Tissue markers of potentially malignant human oral epithelial lesions

Biomarkers in Head and Neck Cancer an Update

The study is aimed at establishing the purpose of tumour markers, their application, classification, diagnostic and therapeutic roles in the management of head and neck cancer. A literature review using Medline, Scopus, Google Scholar, the Cochrane Database of Systematic Reviews and the Cochrane central register of controlled trials for articles published between 1993 and 2016 on tumour markers and their role in head and neck cancer was performed. A broader search of prognostic markers in head and neck cancer was also carried out to avoid missing other pertinent markers. Natural history, tumour biology, stage and prognostic factors influence the outcome of management in patients with Head and Neck Squamous cell carcinoma (HNSCC). Evaluation of the cellular lineage and histogenic origin of diverse neoplasms can be done using tumour biomarkers. Identifying predictive tumour markers can lead to improvement in preventive management of HNSCC. There has been remarkable advancement in molecular technology with gene expression and proteomic profiling. Integration of specific tumour markers into routine clinical practice requires substantiation through well designed clinical trials. The investigation of tumour markers is imperative as they influence the prognosis of HNSCC and provide the potential to improve outcomes of treatment through targeted therapy. We have outlined recent tumour biomarkers in this review which have significant role in diagnosis, screening and prognostication in HNSCC. Recent advancement in clinical applications, therapeutic strategies of tumour markers has been highlighted.

Genomic DNA Copy Number Aberrations, Histological Diagnosis, Oral Subsite and Aneuploidy in OPMDs/OSCCs

Oral potentially malignant disorders (OPMDs) characterized by the presence of dysplasia and DNA copy number aberrations (CNAs), may reflect chromosomal instability (CIN) and predispose to oral squamous cell carcinoma (OSCC). Early detection of OPMDs with such characteristics may play a crucial role in OSCC prevention. The aim of this study was to explore the relationship between CNAs, histological diagnosis, oral subsite and aneuploidy in OPMDs/OSCCs. Samples from OPMDs and OSCCs were processed by high-resolution DNA flow cytometry (hr DNA-FCM) to determine the relative nuclear DNA content. Additionally, CNAs were obtained for a subset of these samples by genome-wide array comparative genomic hybridization (aCGH) using DNA extracted from either diploid or aneuploid nuclei suspension sorted by FCM. Our study shows that: i) aneuploidy, global genomic imbalance (measured as the total number of CNAs) and specific focal CNAs occur early in the development of oral cancer and become more frequent at later stages; ii) OPMDs limited to tongue (TNG) mucosa display a higher frequency of aneuploidy compared to OPMDs confined to buccal mucosa (BM) as measured by DNA-FCM; iii) TNG OPMDs/OSCCs show peculiar features of CIN compared to BM OPMDs/OSCCs given the preferential association with total broad and specific focal CNA gains. Follow-up studies are warranted to establish whether the presence of DNA aneuploidy and specific focal or broad CNAs may predict cancer development in non-dysplastic OPMDs.

Molecular predictors in the early diagnosis of oral cancer

Human beings are being subjected to a variety of disease processes, a majority of which can be cured. However, cancer remains an endangering disease that affects various body parts. Though cancers can be prevented by various therapeutic modalities, the patient survival and the prognosis are questionable, as they are detected at very late stages. The aim of improving the prognosis lies in an early detection of the cancer, which can be brought about by an analysis of the changes in the cellular biomolecules.

Chromosomal instability, aneuploidy and routine high-resolution DNA content analysis in oral cancer risk evaluation

Carcinogen exposure of the oral cavity is thought to create an extensive 'field cancerization'. According to this model, a very early precursor of oral cancer is a patch of normal-appearing mucosa in which stem cells share genetic/genomic aberrations. These precancerous fields then become clinically visible as white and red lesions (leuko- and erythro-plakias), which represent the vast majority of the oral potentially malignant disorders. This review focuses on aneuploidy (where it is from) and on biomarkers associated with DNA aneuploidy in oral mucosa and oral potentially malignant disorders, as detected by DNA image and flow cytometry. Data from the literature strongly support the association of DNA ploidy with dysplasia. However, work is still needed to prove the clinical value of DNA ploidy in large-scale prospective studies. Using high-resolution DNA flow cytometry with fresh/frozen material and the degree of DNA aneuploidy (DNA Index) might improve the prediction of risk of oral cancer development.

Expression of epithelial growth factor receptor in oral epithelial dysplastic lesions

Aim:

The aim of the study was to assess the expression of epithelial growth factor receptor (EGFR) in normal oral mucosa and varying grades of oral epithelial dysplasia (OED) and to correlate these findings, with clinicopathologic features and findings on routine hematoxylin and eosin–stained (H and E) sections.

Materials and Methods:

Twenty-nine formalin-fixed, paraffin-embedded blocks of various grades of OED and 10 normal mucosa were stained with routine H and E and immunostained with EGFR by avidin–biotin method.

Results:

The results showed a significant increase in the staining reactions in varying grades of dysplasia as compared with normal mucosa.

Conclusion:

EGFR can be considered as an early marker of a cell proliferation and maturation as well as early marker of epithelial dysplasia and onset of cancer in oral dysplasia. However, further studies with a larger sample size and continuous followup is suggested to determine its role and significance precisely.

Expression of p53 in leukoplakia and squamous cell carcinoma of the oral mucosa: correlation with expression of Ki67

Aim-To study p53 expression in relation to proliferative status in normal and nondysplastic, dysplastic and malignant lesions of the oral mucosa.Method-The standard avidin-biotin complex (ABC) immunohistochemical staining method was used to study the expression of p53 and Ki67 on frozen sections of oral leukoplakias and carcinomas.Results-Of the leukoplakia and carcinoma samples, 70% expressed p53 in over 5% of cells. In normal mucosa less than 5% of cells expressed p53. The proliferation index, as assessed by expression of Ki67, was highest in the malignant lesions (43%) and lowest in normal mucosa (11%). Statistical analysis revealed that expression of both p53 and Ki67 was correlated significantly with the histopathological stage of the tumour. However, expression of p53 was not correlated with that of Ki67. In leukoplakia lesions with proliferative features p53 immunostaining was less intense than in non-proliferative lesions; this difference was statistically significant.Conclusions-These results emphasise the potential of Ki67 and p53 as biomarkers of carcinogenesis in oral cancer and may also serve as intermediate points for cancer prevention programmes, such as the oral chemopreventive trials. Factors other than p53 may have a more important role in the deregulation of proliferation in pre-malignant oral lesions.

DNA aneuploidy and dysplasia in oral potentially malignant disorders: association with cigarette smoking and site

To date there are still no reliable biomarkers for oral potentially malignant disorders (PMDs) to predict the risk of progression to squamous cell carcinoma (SCC). Within a prospective clinical trial of patients with PMDs, DNA content flow cytometry (DNA FCM) was evaluated for 60 PMDs using fresh samples obtained by a dermatological curette. There were 6/42 PMDs without dysplasia, but with DNA aneuploidy, versus 8/18 with both dysplasia and aneuploidy (p=0.02). When the tongue and the buccal mucosa, the two most common sites in the present series of cases were compared, dysplastic PMDs were mainly located on the tongue (p=0.01). Tobacco smokers, who preferentially developed PMDs in the buccal mucosa at a younger age than non-smokers (p=0.002), had fewer dysplastic PMDs than did non-smokers (p=0.01). Dysplasia was significantly linked to DNA aneuploidy (p=0.03) in smokers. The present data suggest that aneuploidy is an early event in oral carcinogenesis and that the influence of tobacco varies according to subsite and patient age. When DNA FCM of PMD samples are obtained by curette scraping, extensive areas can be covered with a minimally invasive, rapid, inexpensive procedure. Moreover DNA FCM of these samples appears easy amenable to routine analysis. Further research on larger numbers of PMDs should be carried out to determine whether DNA FCM plays a role in the prediction of risk of PMD transformation.

Genetic portrait of mild and severe lingual dysplasia

Squamous cell carcinoma is the most frequent malignant tumor of the oral cavity and often arises from premalignant lesions. Traditional methods used by the pathologist are subjective and lack the sensitivity to predict accurately which precancers may progress with time. Therefore, it is important to search for markers that may identify progression of premalignant lesions. Microarray technology can be use with this aim. Here, we define the genetic expression profile of lingual dysplasia (DS) progression. By using cDNA microarray containing 19.2K clones and a baseline of 11 normal tissues, we compared 5 mild and 4 severe DS. We identified 270 genes differentially expressed in normal tissue vs. mild DS (i.e. 161 up- and 109 down-regulated) and 181 genes differentially expressed in mild vs. severe DS (i.e. 63 up- and 118 down-regulated). The described genes cover a broad range of functional activities: (a) anti-oxidative, (b) DNA-repair, (c) inflammatory response, (d) cell-adhesion/mobility, (e) extracellular matrix depolymerization, and (f) cell-cycle regulation. The data reported better define DS progression and can help in classifying premalignant lesions.

Expression of heat shock protein (HSP70) in oral lichen planus and non-dysplastic oral leucoplakia

The purpose of this study was to investigate the expression of heat shock protein (HSP70) in oral non-dysplastic leucoplakia and in relation to the clinical and pathological features of oral lichen planus. The expression of HSP70 was assessed in the epithelial compartment of normal mucosa (n = 5), oral lichen planus (n = 28) and benign leucoplakia (n = 11) using an immunohistochemical method. The immunostaining intensity distribution (IID) index was used to quantify the positivity of the staining. There was no association between HSP70 overexpression and clinical presentation of oral lichen planus. Oral lichen planus patients showed no statistically significant differences in the depth of the inflammatory infiltrate when expression of HSP70 was considered (X(i)- X(j) = 42.30; 95% confidence interval (95% CI) = -120.87-205.48). No statistically significant differences were identified in terms of HSP70 expression between oral lichen planus and normal buccal mucosal specimens (X(i)- X(j) = 4.07; 95% CI = -0.53-8.67). The IID index score for HSP70 expression in leucoplakia specimens was significantly higher than the one of the oral lichen planus group (X(i) - X(j)= 5.11; 95% CI = 1.73-8.48). It is concluded that there are no statistically significant differences in HSP70 expression between oral lichen planus and normal buccal mucosal specimens, suggesting that HSP70 does not play an obvious part in the pathogenesis of oral lichen planus. The expression of HSP70 was significantly higher in oral leucoplakia than in oral lichen planus, possibly because of differences in cellular activity or cell proliferation.

Prognosis of oral pre-malignant lesions: significance of clinical, histopathological, and molecular biological characteristics

The concept of a two-step process of cancer development in the oral mucosa, i.e., the initial presence of a precursor subsequently developing into cancer, is well-established. Oral leukoplakia is the best-known precursor lesion. The evidence that oral leukoplakias are pre-malignant is mainly derived from follow-up studies showing that between < 1 and 18% of oral pre-malignant lesions will develop into oral cancer; it has been shown that certain clinical sub-types of leukoplakia are at a higher risk for malignant transformation than others. The presence of epithelial dysplasia may be even more important in predicting malignant development than the clinical characteristics. Three major problems, however, are attached to the importance of epithelial dysplasia in predicting malignant development: (1) The diagnosis is essentially subjective, (2) it seems that not all lesions exhibiting dysplasia will eventually become malignant and some may even regress, and (3) carcinoma can develop from lesions in which epithelial dysplasia was not diagnosed in previous biopsies. There is, therefore, a substantial need to improve the histologic assessment of epithelial dysplasia or, since epithelial dysplasia does not seem to be invariably associated with or even a necessary prerequisite for malignant development, it may be necessary to develop other methods for predicting the malignant potential of pre-malignant lesions. As a consequence of these problems, numerous attempts have been made to relate biological characteristics to the malignant potential of leukoplakias. Molecular biological markers have been suggested to be of value in the diagnosis and prognostic evaluation of leukoplakias. Markers of epithelial differentiation and, more recently, genomic markers could potentially be good candidates for improving the prognostic evaluation of precursors of oral cancer. As yet, one or a panel of molecular markers has not been determined that allows for a prognostic prediction of oral pre-cancer which is any more reliable than dysplasia recording. However, these new markers could be considered complementary to conventional prognostic evaluation.

Progress in determining the malignant potential of oral lesions

The dilemma in managing patients with potentially malignant oral lesions and field change is of deciding which mucosal lesions or areas will progress to carcinoma. Although dysplasia may be predictive, this is not invariable, and there can be considerable inter- and intraexaminer variation in that diagnosis. Recent data on molecular and DNA changes in potentially malignant lesions suggest that it is now feasible to identify those lesions that are truly potentially malignant.

The aggressive nature of the odontogenic keratocyst: is it a benign cystic neoplasm? Part 3. Immunocytochemistry of cytokeratin and other epithelial cell markers

Numerous studies of keratin expression by the more common odontogenic cysts were done to determine whether patterns of cytokeratin staining could provide accurate diagnostic markers for the different varieties; to see whether comparative studies with oral mucosa and developing odontogenic epithelium could explain the pathogenesis of the cysts; and whether cytokeratin patterns could provide clues in elucidating the aggressive nature of the OKC. This review was a complex task with a range of at least 19 different cytokeratins being studied and also a broad range of antibodies in use for the same cytokeratin or group of cytokeratins. Moreover, there was not always standardisation of laboratory techniques in the selection and preparation of material. These difficulties were, in general, recognised by the different workers in the field, particularly when there was disagreement on results and caution was expressed about drawing conclusions from some positive findings. It would be fair to conclude that cytokeratin immunocytochemistry has not advanced to any meaningful extent, its use as a diagnostic marker for the OKC nor in eludidating its pathogenesis. With regard to OKC behaviour, it has been pointed out that there was strong reaction of OKC lining for keratin 16, a cytokeratin that has been associated with high proliferative activity. Yet other studies have also shown keratin 16 expression in dentigerous and radicular cysts. Differences in cytokeratin, EMA and CEA immunocytochemical reactivity between the parakeratinised and orthokeratinised varieties of cyst were demonstrated and the suggestion made that the orthokeratinised type has a considerably less aggressive behaviour, is a different entity and should bear a different name. Furthermore, Ki67 positive cells in the parakeratinised OKC linings were considerably more frequent than in the orthokeratinised linings.OKC, dentigerous and radicular cyst epithelium reacted positively for epithelial growth factor receptor (EGFr) but a trend indicating the most intense staining in the OKCs, followed by the dentigerous and then the radicular cyst linings led to the conclusion that the OKCs have an intrinsic growth potential not present in other odontogenic cysts.

Ki-67 expression in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising from dental cysts

This study investigated whether or not an ameloblastoma developing in the wall of a dentigerous cyst is a distinct lesion from the unicystic ameloblastoma. An immunohistochemical evaluation of Ki-67 in dentigerous cysts, unicystic ameloblastomas, and ameloblastomas arising in dentigerous cysts was done. The values of Ki-67 positivity were 3.14 for the dentigerous cyst, between 5.32 and 16.56 for unicystic ameloblastoma, and 11.77 for ameloblastoma arising in a dentigerous cyst. Statistically significant differences were found between the dentigerous cyst and the unicystic ameloblastoma and between the dentigerous cyst and the ameloblastoma arising from a dentigerous cyst. No statistically significant difference was present between unicystic ameloblastoma and ameloblastoma arising from dentigerous cyst. These immunohistochemical data confirm the hypothesis that an ameloblastoma arising from a dentigerous cyst has a similar biological behavior to the unicystic ameloblastoma and should be considered as merely a histologic variant.

Genetic aberrations in oral or head and neck squamous cell carcinoma 3: clinico-pathological applications

The molecular changes in malignant epithelium in the head and neck offer possibilities for the development of diagnostic, prognostic and other markers. This article reviews recent developments in this field.

Surfing prognostic factors in head and neck cancer at the millennium

The ability to reliably predict cancer outcome could tailor therapy to the aggressiveness of the tumour to achieve the best results in terms of loco-regional control, overall survival and quality of life. Retrospective and prospective clinical trials involving large series of patients have validated some predictive clinical and pathological factors, whereas the utility of many other prognostic factors has not been established. This has led to some confusion in clinical practice. In order to clarify the significance, role and cost of these prognostic factors we carried out a Medline search of all papers published between 1993 and 1998 concerning the reliability and cost of markers with prognostic significance, in head and neck squamous cell carcinoma, and assessed the results according to a number of criteria relating to reliability and cost. Regarding reliability we classified prognostic factors into: (1) those with a proven significance based on the fact that they were unanimously reported as having an independent statistical correlation with outcome and prognosis; and (2) those for which results were not unanimous, and which significance is still controversial. Cost analysis showed a substantial difference between validated tests which are of low cost and experimental tests which are expensive. Based on these data regarding both the reliability and cost of each prognostic factor, we propose guidelines for their use in clinical practice in the year 2000.

Oral cancer: role of the basement membrane in invasion

Invasive growth of cancer cells is a complex process involving specific interactions between tumour cells and the orderly, integrated complexes of the extracellular matrix. Basement membranes have been proposed as one constituent of extracellular matrix which carries responsibility for regulating invasion and metastasis. Using a chemically induced rat tongue carcinoma model, it has been shown that components of the basement membrane and its overall structure are altered during tumour invasion, and methods have been developed to quantitate some of these differences. Since the basement membrane can be specifically characterized by its fibrous protein network of Type IV collagen and laminin, which is embedded in a heparan sulphate-rich proteoglycan matrix, these components have been targeted. In particular, the current paper presents results in the context of current concepts of early changes in neoplastic invasion of underlying connective tissues. In consequence, further elaboration of the underlying mechanisms of epithelial migration in oral cancer may allow an exploration of the use of alterations in expression of basement membrane components as prognostic indicators.

A comparison of the management of potentially malignant oral mucosal lesions by oral medicine practitioners and oral & maxillofacial surgeons in the UK

This study describes the results of a survey undertaken to assess the management of potentially malignant oral mucosal lesions by oral medicine practitioners and compares their approach with that of oral & maxillofacial surgeons that we have previously described. Significant differences were noted between the two groups in the use of photography to document the lesions and in the use of certain special investigations, which included measurement of serum iron, serum ferritin, serum Vit B12, red cell folate and candidal isolation. The groups also varied in the perceived importance of the age of the patient and anatomical site of the lesion when deciding on the need for further biopsy. There was also significant variation in the use of certain treatment modalities, including excising non-dysplastic and severely dysplastic/carcinoma in-situ lesions and eliminating trauma when treating mild/moderately dysplastic and severely dysplastic/carcinoma in-situ lesions. Significant differences in the frequency and duration of follow-up were noted for non-dysplastic lesions. Finally, the two groups differed significantly when asked to rank the perceived importance of certain factors (the histopathology of the most recent biopsy and the anatomical site of the lesion) when deciding the need to follow-up. Possible reasons for the variation are discussed.

Epithelial p53 gene expression and mutational analysis, combined with growth fraction assessment, in oral lichen planus

The immunohistochemical detection of epithelial p53 protein expression in oral lichen planus (OLP) biopsies was supplemented with molecular analysis for mutations of the p53 gene using the polymerase chain reaction - single stranded conformational polymorphism (PCR-SSCP) technique. p53 protein expression, in the basal epithelial cell layer, as detected by the DO7 and 1801 antibodies, was significantly more frequent in OLP compared with other oral keratoses and normal mucosa, as was the growth fraction. The 10 OLP biopsies that had the most frequent p53 staining (plus a case of OLP found in continuity with a SCC) were screened by the PCR-SSCP technique, but no mutations were detected in the p53 gene (exons 5 9). The p53 overexpression in the OLP samples may be a physiological response to the hyper-proliferative state, as revealed by the growth fraction determination. This may usefully serve to protect against mutagenesis, and so be a factor in the low incidence of carcinoma associated with OLP.

Altered expression of alpha 6 integrin subunit in oral squamous cell carcinoma and oral potentially malignant lesions

The expression and distribution of integrin chains alpha 2, alpha 3, alpha 5, alpha 6, beta 1, beta 4, collagen type IV, laminin 1 and laminin 5 in oral squamous cell carcinoma (SCC) and oral keratoses with and without dysplasia (OL) have been studied by immunochemistry and western blotting. Focal interruptions of basement membrane protein staining were detected in SCC indicating a loss of continuity, whereas tumour nests were apparently completely surrounded by laminin 1, type IV collagen and laminin 5; the loss of basement membrane components in OL was found in only one specimen showing severe dysplasia. The localisation of integrins showed altered suprabasal and pericellular expression of the alpha 6 chain in all but one SCC, as well as in many OL samples, whereas the beta 4 subunit showed only a faint pericellular redistribution in SCC. In OL, beta 4 was often seen in a normal basally polarised distribution. Western blotting analysis confirmed that alpha 6 protein levels were abnormally high in cancerous lesions, whereas quantitative recovery of the beta 4 subunit in SCC was only minimal, suggesting a dissociation in the synthetic ratios of the two chains of the alpha 6 beta 4 heterodimer in SCC. Because alterations in the polarised expression of integrin alpha 6 beta 4 have been seen during epithelial tumour progression and wound healing, we suggest that the lack of restricted basal polarisation of alpha 6 could be an early but non-specific marker of oral malignancy, indicating that the generation of abnormal signals from the extracellular matrix may be involved.

Oral leukoplakia: a clinicopathological review

Leukoplakia is the most common premalignant or potentially malignant lesion of the oral mucosa. It seems preferable to use the term leukoplakia as a clinical term only. When a biopsy is taken, the term leukoplakia should be replaced by the diagnosis obtained histologically. The annual percentage of malignant transformation varies in different parts of the world, probably as a result of differences in tobacco and dietary habits. Although epithelial dysplasia is an important predictive factor of malignant transformation, it should be realized that not all dysplastic lesions will become malignant. On the other hand non-dysplastic lesions may become malignant as well. In some parts of the world the tongue and the floor of the mouth can be considered to be high-risk sites with regard to malignant transformation of leukoplakia, while this does not have to be the case in other parts of the world. The cessation of tobacco habits, being the most common known aetiological factor of oral leukoplakia, has been shown to be an effective measure with regard to the incidence of leukoplakia and, thereby, the incidence of oral cancer as well. Screening for oral precancer may be indicated in individuals at risk.

Assessing the patient at risk for oral squamous cell carcinoma

Patients and health care workers require continuing education to promote knowledge of the signs, symptoms, and risk factors for oral cancer. This paper reviews the literature assessing diagnostic tools that are currently available or being developed, in order to assist in the biopsy site selection and subsequent diagnosis of patients at risk for oral cancer. There is a general consensus that oral examination of patients at risk for oral squamous cell carcinoma (SCC) should be conducted on a routine basis. However, there can be false-positive and false-negative findings. Toluidine blue has been shown to be useful as an adjunct to the clinical examination when used by experienced clinicians. Exfoliative cytology is not currently used as a routine measure for the evaluation of lesions of the oral mucosa, but further development and the application of biologic markers to cytologic specimens may increase its value. Fluorescent imaging of malignant lesions of the oral mucosa has been shown to be sensitive and specific in animal models but thus far has been reported in only one human trial. The sensitivity and specificity of these techniques when used by general practitioners need to be assessed. Further, none of the above procedures has yet been shown to be a cost-effective public health measure in screening for oral cancer.

Morphological assessment of malignant potential of epithelial hyperplastic lesions

The spectrum of conventional and advanced morphological methods for the assessment of malignant potential of precancerous lesions of the laryngeal mucosa is discussed.

Argyrophilic nucleolar organizer regions staining is useful in predicting recurrence-free interval in oral tongue and floor of mouth squamous cell carcinoma

BACKGROUND

Argyrophilic nucleolar organizer regions (AgNORs) represent a tissue marker of cell proliferative activity. The purpose of this study was to assess the prognostic value of AgNORs expression in oral squamous cell carcinoma (SCC).

METHODS

The AgNORs area/nucleus was studied in paraffin sections by means of digital image analysis in 43 cases of stage II oral tongue and floor of the mouth SCC.

RESULTS

Time free of disease was considered a dependent variable of a binary indicator of AgNORs expression (7.77 microns2/nucleus as a cut-off point). High AgNORs level was associated with a statistically significant negative effect on recurrence-free interval of disease in a Cox proportional hazards models controlled for occult lymph node metastasis, involvement of the surgical margins, thickness of the lesion, and vascular invasion.

CONCLUSIONS

The AgNORs area increased the capability of predicting which patients have a high risk of recurrence of cancer, and its evaluation may provide useful information for the therapeutic approach to the oral tongue and floor of the mouth SCC.

Oral lichen planus and its association with squamous cell carcinoma: an update on pathogenesis and treatment implications

Lichen planus of the oral mucosa (OLP) is characterized by lymphocytic mucositis, basal cell lysis, and lymphocyte transmigration into the epithelial compartment. Some reports have suggested a high incidence of oral squamous cell carcinoma (OSCCA) in OLP patients and have implicated OLP as a premalignant lesion. We describe five cases of OSCCA arising in patients with preexisting OLP. At our institution, the incidence of OSCCA in patients with OLP approximates that reported in other series. The immunopathologic basis for OLP, its potential association with malignancy, and the variable clinical picture of OSCCA in patients with OLP are reviewed. Specific recommendations are given for treatment and follow-up of lesions, including the role of future testing with viral and oncogene markers.

Increased expression of a 38kd cell-surface glycoprotein MH99 (KS 1/4) in oral mucosal dysplasias

A "window of expression" of a 38-kD cell-surface glycoprotein MH99 (KS 1/4 antigen) has been observed in dysplastic oral tissues using an MH99-specific monoclonal antibody. It appeared that expression of this epitope increases from baseline levels in normal oral epithelium to that of high levels in mild, moderate and severe dysplasia. In invasive squamous cell carcinoma, relatively low levels of expression were observed. In contrast, high levels of expression were demonstrated in basal cell carcinomas. Antibody reactivity could clearly distinguish between the margins of histologically normal and dysplastic tissues. It is envisaged that the expression of this cell-surface glycoprotein, which is possibly related to nidogen, a matrix-adhesion molecule with receptor-like function, could be used in monitoring progression or regression of these lesions and assessment of surgical excision margins. It could also be useful in in vivo and in vitro investigations into molecular changes underlying the formation of dysplastic lesions.

Immunohistochemical demonstration of epithelial glutathione S-transferase isoenzymes in normal, benign, premalignant and malignant human oral mucosa

The expression and localization of glutathione S-transferase (GST) isoenzymes in the epithelium of normal oral mucosa (n = 9), overlying reactive fibrous hyperplasia (n = 9), and of potentially malignant [leukoplakia (n = 25), submucous fibrosis (n = 12), verrucous hyperplasia (n = 16)] and malignant [squamous cell carcinoma (n = 36), verrucous carcinoma (n = 13)] oral lesions were examined immunohistochemically using polyclonal antibodies raised against GST isoenzymes (alpha, mu and pi) with the standard avidin-biotin-peroxidase complex (ABC) method. GST alpha, mu and pi were almost completely absent in the epithelium of normal oral mucosa and overlying benign fibrous tissues. GST alpha staining was cytoplasmic and focally positive, while GST mu staining was similar to but weaker than that seen for GST alpha. GST pi showed both cytoplasmic and nuclear staining and was expressed in 60% of leukoplakias with mild dysplasia (n = 15), 80% of leukoplakias with moderate to severe dysplasia (n = 10). 75% of submucous fibrosis samples (n = 12), 75% of verrucous hyperplasias (n = 16), 77% of verrucous carcinomas (n = 13), 81% of well-differentiated squamous cell carcinomas (n = 26) and 70% of moderate- to poorly-differentiated squamous cell carcinomas (n = 10). In addition, GST pi expression was independent of the state of differentiation of oral cancers. Since GST pi was significantly over-expressed in the oral premalignant and malignant lesions, the kinetics of GST pi-positive cells and the value of GST pi as a tumor marker in oral carcinogenesis need further investigation.

Intraoral squamous cell carcinoma in human immunodeficiency virus infection. A clinicopathologic study

The purpose of this study was to characterize the clinical and histological features of intraoral squamous cell carcinoma in men who were seropositive for the human immunodeficiency virus and to evaluate viral cofactors (human papillomavirus, herpes simplex virus, Epstein-Barr virus), proliferative index (proliferating cell nuclear antigen), a factor associated with invasion (cathepsin D), and mutated tumor suppressor gene and proto-oncogene products (mutated p53, c-erbB-2). Four men who were seropositive for the human immunodeficiency virus and had acquired immunodeficiency syndrome presented with painful oral lesions of variable duration. Oral cancer risk factors included heavy tobacco use (four of four), heavy alcohol use (three of four), and previous radiotherapy (one of four). The lesions consisted of ulcers (two of four), a fungating mass (one of four), and papillary erythroplakia (one of four). Incisional biopsy specimens were obtained. High-stringency in situ hybridization was performed with DNA probes to the human papillomavirus (types 6/11; 16/18; 31/33/35) and Epstein-Barr virus: Immunocytochemical studies for the herpes simplex virus, proliferating cell nuclear antigen, cathepsin D, mutated p53, and c-erbB-2 were performed. Two lesions were moderately differentiated squamous cell carcinoma, one lesion was a basaloid squamous cell carcinoma, and one was carcinoma in situ. Stage of disease at diagnosis was II (one of four), III (two of four), and IV (one of four). Three cases were positive for the human papillomavirus, one case was positive for Epstein-Barr virus, and three cases were positive for the herpes simplex virus. C-erbB-2 was focally positive in one case, and mutated p53 was positive in a separate case.(ABSTRACT TRUNCATED AT 250 WORDS)

Cytoplasmic expression of p53 protein and its morphological features in salivary gland lesions

An immunohistochemical study of p53 protein was carried out on 45 salivary gland lesions using a monoclonal antibody, Bp53-12, raised to the intracellular domain of the p53 protein. p53 protein expression was found in 34.4% of 32 salivary gland carcinomas. Nuclear p53 expression was detected in tumor cells but not in non-neoplastic cells, except in one salivary duct carcinoma. The perinuclear cytoplasm of luminal duct cells was specifically positive for the antibody used here. Cytoplasmic p53 expression was observed mostly in non-neoplastic cells. There was a tendency for the cytoplasmic staining of p53 protein to be observed in the normal cells adjacent to p53-positive carcinomas, but none of the normal cells were positive in the tissues surrounding p53-negative carcinomas. Cytoplasmic expression of p53 protein in salivary gland tissues seems to be correlated with tumorigenesis.

Prognostic evaluation of HPV-associated precancerous and microinvasive carcinoma of the oral cavity: combined use of nucleolar organiser regions (AgNOR) and proliferating cell nuclear antigen (PCNA)

Nucleolar Organiser Regions (NORs) and Proliferating Cell Nuclear Antigen (PCNA) were investigated on routine paraffin embedded histologic sections of 30 oral biopsy specimens (six cases of leukoplakia with low-degree of dysplasia, nine cases of leukoplakia with moderate-degree of dysplasia, nine cases of leukoplakia with severe-degree of dysplasia, six cases of squamous microinvasive carcinomas), tested for HPV-DNA by in situ hybridisation (ISH). The absolute number of NORs per nucleus and the percentage of nuclear positivity for PCNA were found to be different in each group of pathology, with further diversity due to the presence or absence of HPV-DNA. In the major part of HPV-positive lesions, the AgNOR number and percentage of cells positive for PCNA were found to be generally lower than in corresponding negative forms. Conversely, a few cases of HPV+ lesions showed significantly higher values both of AgNOR and PCNA, if compared to the other cases of HPV+ and HPV- lesions. These data suggested that high values of AgNOR and PCNA, in moderate and high grade oral dysplasia, could represent an "alarm signal" of a worse prognosis, and then a possible indication for a strict clinical management and/or a stronger treatment of some HPV-associated preneoplastic lesions.

Oral precancer: preventive and medical approaches to management

Leukoplakias are among the most common potentially malignant oral lesions. Some are idiopathic, others are related to habits such as tobacco and/or alcohol use. Medical management includes reducing or abandoning these habits, increasing the intake of fruit and vegetables in the diet, and possibly the use of active agents. Retinoids, carotenoids and topical cytotoxic agents show promise, and newer therapies are on the horizon.

Heat shock protein expression in oral epithelial dysplasia and squamous cell carcinoma

Heat shock protein (HSP) expression is upregulated in tumour cells and, therefore, HSP expression is a likely marker of the malignant potential of oral epithelial lesions. Furthermore, the 70-kDa HSP (HSP 70) is implicated in the degree of tumour differentiation, the rate of tumour proliferation and the magnitude of the anti-tumour immune response. Accordingly, the distribution and intensity of HSP 70 expression was assessed in the epithelial compartment of oral squamous cell carcinoma (SCC, n = 29), dysplastic oral epithelium (n = 18) and benign oral mucosal lesions (n = 22) using avidin-biotin complex immunohistochemistry and microdensitometry under standardised conditions. Staining intensity was recorded in kilo-ohms (k omega). Normal oral mucosa (n = 15) was used for comparison, and results were analysed using Kruskall-Wallis and Fisher's exact tests. The distribution of HSP 70 expression in well differentiated SCC was significantly different from that in poorly differentiated SCC (P < 0.05), the latter demonstrating a more focal staining pattern. Median staining intensity in SCC (6.22 k omega), epithelial dysplasia (9.61 k omega) and the benign oral mucosal lesions (8.28 k omega) was significantly greater than that in normal oral mucosa (5.64 k omega; P < 0.05). Staining intensity in poorly differentiated SCC (7.66 k omega) was greater than that in moderately differentiated SCC (4.77 k omega), although this result just failed to reach statistical significance (P = 0.06). These results suggest that, as employed currently, HSP 70 expression is not a definitive marker of oral malignancy or malignant potential.(ABSTRACT TRUNCATED AT 250 WORDS)