-binding protein, normally localized in the nucleus but cytoplasmic exportation is frequently observed in cancer cells. The present study aimed to elucidate whether expression of the HuR protein facilitates the diagnosis of true malignant lesions. Clinicopathological features were evaluated, and immunohistochemical analysis for p53, Ki67 and HuR proteins was performed in 48 cases of OVH, OVC and OVL, and the outcomes were correlated using appropriate statistical analysis. The association of these three proteins in relation to malignant transformation was analyzed after a 3-year follow-up of 25 OVL cases. The basal characteristics (age, gender and location) of all cases had no significant association with the types of lesions. Gingiva (39.4%) was the common site for all lesions. Distribution of the examined proteins had a significant association with the lesions. As compared with the OVLs, the number of immunostained-positive cells was significantly higher in the OVCs and lower in the OVH cases. During follow-up, 24% of the OVLs underwent malignant transformation for which high HuR expression and a diffuse staining pattern in the epithelium were observed. Taken together, the high degree of HuR expression with diffuse staining pattern in the epithelium may be an effective diagnostic tool that determines the potential of OVLs for malignant transformation.

Verrucous carcinoma of the head and neck - not a human papillomavirus-related tumour?

Association between verrucous carcinoma (VC) of the head and neck and human papillomaviruses (HPV) is highly controversial. Previous prevalence studies focused mostly on α-PV, while little is known about other PV genera. Our aim was to investigate the prevalence of a broad spectrum of HPV in VC of the head and neck using sensitive and specific molecular assays. Formalin-fixed, paraffin-embedded samples of 30 VC and 30 location-matched normal tissue samples were analysed, by using six different polymerase chain reaction-based methods targeting DNA of at least 87 HPV types from α-PV, β-PV, γ-PV and μ-PV genera, and immunohistochemistry against p16 protein. α-PV, γ-PV and μ-PV were not detected. β-PV DNA was detected in 5/30 VC (16.7%) and in 18/30 normal tissue samples (60.0%): HPV-19, -24 and -36 were identified in VC, and HPV-5, -9, -12, -23, -24, -38, -47, -49 and -96 in normal tissue, whereas HPV type was not determined in 2/5 cases of VC and in 6/18 normal tissue samples. p16 expression was detected in a subset of samples and was higher in VC than in normal tissue. However, the reaction was predominantly cytoplasmic and only occasionally nuclear, and the extent of staining did not exceed 75%. Our results indicate that α-PV, γ-PV and μ-PV are not associated with aetiopathogenesis of VC of the head and neck. β-PV DNA in a subset of VC and normal tissue might reflect incidental colonization, but its potential biological significance needs further investigation.

Can immunohistochemistry serve as an alternative to subjective histopathological diagnosis of oral epithelial dysplasia?

Many attempts have been made to identify objective molecular biomarkers to diagnose and prognosticate oral epithelial dysplasia (OED) because histopathological interpretation is subjective and lacks sensitivity. The majority of these efforts describe changes in gene expression at protein level in OED as determined by immunohistochemistry (IHC). However, the literature on these putative markers of oral cancer progression is vast and varied. The main purpose of this article is to review current knowledge on biomarkers of protein expression for OED by IHC approaches. We further discuss these findings in terms of the proposed essential hallmarks of cancer cells to better understand their role in oral oncogenesis.

Cyclin B1 overexpression in conventional oral squamous cell carcinoma and verrucous carcinoma- A correlation with clinicopathological features

Background: Nuclear localization of cyclin B1 is an indicator for cells undergoing mitotic division, and the overexpression has shown promising results as a good prognostic predictor for patients of squamous cell carcinoma (SCC). Cyclin B1 overexpression among histological grades of conventional oral squamous cell carcinoma (COSCC), as well as comparison with verrucous carcinoma (VC) has been less investigated. Study Design: Immunohistochemical expression of cyclin B1 was compared with various clinicopathological features in 30 primary COSCC and 31 primary VC cases. Result: Cyclin B1 showed significant overexpression for some clinical features for both the variants of oral squamous cell carcinoma. In histopathological variants, statistical significance was observed among grades of COSCC, as well as COSCC and its grades with VC. The concomitant increase in cyclin B1 overexpression from VC to grades COSCC was observed. Conclusion: Our study findings draw attention to cyclin B1 overexpression is involved in early carcinogenesis, cell differentiation and tumor proliferation.

Key words:Cyclin B1, oral squamous cell carcinoma, verrucous carcinoma, head and neck cancer.

Evaluation of p53 protein as a prognostic factor for oral cancer surgery

We have analysed concentrations of the p53 protein in advanced oral carcinomas immunohistochemically and genetically to detect the percentage of overexpression of this antioncogene that indicates a high probability of mutation. This would point to it being a useful prognostic factor, if we consider the importance of the relation between genetic alterations of p53 and poor overall survival. Seventy-five non-consecutive patients with oral squamous cell carcinoma and metastatic nodes were enrolled if there was homogeneity in histopathological grading (G2) of their tumours, and they were treated according to a multidisciplinary treatment plan. Monoclonal antibodies, extraction of DNA, and amplification of the polymerase chain reaction (PCR) were used for the immunohistochemical and genetic analyses. There was a significant inverse correlation between p53 overexpression and response to chemotherapy and a stronger association between high P53 overexpression (%) and a genetic mutation of p53 (p=0.0001). More than 50% overexpression indicated a strong probability of genetic mutation. There was no association between response to chemotherapy and age-groups or TNM classification (p=0.2), but there was a significant one between sex and site of tumour (p<0.001). Three prognostic factors were significantly related to prognosis: site of tumour (p=0.01), response to chemotherapy (p=0.002), and immuno p53 (p=0.0001). A tumour that is characterised by p53 overexpression of more than 50% indicates a poor prognosis.

Oral verrucous carcinoma mimicking a chronic candidiasis: a case report

Verrucous carcinoma has a special propensity to mimic benign lesions of the oral cavity. A case of the oral verrucous carcinoma in maxillary alveolar ridge, extending to buccal vestibule, cheek, and labial mucosa, which was diagnosed and initially treated as chronic candidiasis, is presented. Clinical, histopathological, and therapeutic considerations related to diagnosis of the verrucous carcinoma in the oral cavity are discussed.

Significance of Ki-67 and p53 immunoexpression in the differential diagnosis of oral necrotizing sialometaplasia and squamous cell carcinoma

Necrotizing sialometaplasia (NS) is a benign condition that usually involves the hard palate and can be mistaken for invasive squamous cell carcinoma (SCC). In this study, we have demonstrated that p53 and Ki-67 staining may assist in the differential diagnosis of NS from SCC. Thirteen cases of NS and 20 cases of oral cavity SCC were randomly selected from our surgical pathology archive from 1992 to 2009. Each case was additionally stained with Ki-67, p53, BCL-2, p16, and epidermal growth factor receptor (EGFR) antibodies. All 13 cases of NS were negatively stained for BCL-2, EGFR, and Ki-67. Three cases (23%) showed weak and focal positive nuclear staining for p53. Two cases (15%) showed positive staining for p16. In 16 well-differentiated SCC cases, p53 was positive in 12 cases (75%); BCL-2, p16, EGFR were positive in 3 cases (18%); and Ki-67 was positive in all cases (100%). In 4 moderately differentiated SCC cases, p53 expression was positive in all cases. Two tumors (50%) had a positive expression of BCL-2. Three cases (75%) had a positive p16 staining, and 1 (25%) had a positive EGFR staining. All cases were positive with high nuclear staining greater than 35% of cells for Ki-67. Ki-67 and p53 showed more intense staining and increased in moderately differentiated SCC comparing with well-differentiated SCC and NS. BCL-2, EGFR, and p16 had the same pattern of staining with the same extent in NS and SCCs. The diagnosis of NS may be difficult and may be supplemented via immunohistochemistry by demonstrating focal or absent p53, low to absent Ki-67 (<10% of cells). Although Ki-67 and p53 staining are generally more intense and are increased in malignancy, these findings may be helpful adjuncts in the differential diagnosis of NS from SCC in appropriate clinical setting.

Verrucous carcinoma of the oral cavity: a histopathologic study of 10 Japanese cases

OBJECTIVE

To reports ten Japanese surgical cases of verrucous carcinoma (VC) of the oral cavity.

STUDY DESIGN

The author reviewed histopathology of 10 cases of oral VC.

RESULTS

Ten cases of oral VC were found in our pathology department in the last 10 years. During the 10 years, a total of 187 cases of oral malignancy were recognized. Therefore, the frequency of VC was 5.3% of all oral malignancies. The patients consisted of six women and four men. The age ranged from 52 to 84 years with a median of 68 years. The locations of VC were buccal mucosa in two cases, gingiva in three cases, hard palate in one case, tongue in three cases, and soft palate in one case. The presenting symptoms were oral discomfort in two cases and tumors in eight cases. All cases underwent surgical resection. Frozen sections were performed in three cases for margin check. Grossly, all cases showed verrucous lesions. The size ranged from 0.8 to 3.2 cm with a median of 1.3 cm. Histologically, tumor cells proliferated with verrucous or papillary features. The tumor cells had acidophilic, ample cytoplasm, and nuclear atypia was minimal. Individual keratinization, koilocytosis, basal cell mild atypia, and squamous pearl formation were recognized in all cases. Three cases showed microinvasion. One case had focal ordinary squamous cell carcinoma within the VC. Epithelial dysplasia in the mucosa was recognized in the vicinity of VC in two cases. One case showed multiple tumors of VC; the number was five. Lymphocytic infiltration in the dermis was recognized in seven cases. Immunohistochemically, p53 protein was positive in all the ten cases. Its location was accentuated near the basal cells and microinvasive parts. Ki-67 positive cells were also seen mainly in the basal cells and in the microinvasive areas, and the KI-67 labeling index ranged from 12 to 21%. Two patients recurred, and additional operations were performed. None show metastatic lesions. One patient died of other disease, and nine patients are now alive without tumors.

CONCLUSION

Clinicopathologic features of ten cases of oral VC were described.

An immunohistochemical analysis of cell cycle markers in oral mucosal dysplastic lesions treated by laser therapy. A pilot study

INTRODUCTION

Over the past 15 years, dysplastic oral mucosal lesions have been treated by laser ablation with variable success. A recent study have shown that the type of laser utilized may be important for patient outcome, however, it may also be changes at a cellular level that could be an important factor in determining recurrence outcome. The aims of this study were to assess cellular markers related to oral dysplastic lesions treated by two different laser types.

METHODS AND MATERIALS

Twenty patients with a histopathological diagnosis of dysplasia treated with laser ablation between the years 1992 and 2003 were assessed. Tissue blocks of the original diagnostic biopsy specimens were stained with specific cell cycle markers (Cyclin-D1 and Ki67) via immunohistochemistry and presence of the marker were analysed by virtual microscopy. Patients were assessed according to grade of dysplasia [(mild vs. moderate vs. severe) and the type of laser used (Potassium Titanyl Phosphate (KTP) vs. Carbon Dioxide (CO(2))].

RESULTS

No significant difference in Cyclin-D1 and Ki67 levels were found between the two groups with different grades of dysplasia, however, decreased Cyclin-D1 was found in those patients treated with KTP laser (P = 0.028).

CONCLUSIONS

The findings of the present study may indicate cell cycle makers such as Cyclin-D1, may be responsible for the behaviour of dysplastic lesions treated with laser therapy, rather than the type of laser itself, which was reported in previous studies.

Ki-67 and ProExC are useful immunohistochemical markers in esophageal squamous intraepithelial neoplasia

Esophageal squamous intraepithelial neoplasia has been widely recognized as a precursor lesion for esophageal squamous cell carcinoma. Early detection offers the best prognosis for esophageal squamous cell carcinoma. The differentiation of squamous dysplasia from reactive change and the classification of squamous dysplasia into high-grade or low-grade are sometimes subjective and challenging. In this study, we sought to evaluate multiple biomarkers and to develop clinically useful adjunct tools for difficult esophageal squamous intraepithelial neoplasia cases. Immunohistochemical stains using antibodies against Ki-67, ProExC, p16, and p53 were performed on esophageal biopsy or resection specimens from 25 patients including 35 foci of high-grade dysplasia and 25 foci of low-grade dysplasia, and from 10 control cases containing 52 foci of normal/reactive hyperplasia. In situ hybridization tests for human papillomavirus were performed in 11 cases. The immunostains for all 4 markers were scored as negative, intermediate, and strong according to established criteria. Intermediate and strong Ki-67 and ProExC staining showed similar detecting power and exhibited very high sensitivity and specificity for distinguishing normal/reactive hyperplasia from esophageal squamous intraepithelial neoplasia and normal/reactive hyperplasia from low-grade esophageal squamous intraepithelial neoplasia. Strong Ki-67 staining was exclusively seen in high-grade esophageal squamous intraepithelial neoplasia, which provided additional value in distinguishing high-grade from low-grade esophageal squamous intraepithelial neoplasia. Strong ProExC staining was also seen in most high-grade esophageal squamous intraepithelial neoplasia foci (80%). Although the frequencies of intermediate/strong staining patterns of p53 increased with increasing degree of dysplasia, the sensitivity of p53 was much lower than that of Ki-67 and ProExC. p16 did not show consistent immunostain pattern in the normal/reactive hyperplasia and esophageal squamous intraepithelial neoplasia. Two (18%) of 11 tested cases were positive for human papillomavirus infection. This study demonstrates that both Ki-67 and ProExC can be used as an adjunct tool for diagnosing difficult cases of esophageal squamous intraepithelial neoplasia.

Verrucous carcinoma of the skin: a report on 5 Japanese cases

Verrucous carcinoma (VC) of the skin is relatively rare. The author reports 5 Japanese cases of VC of the skin. The age ranged from 63 to 91 years with a median of 70 years. The locations were hand in 1 case, lip in 1, face in 1, and foot sole in 2. The size ranged from 0.8 cm to 30 mm with a median of 1.5 cm. Grossly, all the cases showed elevated verrucous tumors. Histologically, the tumors were composed of squamous epithelial cells with minimal cellular atypia arranged in a verrucous pattern. One case showed koilocytosis. Neutrophilic abscesses were seen in 3 cases. Microinvasion was recognized in 2 cases. Focus of less differentiated squamous cell carcinoma was seen in the VC in 1 case. Actinic karatosis or squamous cell carcinoma in situ contiguous to VC was seen in 1 case. Definite precedent lesions were not recognized in any of the cases. Immunohistochemically, VCs of the skin were negative for human papilloma virus antigens in the 2 cases examined. p53 protein was expressed in all the VCs and accentuated in the basal and microinvasive parts. The Ki-67 antigen was also expressed in all the VCs, and it was mainly observed in the basal and microinvasive areas. These findings suggest that (1) VC of the skin can occur in any skin sites, (2) VC of the skin can transform into less differentiated squamous cell carcinoma, and (3) VC of the skin may be associated with squamous cell carcinoma in situ.

Immunohistochemical evaluation of type IV collagen and laminin-332 γ2 chain expression in well-differentiated oral squamous cell carcinoma and oral verrucous carcinoma: a new recommended cut-off

BACKGROUND

Invasion and metastasis are two characteristics of malignant tumors, which perform by proteolytic destruction of the components of basement membrane (BM) and cell migration. The aim of this study was to evaluate the immunohistochemical (IHC) assessment of type IV collagen and laminin-332 γ2 (Ln-332 γ2) chain expression in well-differentiated oral squamous cell carcinoma (OSCC) and oral verrucous carcinoma (OVC), because these two lesions have same histopathologic findings whereas they have different biological behaviors.

METHODS

Destruction of BM and cell migration were evaluated by IHC in 15 cases of epithelial hyperplasia with no dysplasia (A group), 15 cases of OVC (B group) and 15 cases of well-differentiated OSCC (C group).

RESULTS

There was a significant difference in type IV collagen immunohistochemical staining between three groups, but there were no significant differences between B and C groups. Expression of Ln-332 γ2 chain was not detected in A group. Ln-332 γ2 chain labeling index had significantly difference between B and C groups. The number of Ln-332 γ2 chain immunostaining positive cells was less than 5% in B group and over than 5% in C group which there were significantly differences between these two groups.

CONCLUSIONS

Isolated immunohistochemical study of type IV collagen does not clearly define that a lesion is invasive or non-invasive and evaluation of Ln-332 γ2 chain expression (cut-off 5%) may be useful as a marker for description of biological differences and diagnosis of OVC from well-differentiated OSCC, especially in doubtful cases.

Not your usual cancer case: variants of laryngeal squamous cell carcinoma

Although squamous cell carcinoma (SCC) variants account for less than 10% of all laryngeal SCCs, they have many unique biological, morphological, and clinical features. They are also easily confused with other tumor types. Recognition of them is critical for surgical pathologists as is the knowledge of what they mean for the patient. Three of the most common and important of these are basaloid, verrucous, and papillary SCC. These tumor types will be briefly reviewed with a focus on specific controversies, biological questions, and/or recent advancements in our understanding of them.

Oral squamous cell carcinoma versus oral verrucous carcinoma: an approach to cellular proliferation and negative relation to human papillomavirus (HPV)

Human papillomavirus (HPV) has been cited as a possible initiating agent in the pathogenesis of oral cancer. However, the literature tends to be both controversial and inconclusive about the prevalence of HPV and its potential for proliferation in oral squamous cell carcinoma (SCC). The aim of this study was to investigate the cellular proliferation and the presence of HPV in SCC and verrucous carcinoma (VC). Forty-seven samples of SCC were selected and divided into three groups: 39 SCC, 8 VC, and 9 of normal mucosa (control-CT). Quantitative analyses of all groups showed a greater expression of PCNA, followed by Ki-67 and cyclin B1. A significant difference was observed in cyclin B1 expression in the SCC group compared with VC. PCNA, Ki-67, and cyclin B1 were statistically significant when comparing the SCC and CT groups. However, when SCC and VC were compared, there was no difference in Ki-67 expression. Our results showed that only cyclin B1 had an association with histological grade, and that poorly differentiated tumors presented a higher expression of cyclin B1. Therefore, considerable differences in the cellular proliferation between SCC and VC were observed, and no correlation with HPV was established, since all samples were negative for HPV.

PCNA and p53 expression in oral leukoplakia with different degrees of keratinization

Leukoplakias are oral lesions that may have many clinical and histological aspects and they are usually associated with malignancy when dysplastic alterations are shown. However, these transformations may occur in non-dysplastic lesions that show harmless clinical aspect. For this reason, the proposal was to study the p53 and PCNA immunohistochemical expression in non-dysplastic leukoplakias, trying to correlate the results only with the epithelial keratinization degree. For this, 24 leukoplakias degrees I, II and III of Grinspan were used, all of them located in oral mucosa. Most of the leukoplakias showed p53 and PCNA expression in their different keratinization degrees. The p53 marking was confined to the basal and parabasal layers, while the PCNA marking occurred in practically all epithelial layers. The expression pattern of these markers was histologically and statistically similar between the lesions with these keratinization variations. It was evident that non-dysplastic epithelium of leukoplakias showed submicroscopical signs of alterations that lead to malignant transformation, and that the keratinization degree did not correlate to a greater risk of this event.

Frequent alterations of p16INK4a and p14ARF in oral proliferative verrucous leukoplakia

Proliferative verrucous leukoplakia (PVL) represents a rare but highly aggressive form of oral leukoplakia with > 70% progressing to malignancy. Yet, PVL remains biologically and genetically poorly understood. This study evaluated the cell cycle regulatory genes, p16INK4a and p14ARF, for homozygous deletion, loss of heterozygosity, and mutation events in 20 PVL cases. Deletion of exon 1beta, 1alpha, or 2 was detected in 40%, 35%, and 0% of patients, respectively. Deletions of exons 1alpha and 1beta markedly exceed levels reported in non-PVL dysplasias and approximate or exceed levels reported in oral squamous cell carcinomas. Allelic imbalance was assessed for markers reported to be highly polymorphic in squamous cell carcinomas and in oral dysplasias. Loss of heterozygosity was detected in 35.3%, 26.3%, and 45.5% of PVLs for the markers IFNalpha, D9S1748, and D9S171, respectively. INK4a and ARF sequence alterations were detected in 20% and 10% of PVL lesions, accordingly. These data show, for the first time, that both p16INK4a and p14ARF aberrations are common in oral verrucous leukoplakia; however, the mode and incidence of inactivation events differ considerably from those reported in non-PVL oral premalignancy. Specifically, concomitant loss of p16INK4a and p14ARF occurred in 45% of PVL patients greatly exceeding loss reported in non-PVL dysplastic oral epithelium (15%). In addition, p14ARF exon 1beta deletions were highly elevated in PVLs compared with non-PVL dysplasias. These data illustrate that molecular alterations, even within a specific genetic region, are associated with distinct histologic types of oral premalignancy, which may affect disease progression, treatment strategies, and ultimately patient prognosis.

Comparative study of the expression of p53, Ki67, E-cadherin and MMP-1 in verrucous hyperplasia and verrucous carcinoma of the oral cavity

CONTEXT

Oral verrucous carcinoma (OVC) and oral verrucous hyperplasia (OVH) may be clinically and histologically similar. Problems separating these lesions are compounded by poorly oriented tissue sections and biopsies failing to demonstrate lesional margins.

OBJECTIVE

To distinguish OVC from OVH utilizing an immunohistochemical panel (p53, matrix metalloproteinase-1, E-cadherin, Ki67) shown to be useful in differentiating pseudoepitheliomatous hyperplasia from oral squamous cell carcinoma of the head and neck.

MATERIALS

Twenty-eight cases of OVH and thirty-two cases of OVC studied. Diagnoses were confirmed by two pathologists. Formalin-fixed, paraffin-embedded archival material was used for immunohistochemistry (avidin-biotin immunoperoxidase technique).

RESULTS

More diffuse nuclear staining of p53 and Ki67 was detected in the OVC cases compared to the OVH cases (P < 0.001). There was statistically significant increased staining within adjacent stromal cells for matrix metalloproteinase-1 (P < .05) in the OVC cases. E-cadherin demonstrated diffuse membranous staining in both groups.

CONCLUSION

Ki67, p53, and MMP-1 demonstrated significant staining trends. Although a properly oriented hematoxylin-eosin-stained section including normal marginal tissue is considered to be the gold standard for differentiation of OVH and OVC, this immunohistochemistry panel may serve as a useful diagnostic adjunct in difficult cases.

Immunohistochemical detection of p16INK4a in dysplastic lesions of the oral cavity

Significant intra- and interobserver variability exists in diagnosing and grading oral epithelial dysplasia. Mutations in the tumor-suppressor gene p16 are common in oral cavity dysplastic lesions, but whether immunohistochemical detection of the gene product p16(INK4a) (p16) can be used as a reliable biomarker for dysplasia is unclear. In total, 119 biopsy specimens representing various oral cavity sites and degrees of dysplasia were retrieved from the pathology files of Emory University Hospital. Formalin-fixed, paraffin-embedded sections were stained with hematoxylin and eosin (H&E) and with a monoclonal antibody to p16 (LabVision Corporation, Clone JC2). A blinded review of the H&E slides and the pattern and degree of p16 expression was independently performed by two pathologists. A consensus was obtained when diagnoses differed. Morphologic diagnoses were then compared to p16 immunohistochemical expression. Overall, 61/119 (51%) cases showed no p16 immunoreactivity, including 12/33 (36%) cases of no dysplasia, 11/28 (39%) cases of mild dysplasia, and 38/58 (66%) cases of moderate/severe dysplasia. The remaining cases showed p16 expression limited to the basal and suprabasal nuclei and generally confined to the lower one-third of the epithelium. A logistic regression model showed a trend toward absent p16 expression with increasing severity of dysplasia (P=0.006). Decreased expression of p16 in dysplastic lesions, as found in this study, may reflect the biologic events involving loss of p16 gene function in the pathogenesis of oral cancer. Our findings suggest that p16 immunohistochemistry is not helpful in differentiating dysplastic from nondysplastic mucosa in oral cavity biopsies, and thus is not a reliable biomarker for use in routine clinical practice.

Upper aerodigestive tract squamous dysplasia: correlation with p16, p53, pRb, and Ki-67 expression

CONTEXT

Differential expression of cell cycle-associated proteins may correlate with human papillomavirus status and may help delineate degree of dysplasia in upper aerodigestive tract squamous lesions.

OBJECTIVE

To determine intraepithelial height of immunohistochemical staining for p16, p53, pRb, and Ki-67 in upper aerodigestive tract lesions with reference to degree of dysplasia. Human papillomavirus status was ascertained to correlate with p16 expression.

DESIGN

Biopsy specimens of 53 squamous dysplastic and 13 keratotic/hyperplastic lesions were immunohistochemically stained for p16, p53, pRb, and Ki-67. Mean height and proportion of positive staining were quantified and compared for keratotic/hyperplastic, mild, moderate, and severe dysplasia/carcinoma in situ. DNA extracted from paraffin-embedded blocks was evaluated for human papillomavirus by polymerase chain reaction amplification using consensus primers for mucosal viral types.

RESULTS

Height of Ki-67 staining within the epithelium increased significantly between mild and moderate and between mild and severe dysplasia, with a trend toward increasing height between moderate and severe dysplasia. The percentage of cases with p16 staining decreased significantly with increasing degree of dysplasia; however, no significant trend in staining height or proportion was observed with p16, p53, or pRb in relation to degree of dysplasia, or between dysplastic and keratotic/hyperplastic lesions. Only 1 of 53 dysplastic lesions was positive for human papillomavirus.

CONCLUSIONS

This series of upper airway dysplastic mucosal lesions demonstrated a positive correlation between intraepithelial Ki-67 staining height and degree of dysplasia, offering a diagnostic aid in delineating degree of dysplasia in difficult squamous lesions.

Expression of p16INK4A, p53, and Rb proteins are independent from the presence of human papillomavirus genes in oral squamous cell carcinoma

BACKGROUND

The overexpression of p16(INK4A) and suppression of p53 and Rb proteins are key features of oncogenic transformation by human papillomaviruses (HPV) in anogenital cancers. HPV genomes are often detected in cancers of the oral cavity, but it is unclear whether HPV has a specific oncogenic role there.

OBJECTIVES

The objectives of the study were to investigate the expression of p53, Rb, and p16(INK4A) proteins and identify HPV infection and viral integration into the host genome.

METHODS

Seventy-nine cases of oral squamous cell carcinoma (OSCC) were studied by immunohistochemistry. Polymerase chain reaction (PCR) was performed to identify HPV DNA from the samples. The results were correlated with clinical data.

RESULTS

Thirty-three cases were HPV positive for high-risk HPV (HR-HPV) types, of which 27 harbored HPV16. In 25 of 27 HPV16-positive tumors, the HPV16 genome was fully integrated into the host genome, as evidenced by the lack of PCR-amplifiable E2 gene sequences. Forty-five patients were p53 overexpressing, 20 with HR-HPV-positive and 25 with HR-HPV-negative tumors. p16(INK4A) protein was overexpressed in 4 of 31 HR-HPV-positive and 9of 45 HR-HPV-negative cases. Twenty-six of 32 HR-HPV-positive and 37 of 44 HR-HPV-negative samples exhibited pRb nuclear staining. These differences between HR-HPV-positive and -negative tumors were not statistically significant. No correlation was found between these biological factors and tumor location, stage, differentiation grade, or alcohol or tobacco abuse.

CONCLUSIONS

A tumor immunophenotype, similar to HPV-related anogenital cancers, is not present in OSCC and highly oncogenic HPV types are therefore unlikely to be specific or independent risk factors for oral cancer.

Immunohistological evaluation of Ki-67, p63, CK19 and p53 expression in oral epithelial dysplasias

BACKGROUND

Oral squamous cell carcinoma develops through a multistep of genetic mutations, and the process can be morphologically recognized as oral epithelial dysplasia. To evaluate the hypothesis that distributional alterations of proliferating and stem cells may be a useful index to estimate the grading and development of epithelial dysplasia, we examined the distribution patterns according to stratified cell layers.

METHODS

Sixty-two oral dysplasia cases according to the histological grades were immunohistologically examined and the nuclear expression of Ki-67 and p63 antigens was counted according to epithelial layers as labeling index.

RESULTS

The Ki-67 labeling index in the basal and suprabasal layers and that of p63 in the basal layer showed a significant difference between low- and high-grade groups of epithelial dysplasia.

CONCLUSION

The architectural alteration of proliferating cell and stem cell distribution in the layers of epithelial dysplasias may provide useful information to evaluate the grading of oral epithelial dysplasias.

Diagnostic utility of cell cycle and apoptosis regulatory proteins in verrucous squamous carcinoma

A major problem in the diagnosis of verrucous squamous cell carcinoma is the lack of readily reproducible objective criteria for distinguishing this malignant lesion from reactive epithelial hyperplasia. Both lesions are characterized by thickened (well-differentiated) squamous epithelium without cellular atypia and subjacent stroma densely infiltrated by lymphocytes and plasma cells. This study was carried out to evaluate the use of cell cycle and apoptosis-related regulatory proteins in the diagnosis of verrucous carcinoma. The study materials consisted of representative formalin-fixed and paraffin-embedded tissue blocks from 19 cases of verrucous carcinoma, 18 classic squamous cell carcinoma, and 14 squamous epithelial hyperplasia (acanthosis). The immunohistochemical expression of the following of cell cycle and apoptosis-related regulatory proteins was evaluated using avidin-biotin complex detection technique: p16, p21, p53, Ki67, and retinoblastoma gene product (RBGP) (also known as retinoblastoma protein [pRb]). Expression of Ki67 was detected only in the single basal layer of the epithelium in all 14 cases of acanthosis. In verrucous carcinoma, Ki67 was detected in basal and suprabasal cells in the lower third of the neoplastic epithelium in 19 of 19 cases (100%). In neoplastic squamous epithelium with frankly invasive squamous cell carcinoma, Ki67 was diffusely expressed throughout the entire thickness of the epithelium as well as in the underlying invasive tumor nests. The pattern of p53 expression was similar to that of Ki67 in all the experimental groups, with a Pearson correlation coefficient of 0.98. In addition, immunohistochemical expression of p53 in the hyperplastic squamous epithelium was very weak, in contrast to the more intense immunoreactivity observed in verrucous carcinoma and classic squamous cell carcinoma. There was an overlapping in the expression of p16, p21, and RGBP in all the experimental groups, being present in more than half the thickness of the epithelium in 50% to 100% cases in each study group. We therefore conclude that the pattern of Ki67 and p53 expression in verrucous carcinoma is readily reproducible and distinctly different from that observed in epithelial hyperplasia and that seen in invasive squamous cell carcinoma. Thus Ki67, and p53 immunostains are reliable adjuncts that may be helpful in resolving diagnostic problems associated with verrucous carcinoma.

Immunohistochemical assessment of Viadent-associated leukoplakia

Studies show an association between sanguinarine, the active ingredient in Viadent oral health care products, and oral premalignant lesions. The study was undertaken to quantitatively compare the staining profiles of sanguinarine-associated leukoplakia to normal and dysplastic specimens. Archived oral mucosal specimens were stained for tumor markers p16, p53, cyclin D1, Ki-67, and Bcl-x and analyzed through Simple PCI image analysis software. Quantitative analyses showed trends towards intermediate staining in Viadent-related specimens (Ki-67: normal: 18.12+/-2.15, Viadent: 16.12+/-2.16, dysplasia: 14.53+/-2.04, p>0.05; cyclin D1: normal: 15.65+/-3.68, Viadent: 12.52+/-3.57, dysplasia: 1.94+/-3.93, p<0.05; p16: normal: 55.04+/-4.16, Viadent: 49.74+/-4.16, dysplasia: 45.03+/-4.45; p>0.05; p53:normal: 2.65+/-1.37, Viadent: 4.64+/-1.52, dysplasia: 8.71+/-1.37; p<0.05 Kruskal Wallace, Tukey/Kramer). Our Viadent profiles, intermediate between normal and dysplasia, support a preneoplastic nature of this process.

HPV-18 confers resistance to TNF-alpha in organotypic cultures of human keratinocytes

The proinflammatory cytokine tumor necrosis factor-alpha (TNF-alpha) inhibits normal keratinocytes proliferation. However, many human papillomavirus (HPV)-immortalized or transformed cell lines are resistant to TNF-alpha antiproliferative effect. The present study analyzes the effects of TNF-alpha on organotypic cultures of primary human keratinocytes (PHKs) that express HPV-18 oncogenes. Raft cultures prepared with PHKs acutely transfected with HPV-18 whole genome or infected with recombinant retroviruses containing only E6/E7 or E7 were treated with 2 nM TNF-alpha. While BrdU incorporation into basal/parabasal cells of normal PHKs cultures was markedly inhibited by TNF-alpha cultures transfected with HPV-18 whole genome showed proliferation in all cell strata. Furthermore, BrdU incorporation into cultures expressing E6/E7 or E7 was not significantly reduced, indicating that E7 alone confers partial resistance to TNF-alpha. Besides, TNF-alpha treatment did not alter p16ink4a, p21cip1, p27kip1, or cyclin E levels, but did reduce cyclin A and PCNA levels in sensitive cells.

The molecular markers for prognostic evaluation of areca-associated buccal squamous cell carcinoma

BACKGROUND

Buccal squamous cell carcinoma (BSCC) is the most frequently occurring oral cancer in Asians due to the popularity of areca use in this area. The aim of the present study was to evaluate the survival of areca-associated BSCC associated with multiple molecular markers.

METHODS

Using immunohistochemistry, we evaluated the survival of a cohort of 55 patients with BSCC being followed long term, as correlated to the expression of variable markers.

RESULTS

We found that p53, p21, Rb, cyclin D1 (CCD1), MDM2, and gamma-catenin were positive in 81, 60, 70, 31, 88, and 44% of patients, respectively. Subjects with -ve immunoreactivity for CCD1, and +ve immunoreactivity for MDM2 and gamma-catenin had significantly better survival than subjects with the opposite immunoreactive pattern. KAPLAN-meier survival curves confirmed this association.

CONCLUSION

The data indicate that expression of CCD1, MDM2, and gamma-catenin might serve as potential prognostic markers for BSCC in areca-using patients.

Alteration of the fragile histidine triad gene early in carcinogenesis: an update

An association between common chromosome fragile sites and frequent chromosomal deletions in cancer has been observed and led to the hypothesis that genes at fragile sites may play a role in tumor development. In 1996, the human fragile histidine triad gene, FHIT, was identified by positional cloning at 3p14.2, a chromosomal region spanning the carcinogen-sensitive, common fragile site FRA3B. FHIT gene is lost and inactivated in a large fraction of tumors and early in carcinogenesis. A group of ancestral cancerous cells that carry FHIT alterations, expanding in succeeding cell generations, exhibits a hallmark in carcinogenesis scenario.