Squamous Cell Carcinoma Of Oral Mucosa Research Articles

Germline mutations in patients with oral mucosal leukoplakia and squamous cell carcinoma: a prospective observational study

Background. The number of studies devoted to the molecular genetics of oral mucosal leukoplakia and squamous cell carcinoma is small, while the obtained results are usually preliminary in nature. We can assume the existence of region-specific pathogenic genetic variants involved in the development of oral mucosal leukoplakia and squamous cell carcinoma. With the knowledge of such variants, it would become possible to develop PCR (polymerase chain reaction) and NGS (next-generation sequencing) test systems for the detection of clinically significant germline mutations.Objectives — to identify pathogenic germline genetic variants in patients with oral mucosal leukoplakia accompanied by grade 1 epithelial dysplasia, as well as oral mucosal squamous cell carcinoma, using new-generation sequencing.Methods. Study design: prospective, observational, cross-sectional, without a control group. The sample included patients (48 persons) of either sex (18 years of age or older) with the following proven and morphologically confirmed diagnoses: oral mucosal leukoplakia accompanied by grade 1 squamous intraepithelial neoplasia of epithelium (24 people) and oral mucosal squamous cell carcinoma (24 people), who sought medical care at the Vitebsk Regional Clinical Dental Center and Vitebsk Regional Clinical Oncological Center in 2019–2020. The identified pathogenic and presumably pathogenic genetic variants involved in the development of these diseases were quantitatively assessed. The study was conducted at the Shareable Core Facilities GENOME of the Institute of Genetics and Cytology of the National Academy of Sciences of Belarus. In order to isolate deoxyribonucleic acid (DNA) from blood samples, a QIAamp DNA FFPE Tissue Kit (Qiagen, Germany) was used. The preparation of DNA libraries and sequencing were carried out by means of an Illumina NextSeq 550 sequencing system (Illumina, Inc., USA) using an Illumina Nextera DNA Exome kit (USA). Bioinformatic analysis was conducted using Illumina BaseSpace specialized software (USA) and Galaxy Project (Galaxy Community, an international non-profit project) in accordance with current guidelines. The obtained data were statistically processed employing specialized software packages Statistica 12 (StatSoft, Inc., USA) and MedCalc 18.9.1 (MedCalc Software, Ltd, Belgium).Results. Next-generation whole-exome sequencing of deoxyribonucleic acid samples isolated from the blood of patients with oral mucosal leukoplakia and squamous cell carcinoma has been conducted in the Republic of Belarus for the first time. The total number of unique germline genetic variants in the exome of both groups of patients was shown to be very high, yet most of them were not pathogenic. In the examined patients, the majority of germline mutations were found to be localized only in 19 exome genes: MAP2K3, DNAH5, HSPG2, OBSCN, SYNE1, HLA-DRB1, HLA-DQA1, HLA-DQB1, HLA-A, HLA-B, PKD1L2, TTN, AHNAK2, PDE4DIP, MUC3A, MUC4, MUC12, MUC16, and MUC17. In both clinical groups, the greatest number of genetic variants (> 40% of the total number) was detected in MUC3A, MUC4, MUC12, and MUC16, responsible for the synthesis of the glycoprotein mucin family.Conclusion. Oral mucosal leukoplakia and squamous cell carcinoma can arise from the pathogenic variants of MUC3A, MUC4, MUC12, and MUC16.

A Spectacular Response to the Docetaxel Cisplatin Fluorouracil (TPF) Protocol as Induction Chemotherapy in Locally Advanced Squamous Cell Carcinoma of the Lower Lip: A Case Report

Background: Oral-mucosal squamous cell carcinoma (omSCC) is a substantially more aggressive disease that affects the oral mucosa, tongue, floor of mouth, and oropharynx, where it is estimated that between 18.6% and 44% of patients present with nodal disease depending on the subsite. As the lip is a site of anatomical overlap, primary squamous cell carcinoma of the lip (lip SCC) exhibits higher rates of nodal spread, mortality, and poor clinical outcome compared with cutaneous SCC. For patients with locally advanced OSCC, rapid advancements regarding the choice of induction chemotherapy regimen have been made. There is substantial evidence related to the advantage and superiority of three-drug combination of Docetaxel, Cisplatin, and Fluorouracil (TPF) over the doublet regime of Cisplatin and Fluorouracil (PF) used previously as induction chemotherapy (ICT). Case presentation: A 54 years Moroccan women old, who has been accusing, for more than a year, of a neglected painful tumefaction of the lower lip. The clinical examination finds a budding and ulcerous tumefaction of the lower lip and a biopsy of his lip lesion was scheduled. Histopathology report poorly differentiated squamous cell carcinoma. Assessment of extension showed bilateral cervical lymphadenopathy and no distant locations. After a multidisciplinary discussion, the decision was to propose a conservative treatment, namely concurrent radio chemotherapy after induction chemotherapy made of the TPF protocol. The evaluation after 03 cycles of the protocol shows an almost complete disappearance of the apparent tumor with a good tolerance profile. Conclusion: Many analysis demonstrate a statistically significant reduction in locoregional recurrence amongst patients who received Induction chemotherpay despite that she has never provided an improvement to OS for OSCC patients. In the present case, chemotherapy with docetaxel, cisplatin and fluorouracil regimens is considered as an effective induction therapy ...

Osteoradionecrosis After Radiation to Reconstructed Mandible With Titanium Plate and Osseointegrated Dental Implants

A 68-year-old man with no history of smoking and no notable comorbidities presented to the hospital with a newly diagnosed T4aN2aM0 oral mucosal squamous cell carcinoma (SCC) invading the periosteum and body of the left mandible. He subsequently underwent tracheostomy, radical resection, segmental mandibulectomy, selective neck dissection, and reconstruction with a 3-segment, double-barrel osteocutaneous free fibula flap with immediate placement of 3 osseointegrated dental implants for ease of future dental reconstructions (Fig 1A).

PD-L1 and survival in oral cavity squamous cell carcinoma

Relevance. Prognostic value of PD-L1 expression in oral cavity squamous cell carcinoma (OCSCC) and its effect on survival is still controversial. It should be to determine the prognostic role of PD-L1 expression on tumor and immune cells of OCSCC and assess their effect on overall survival (OS) and progression-free survival (PFS).Materials and methods. A prospective study included 145 patients, first diagnosed with OCSCC. PD-L1 expression on tumor and immune cells, infiltrating tumor and its microenvironment, was assessed in all tumor samples by IHC, CPS was calculated. Cut-off values were determined by ROC analysis for identification of PD-L1 expression effect on OS and PFS.Results. Most patients with oral mucosa squamous cell carcinoma showed positive expression of PD-L1 on tumor (77.2%) and immune cells (92.4%). The median PD-L1 expression on tumor cells was 13.5% [1.0-40.0], the median PD-L1 expression on immune cells was 5.0% [1.0-11.0], and the median CPS – 18.0 [3.0-7.8]. Univariate and multivariate analyses revealed a significant negative effect of PD-L1 expression on immune cells ≤ 7% on OS (HR 0.66; 95% CI 0.45-0.93; p = 0.0498); PD-L1 expression in tumor cells ≤ 15% (HR 0.65; 95% CI 0.43-0.98; p = 0.0416) and CPS ≤ 21 (HR 0.62; 95% CI 0.44-0.92; p = 0.0183) for PFS. PD-L1 expression in tumor cells ≤ 6% (HR 0.71; 95% CI 0.47-1.08; p = 0.1096) and CPS ≤ 7 (RR 0.67; 95% CI 0.44-1.01; p = 0.0575) had a confident tendency to negative impact on OS.Conclusion. Positive PD-L1 expression in tumor and immune cells as well as CPS are effective additional factors in the prognosis of the disease course, OS and PFS in patients with OCSCC.

Setting of the surgical margin using optical instrument for treatment of early tongue squamous cell carcinoma

ObjectiveReveal the usefulness of loss of fluorescence visualization in the determination of surgical margin in early tongue oral squamous cell carcinoma (SCC). BackgroundSCC is often surrounded by oral epithelial dysplasia (OED), which can result in local recurrence. An optical instrument can be used to detect OED and SCC in oral mucosa, but whether it affects the prognosis after SCC surgery is unknown. Since 2010, we have performed visual examinations for fluorescence visualization loss at the Department of Oral and Maxillofacial Surgery, Tokyo Dental College in Chiba Hospital. The aim of this study was to clarify the usefulness of an optical instrument for treating early tongue SCC. Patients and methodsA total of 272 patients with primary T1-2N0 tongue SCC who underwent surgery between 1982 and 2016 at our hospital were selected. The surgical margin was at least 7 mm from the margin of fluorescence visualization loss. Outcomes were retrospectively investigated. ResultsAfter introduction of the optical instrument, 5-year overall survival and the local control rate were 93.9% and 97.1%, respectively (p = 0.440, p = 0.045). In all periods, the optical instrument group achieved a favorable prognosis. On intraoperative frozen section examination (including OED), the positive rate was 19.0% (p = 0.028). The positive rate of a pathological history in OED and SCC was 12.3% and 0% (p = 0.021, p < 0.001), respectively. ConclusionsThe optical instrument group achieved favorable results. This suggests that fluorescence visualization loss observed with an optical instrument is useful for deciding the surgical margin in early tongue SCC.

Squamous Cell Carcinoma of the Lip-A Review of Squamous Cell Carcinogenesis of the Mucosal and Cutaneous Junction.

The lip is an anatomic junction for 2 disparate groups of cancer. Cutaneous squamous cell carcinoma (cSCC) is a common malignancy with a favorable prognosis, whereas oral-mucosal squamous cell carcinoma (omSCC) is associated with significantly higher rates of nodal disease and worse outcomes. The squamous cell carcinoma of the lip (lip SCC) is more aggressive than cSCC but less aggressive than omSCC. However, work-up and treatment vary between specialties. The authors sought to review and compare the risk factors and clinical behavior of cSCC, omSCC, and lip SCC, review tumor biology of squamous cell carcinoma, and compare work-up and treatment algorithms for lip SCC. A comprehensive PubMed and MEDLINE database search was performed with comparison of primary literature on cSCC, omSCC, and lip SCC. Lip SCC exhibits rates of nodal metastasis and death that are intermediate between cSCC and omSCC, and shares many similar biologic mechanisms. There are variations in the treatment guidelines between dermatology and otolaryngology for lip SCC. Lip SCC is an overlapping entity that poses many challenges to clinicians. Specialists should be aware of current staging modalities as well as imaging and treatment recommendations to optimize patient outcomes.

Evaluation of capability of ultrasound with elastometry and elastography for diagnosis of subclinical regional metastases of cancer of the oral mucosa

Objective. Evaluation of ultrasound capabilities for diagnosis of subclinical regional metastases of squamous cell carcinoma of the oral mucosa. Introduction. Incidence of oral cancer in Russia is 3.86 per 100,000 population, and it’s increasing with the mean annual rate of 1.88 %. Head and neck cancer is characterized by high risk of metastases in regional lymph nodes which varies from 40 to 80 %. Lymph nodes status affects the treatment plan and appears to be the main predictive factor. Therefore, evaluation of the pathways of regional lymphatic outflow in oral mucosa cancer is of prime importance for disease prognosis and treatment selection. Ultrasound investigation (USI) is one of the main instrumental methods of regional lymph node investigation in oral mucosa cancer patients. Nevertheless, effectiveness of B-mode USI, elastometry and elastography for diagnosis of occult metastases of squamous cell carcinoma of the oral mucosa has not been investigated. There is no consensus on the threshold values of S-wave velocity and elastographic parameters in diagnosis of occult metastases. Materials and methods . Patients with oral mucosa squamous cell carcinoma (stage cT1–3N0M0) were included in the study. All patients had morphologically verified diagnosis. At the first stage (outpatient) before inclusion into the study, all patients were evaluated by palpation and B-mode USI. If during USI metastases were suspected, FNAB was performed. Patients with cytologically confirmed metastases were not eligible for the study. During the clinical trial, 102 (82.3 %) patients underwent B-mode USI, and 22 (17.7 %) patients underwent USI with elastometry and elastography. USI results were compared with results of histological examination of cervical lymph nodes. Statistical evaluation of USI in different modes was performed. Results. B-mode USI was characterized by 88.2 % specificity, 0 % sensitivity, 80.4 % accuracy, and 44.1 % efficacy. Positive predictive value (PPV) was estimated as 0 %, and negative predictive value (NPV) as 90.1 %. USI with elastography was characterized by 100 % specificity, 83.3 % sensitivity, 95.5 % accuracy, and 91.7 % efficacy. PPV was estimated as 100 %, and NPV as 94.1 %. Threshold value of elastometry for diagnosis of occult metastases was 2.42 m/s with 83.3 sensitivity, and 87.5 % specificity. Method was characterized by 86.4 % accuracy, 85.4 efficacy, 71.4 % PPV and 93.3 % NPV. Conclusion . B-mode USI is characterized by low capability for diagnosis of subclinical regional metastases of squamous cell carcinoma of the oral mucosa. Elastometry and elastography offer a possibility to increase USI accuracy for diagnosis of subclinical regional metastases from 80 % to 86-95.5 % and efficacy from 44 % to 85–92 %.

SOBREVIDA EN CARCINOMA ESPINOCELULAR DE MUCOSA ORAL: ANÁLISIS DE 161 PACIENTES

survival in oral mucosa squamous cell carcinoma. analysis of 161 patients introduction: Oral Cancer accounts 3% of all human cancers. Squamous Cell Carcinoma is the most common. nowadays, in Chile and the world, oral cancer is reaching relevance because of its high inciden - ce and low survival rates; most often is squamous cell carcinoma (SCC). aim: We analyzed the five-year survival of 161 patients diagnosed with SCC. Also was studied relationships between survival and gender, age, location, tobacco, alcohol and treatment. methods: Retrospective study among 1989 and 2010. The study population was mainly men gender (59%), average age 64 years and location of the CEC prefera- bly in tongue (37.6%). 54% were well differentiated carcinomas and TnM, the majority corresponding to T2n0M0. Kaplan-Meier curve and Log Rank test were used for survival analysis and to compare them. We determined significant difference when p value < 0.05. results: The overall survival at five years was 46%, the lowest rates were in the male gender, age group 60, floor of mouth, smokers and alcohol consumers. conclusions: Although tobacco and alcohol are factors highly related to the presence of CEC, there was no significant difference between survival and these habits. There were differences between the survival curves for patients treated with surgery associated with radiotherapy in comparison to other treatments.

Comparison of the AJCC N staging system in mucosal and cutaneous squamous head and neck cancer

The American Joint Committee on Cancer (AJCC) substantially changed the staging of cutaneous squamous cell carcinoma (cSCC) in the seventh edition of its staging manual. Given that oral mucosal squamous cell carcinoma (mSCC) and cSCC behave differently and affect different patient populations, the aim of this study was to provide a side-by-side comparison and to evaluate the current nodal (N) grouping for cSCC alongside oral mSCC to determine whether the same system is justified. Retrospective analysis of prospectively collected data. Multivariable analysis of 672 patients with metastatic cSCC and of 225 patients with metastatic mSCC from two prospective cancer-center databases. While, as expected, the N grouping functioned well in mSCC in terms of distribution and stratification of patients, it performed much less favorably in cSCC. In contrast to mSCC, the different N groups demonstrate much less prognostic importance in cSCC. Although the introduction of a unified N system for mSCC and cSCC has definite advantages, it does not translate into optimal distribution and stratification for metastatic cSCC. 4.

The Value of 99mTc-MDP SPECT/CT Fusion Imaging in Evaluating the Extent of Mandibular Invasion by Squamous Cell Carcinoma of Oral Cavity

Objective: Comparing the Accuracy of computed tomography (CT) and 99mTc-methylene-diphosphonate (MDP) SPECT/CT fusion imaging in determining the extent of mandibular invasion by squamous cell carcinoma of the oral cavity, to study the clinical value of SPECT/CT fusion imaging in evaluating the extent of mandibular invasion by squamous cell carcinoma of oral cavity. Material and Methods: Fifty-one patients were revealed mandibular invasion by moderately differentiated squamous cell carcinoma of the oral cavity underwent CT and SPECT/CT. The patients were divided into two groups: A group (oral mucosal squamous cell carcinoma) and B group (primary intra-osseous carcinoma). Two radiologists assessed the CT images and two nuclear medicine physicians separately assessed the SPECT/CT images in consensus and without knowledge of the results of other imaging tests. The extent of bone involvement suggested with an imaging modality was compared with pathological findings in the surgical specimen. Results: The pathological findings as the reference standard ,group A:the extent of mandibular invasion by moderately differentiated squamous cell carcinoma underwent SPECT/CT was 1.02±0.20cm lager than the pathological examination identified, and the extent of mandibular invasion underwent CT was Advances in Cancer: Research & Treatment 2 1.42±0.35cm smaller than the pathological examination identified. There were statistically significant differences among the three methods, p<0.01. Group B: the extent of mandibular invasion by moderately differentiated squamous cell carcinoma underwent SPECT/CT was 1.3±0.39cm larger than that underwent pathological examination. The extent of mandibular invasion underwent CT was 2.55±1.44cm smaller than the pathological examination identified. There were statistically significant difference among the three methods (p<0.01), too. Conclusion: SPECT/CT fusion imaging in identifying the extent of squamous cell carcinoma of the oral cavity on mandibular invasion has important clinical value. The extent of mandibular invasion underwent SPECT/CT was the extent which surgeon to reach the clear margins to the limits of resection.

Clinicopathological study of SIN at the surgical margin after partial glossectomy for primary SCC

Clinical management and histopatholocial conservations of epithelial dysplasia at the surgical margin at the time or after glossectomy for oral mucosal squamous cell carcinoma has been retrospectively discussed. The subjects were 34 patients with T1/T2 primary squamous cell carcinoma of the tongue who had undergone resection without pre-operative treatment in our hospital, for 10 years, between January 1995 and June 2006. Histopathological evaluations and prognosis were assessed according to squamous intraepithelial neoplasia (SIN) classification designed by the Japan Society of Oral Tumours Committee and the Working Group for Guideline of Tongue Cancer Treatment.

Importance of tumor thickness and depth of invasion in nodal involvement and prognosis of oral squamous cell carcinoma: A review of the literature

Oral mucosa squamous cell carcinoma (OSCC) has locoregional evolution, with frequent neck involvement (the most important parameter for prognosis). There are still many doubts concerning the best way to approach N0 neck disease in early-stage lesions (T1 and T2). Many parameters have been studied to identify N0 patients with a high likelihood of harboring occult node metastases or of having them develop. A review of the studies analyzing "tumor thickness"/"depth of invasion" in predicting regional metastases and survival was undertaken. The literature suggests that "tumor thickness"/"depth of invasion" is a reliable parameter for predicting regional nodal involvement and survival in OSCC. Authors are in substantial agreement regarding the reliability of tumor thickness. The lack of comparable study groups, measurement techniques, and cut-off values points to the need for further studies so as to reach a consensus and to develop therapy protocols that include tumor thickness.

Clinical significance and surgical management of regional lymph nodes in oral cancers - a review of English literature up till July 2001

Regional lymph node metastases is found in about 6-85 per cent of all patient with carcinoma in the head and neck region. It is also widely accepted that lymph node metastases is the single most important predictor of survival in patient with squamous cell carcinoma of the oral cavity. The present review was undertaken to provide practitioners managing oral cancers in the sub-region an update on developments in the clinical significance and management of regional lymph node metastases in oral mucosa squamous cell carcinoma. This review is primarily based on articles selected from MEDLINE concerning regional lymph nodes metastases of oral squamous cell carcinoma up to July 2001. Characteristics of metastatic lymph node such as number of positive nodes, histological features, extracapsular spread and location in the neck significantly affect the prognosis of oral squamous cell carcinoma in individual patient more that most other parameters that are usually considered in the surgical management of such lesion. Prognosis of oral mucosa squamous cell carcinoma to a large extent depend on the status of regional lymph nodes however, the management of such node varies in different center. Conservative approach such as supraomohyoid neck dissection is currently widely accepted as the method of management in No and some selected N1 neck in oral squamous cell carcinoma.

Odontogenic carcinoma: a functional genomic comparison with oral mucosal squamous cell carcinoma

Intraosseous squamous cell carcinomas of the mandible arise de novo or secondary to a tumor or transformed cyst epithelium. Current diagnostic tests frequently fail to distinguish between these tumors, leading to confusing classification schemes. We report the functional genomic analysis of a mandibular odontogenic carcinoma. Malignant keratinocytes from the lesion were isolated using laser capture microdissection. Target sample generated from the total RNA of the LCM-procured cells was used to hybridize high-density oligonucleotide arrays. Functional genomic analysis of the odontogenic carcinoma database compared with four oral mucosal squamous cell carcinoma gene expression databases was performed. Preliminary results suggest a small subset of genes distinguish this odontogenic carcinoma from oral mucosal epidermoid carcinomas.

Expression of integrin alpha9 subunit and tenascin in oral leukoplakia, lichen planus, and squamous cell carcinoma.

Integrin alpha9 subunit is a member of beta1 integrin family and binds tenascin (TN). It is expressed by stratified squamous epithelium and may be associated with cell differentiation and growth. We studied if the expression of alpha9 integrin and TN is altered in leukoplakia, lichen planus, and squamous cell carcinoma (SCC). Frozen sections of tissue samples obtained from normal human keratinized (16 subjects) and non-keratinized (three subjects) oral mucosa, oral leukopakias with dysplasia (19 subjects), reticular type lichen planus (nine subjects), or oral mucosal SCC (23 subjects) were stained immunohistochemically with antibodies against alpha9 integrin and TN. In contrast to its most prominent localization at the cell membranes of the basal epithelial cells in the normal mucosa, alpha9 integrin was localized in a more diffuse pattern with focal loss of expression at the epithelial cell membranes in leukoplakic dysplasia, lichen planus, and SCC. In some areas of SCC, alpha9 integrin localized throughout all cell layers of the tumor epithelium. In most areas, alpha9 integrin colocalized with TN but in heavily inflamed areas there was focal loss of TN and alpha9 integrin at the basement membrane zone. The findings show that alpha9 integrin expression is altered in leukoplakic dysplasia, lichen planus, and SCC.

Oral squamous cell carcinoma in a young person with candidosis endocrinopathy syndrome: a case report

Candidosis endocrinopathy syndrome is a rare condition characterized by mucocutaneous candidosis and multiple endocrinal abnormalities. This case reports a patient with the syndrome who also developed an oral mucosal squamous cell carcinoma at the age of 21.

Detailed topography of cervical lymph-node metastases from oral squamous cell carcinoma

The histologic presence and detailed topography of cervical lymphnode metastatic tumours was investigated in a series of neck dissections from 154 previously untreated patients with oral mucosal squamous cell carcinoma. Metastasis was evident in 73 patients (47%), including 13 (8%) with bilateral spread and 14 (9%) with only micrometastases. Multiple positive nodes were recovered from 58 (67%) of the 86 positive sides of neck dissection, and fusion of nodes was seen in 22 dissections (26%). Both direct extracapsular and embolic spread accounted for advanced disease. An orderly progressive (“overflow”) involvement of anatomic levels was seen in 85% of positive dissections. “Skipping” of anatomic levels II and/or III was seen in 10%, and “peppering” of nodes at multiple levels without any macroscopic focus in 5%. Hence, “fast-tracks” may account for the distribution of metastatic carcinoma in 15% of positive necks. Adjuvant radiotherapy was dependent on the pathologic stage. The range of postoperative follow-up was 1–6 years. Death from recurrent regional disease occurred only in patients who had exhibited macroscopic or microscopic extracapsular spread. Survival was similar (75%) for patients with either macroscopic or microscopic metastases confined to lymph nodes or no evidence of metastasis. Hence, with surgery and adjuvant radiotherapy, metastases confined to lymph nodes do not appear to affect the short-term prognosis.

Induction by 4‐nitroquinoline‐l‐oxide of oral epithelial dysplasia and neoplasia in scurvy‐prone osteogenic disorder shionogi (ODS) rats

Carcinogenesis by 4-nitroquinoline-1-oxide (NQO) in the oral mucosa is a reliable method of obtaining oral mucosal squamous cell carcinoma (OMSCC) and allows examination of various stages of oral cancer development. In vivo and in vitro studies have indicated that L-ascorbic acid (AA) may have a role in cancer prevention. The Wistar "scurvy-prone" osteogenic disorder Shionogi (ODS) rat of the od/od substrain is unable to synthesize AA and requires supplementation for its survival. This study examined the effects of NQO on the oral mucosa of ODS and outbred Wistar rats. NQO (0.5%) was applied topically to the palatal mucosa of 72 male ODS and 36 outbred Wistar rats three times weekly for 4, 8, 12, 16, 20, and 24 wks. The ODS rats were divided so that 36 rats were given 2.5 g/l AA in the drinking water and 36 rats were given 0.33 g/l AA. Vehicle-treated and untreated control animals were included. The rats were killed two weeks after the final NQO application, and the tissues were examined. Epithelial dysplasia was assessed using a modified Smith and Pindborg (1969) index. The ordered categorical scores were analyzed appropriately. Plasma AA levels were checked in ODS and outbred rats at the start and end of the experiment. The results indicated that the oral mucosa of the ODS and outbred rats were susceptible to NQO but that the rate of dysplasia and OMSCC development differed between them, with more rapid changes being found in the ODS rats (p < or = 0.05). No significant difference was found in the dysplasia scores and in the rate of OMSCC development between ODS rats given 2.5 g/l of AA and ODS rats given 0.33 g/l of AA (p > 0.05). No epithelial changes were observed in the palatal mucosa of vehicle-treated and untreated controls. The plasma AA level mean (+/- SEM) was 56 +/- 6 microM for the outbred rats, 8 +/- 1 microM for the ODS rats given 0.33 g/l AA supplementation, and 29 +/- 2 microM for the ODS rats given 2.5 g/l AA. It was concluded that the chronic AA-deficient state in ODS rats played an insignificant role in oral carcinogenesis and that other factors, for example, genetic differences in susceptibility to NQO, contributed to the present findings.

The expression of c-erbB-2 protein in the keratinocytes of oral mucosal lichen planus.

The expression of the c-erbB-2 protein was studied in the keratinocytes from patients with: (i) oral mucosal lichen planus (OLP) (n = 26); (ii) oral mucosal squamous cell carcinoma (OMSCC) which had arisen in mucosa affected by OLP (n = 5); and (iii) normal oral mucosa (n = 5). C-erbB-2 protein was expressed on the cell membranes of the keratinocytes of nucleated epithelium in the stratum spinosum. The antigenic determinant recognized represents the cytoplasmic domain of a cell surface receptor which binds an as yet uncharacterized heparin binding ligand of unknown function. The specimens from the five normal subjects showed positive immunohistochemical staining with the monoclonal c-erbB-2 protein antibody, the OMSCC specimens were negative, and 23 of 26 of the OLP specimens were positive. The lack of c-erbB-2 expression in the three OLP and in the five OMSCC specimens may indicate a genetic alteration, or masking of the expression of c-erbB-2. The absence of expression in OLP specimens might be an indicator of the possibility of future neoplastic transformation.

Binding pattern of eight different lectins in healthy subjects and patients with dysplastic and malignant lesions of the oral cavity

The present investigation was undertaken to assess the binding characteristics of eight different lectins to normal oral mucosa (11 cases), leukoplakia with varying degrees of dysplasia (five cases), and oral mucosal squamous cell carcinoma (12 cases) by the use of biotinylated lectins and avidin biotin peroxidase complexes. The lectins employed were soybean (SBA), peanut (PNA), Dolichos biflorus (DBA), concanavalin A (Con A), wheat germ (WGA), Ulex europaeus (UEA), Ricinus communis (RCA), and Lotus tetragonolobus (LTA). It was observed that SBA, DBA, WGA, UEA, RCA, and LTA showed very strong to strong binding in healthy oral mucosa but no or very weak binding in squamous cell carcinoma. On the contrary, PNA showed weak binding to normal mucosal epithelial cells but showed strong binding to malignant cells. The dysplastic mucosa had an intermediate binding pattern. The lectin Con A was not bound at all or seen in very low concentration in the malignant cells and dysplastic epithelium, but it showed weak binding in the normal mucosa. Hence, we conclude that lectins may be utilized as probes to determine the dysplastic and malignant status of the oral mucosal epithelium.