Downregulation of Notch4 - a prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma / Regulação descendente de Notch4 - um marcador prognóstico na distinção entre carcinoma verrucoso oral e carcinoma de células escamosas oral

Abstract Introduction: Oral verrucous carcinoma is a special form of well-differentiated squamous cell carcinoma which possesses specific clinical, morphologic and cytokinetic features that differ from other types of oral cancers and hence diagnosis requires immense experience in histopathology. Hence it is certainly important to distinguish such a lesion from other oral tumors as treatment strategies vary widely between them. Objective: In search of a critical diagnostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma, Notch4 receptor, one of the key regulatory molecules of the Notch signaling family has been aberrantly activated in the progression of several types of tumors. However its function in oral verrucous carcinoma remains unexplored. Thus the present study aims in determining the differential expression pattern of Notch4 in oral verrucous carcinoma and oral squamous cell carcinoma. Methods: Ten patients reported positive for oral cancer (5 patients with oral verrucous carcinoma and 5 patients with oral squamous cell carcinoma). Five normal tissue samples were also obtained and evaluated for clinicopathological parameters and immunohistochemistry, western blotting and real time polymerase chain reaction for Notch4 expression. Results: Our results reveal that the expression of Notch4 was considerably high in oral squamous cell carcinoma lesions compared to normal tissue, whereas in oral verrucous carcinoma, irrespective of the clinicopathological features, complete regulação descendente of Notch4 was observed. Conclusions: These preliminary findings strongly support the fact that Notch4 is downregulated in oral verrucous carcinoma and could be considered as a suitable prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma. This distinguishing marker can help in improving therapeutic options in patients diagnosed with oral verrucous carcinoma.

Resumo Introdução: O carcinoma verrucoso de cavidade oral é uma forma especial de carcinoma de células escamosas bem diferenciada que tem características clínicas, morfológicas e citocinéticas específicas que diferem de outros tipos de cânceres orais. Por essa razão, o diagnóstico requer grande experiência em histopatologia. Portanto, é certamente importante distingui-lo de outros tumores orais, pois as respectivas estratégias de tratamento variam muito. Objetivo: Em busca de um marcador de diagnóstico crítico na distinção entre o carcinoma verrucoso e o carcinoma de células escamosas de cavidade oral, o receptor Notch4, uma das principais moléculas reguladoras da família de sinalizadores Notch, foi ativado de maneira anormal na progressão de vários tipos de tumores. No entanto, sua função no carcinoma verrucoso permanece inexplorada. Assim, o presente estudo tem como objetivo determinar o padrão de expressão diferencial de Notch4 no carcinoma verrucoso e de células escamosas de cavidade oral. Método: Dez pacientes tiveram resultado positivo para câncer oral (cinco pacientes com carcinoma verrucoso e cinco pacientes com carcinoma de células escamosas) e cinco amostras normais foram também obtidas. Além da avaliação dos parâmetros clínico-patológicos, foram feitos análise imuno-histoquímica, Western Blot e reação de polimerase em cadeia em tempo real para a expressão de Notch4. Resultados: Nossos resultados revelam que a expressão de Notch4 foi consideravelmente alta em carcinomas de células escamosas em comparação com os tecidos normais, enquanto que no carcinoma verrucoso, independentemente das características clínico-patológicas, observou-se regulação descendente completa de Notch4. Conclusão: Esses achados preliminares apoiam fortemente o fato de que Notch4 estava regulado para baixo no carcinoma verrucoso oral e poderia ser considerado um marcador prognóstico adequado para distinguir entre carcinoma verrucoso e carcinoma de células escamosas de cavidade oral. Esse marcador distintivo pode ajudar a melhorar as opções terapêuticas em pacientes com diagnóstico de carcinoma verrucoso oral.

Downregulation of Notch4 - a prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma.

INTRODUCTION: Oral verrucous carcinoma is a special form of well-differentiated squamous cell carcinoma which possesses specific clinical, morphologic and cytokinetic features that differ from other types of oral cancers and hence diagnosis requires immense experience in histopathology. Hence it is certainly important to distinguish such a lesion from other oral tumors as treatment strategies vary widely between them. OBJECTIVE: In search of a critical diagnostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma, Notch4 receptor, one of the key regulatory molecules of the Notch signaling family has been aberrantly activated in the progression of several types of tumors. However its function in oral verrucous carcinoma remains unexplored. Thus the present study aims in determining the differential expression pattern of Notch4 in oral verrucous carcinoma and oral squamous cell carcinoma. METHODS: Ten patients reported positive for oral cancer (5 patients with oral verrucous carcinoma and 5 patients with oral squamous cell carcinoma). Five normal tissue samples were also obtained and evaluated for clinicopathological parameters and immunohistochemistry, western blotting and real time polymerase chain reaction for Notch4 expression. RESULTS: Our results reveal that the expression of Notch4 was considerably high in oral squamous cell carcinoma lesions compared to normal tissue, whereas in oral verrucous carcinoma, irrespective of the clinicopathological features, complete regulação descendente of Notch4 was observed. CONCLUSIONS: These preliminary findings strongly support the fact that Notch4 is downregulated in oral verrucous carcinoma and could be considered as a suitable prognostic marker in distinguishing oral verrucous carcinoma from oral squamous cell carcinoma. This distinguishing marker can help in improving therapeutic options in patients diagnosed with oral verrucous carcinoma.

Expression of Matrix Metalloproteinase-10 at Invasive Front of Squamous Cell Carcinoma and Verrucous Carcinoma in the Oral Cavity.

BACKGROUND: Matrix metalloproteinases (MMPs) are a family of zinc metalloproteinases capable of degrading components of connective tissues. MMP-10 is frequently expressed in human cancers. The aim of this study was to immunohistochemically evaluate its expression in oral squamous cell carcinoma (OSCC) and verrucous carcinoma (OVC). MATERIALS AND METHODS: A retrospective analysis of 73 samples (31 OSCC, 22 OVC and 20 non-neoplastic epithelium) was performed. All samples were immunohistochemically stained with monoclonal MMP-10 antibody and expression levels and staining intensity were evaluated with respect to microscopic features. Data were analyzed by SPSS (V.21), Mann-Whitney and Kruskal Wallis tests. RESULTS: MMP-10 was detected in all OSCC and OVC cases. The expression of MMP-10 in OSCC was intensive (score 3) and in OVC was low and moderate (score 1 and score 2) more frequently. Non- neoplastic epithelium did not show MMP-10 expression. Differences between groups was statistically significant (p<0.05). However, the expression of MMP- 10 was not obviously different between various grades of OSCC. CONCLUSIONS: According to our study, MMP-10 protein can be important possible factor in the transformation of normal oral epithelium to OVC and OSCC, also the level of MMP-10 expression at invasion front of the lesions can be helpful in the differentiation of OVC and OSCC.

Squamous cell carcinoma arising within verrucous carcinoma of the oral cavity: a case report.

The author herein reports a case of squamous cell carcinoma (SCC) arising within verrucous carcinoma (VC) of the hard palate. An 84-year-old woman was admitted to our hospital complaining of oral discomfort. Oral examination revealed a pedunculated verrucous tumor (15 x 15 mm) in the hard palate. A biopsy revealed verrucous tumor. Resection of the lesion with wide margins was performed. Grossly, the palate tumor was pedunculated and verrucous, but a depressed area (8 x 7 mm) was recognized. Microscopically, the verrucous ares showed verrucous proliferation of squamous epithelium with little cellular atypia, and was interpreted as VC without invasion. The depressed lesion was obvious SCC with invasion. There were direct transitions between the VC and SCC. Immunohistochemically, the VC and SCC tumor cells were negative for human papilloma virus antigens. P53 protein was expressed in both VC and SCC, though the expression in SCC was much more strong and broad than that in VC. The Ki-67 antigen was also expressed in the VC and SCC, and Ki-67 labeling index ranged was 12% in VC and 64% in SCC. These findings indicate that SCC may arise within VC.

Human papillomavirus detection in dysplastic and malignant oral verrucous lesions.

The role of human papillomaviruses (HPV) in dysplastic and malignant oral verrucous lesions is controversial since there is a wide range in the incidence of virus detection. This study used a multi-tiered method of HPV detection using DNA in-situ hybridisation (ISH) for low- and high-risk subtypes, consensus PCR, and HPV genotype analysis in archival tissue from 20 cases of dysplastic and malignant oral verrucous lesions. The biological significance of HPV DNA detection was assessed by p16 immunohistochemistry (IHC). While 1/7 carcinomas and 5/13 dysplasias contained HPV DNA by consensus PCR and genotype analysis, all specimens were negative for low- and high-risk HPV ISH and negative for p16 IHC. Results show that although high-risk HPV DNA is detectable in a subset of these lesions, the lack of p16 overexpression suggests that the oncogenic process is not driven by HPV oncoproteins.

Noninvasive squamous lesions in the urinary bladder: a clinicopathologic analysis of 29 cases.

Noninvasive squamous lesions are distinctively uncommon in biopsies of the urinary bladder with the exception of nonkeratinizing squamous metaplasia. The clinical significance of these squamous lesions in the bladder remains to be explored. A total of 29 cases of transurethral biopsies and resections of the bladder containing noninvasive squamous lesions (excluding nonkeratinizing metaplasia) were studied from the consult files of one of the authors. These cases included keratinizing squamous metaplasia (5), verrucous squamous hyperplasia (5), squamous papilloma (5), condyloma acuminatum (3), and squamous cell carcinoma in situ (CIS) (11). Immunohistochemistry for epithelial growth factor receptor (EGFR) and in situ hybridization for wide-range human papillomavirus was performed on 23 cases. The follow-up period ranged from 2 months to 3 years with an average of 1.5 years. After the initial diagnoses in biopsies of the bladder, 10 patients received cystectomies, and 7 patients received repeat tissue sampling of the bladder. Of the 5 patients with keratinizing squamous metaplasia, 2 patients had invasive urothelial carcinoma with squamous features in their cystectomy specimens at intervals of 3 and 14 months, respectively, 1 had persistent keratinizing squamous metaplasia on rebiopsy. Of the 5 patients with verrucous squamous hyperplasia, 1 patient had invasive squamous cell carcinoma at cystectomy at an interval of 14 months, 1 had squamous cell CIS on rebiopsy, 1 had persistent verrucous squamous hyperplasia on rebiopsy, and 2 had no evidence of disease at 6 and 24 months. Of the 5 patients with squamous papilloma, 1 patient had low-grade urothelial carcinoma at cystectomy at an interval of 21 months (h/o low-grade urothelial carcinoma preceding papilloma diagnosis), 2 were free of lesions at rebiopsy. Of the 3 patients with condyloma acuminatum, 1 had squamous CIS at cystectomy at an interval of 3 months, 1 had invasive squamous cell carcinoma at 20 months. Of the 11 patients with squamous cell carcinoma in situ (CIS), 3 patients had invasive squamous cell carcinoma at intervals of 2, 3, and 4 months, respectively, 1 had invasive urothelial carcinoma with squamous features in cystectomies at an interval of 12 months, 1 had squamous cell CIS at 10 months, 1 had high-grade urothelial carcinoma (not otherwise specified) at rebiopsy at an interval of 6 months, and 1 had no evidence of disease at 8 months. Among the 9 patients with invasive carcinoma, 4 patients died in the period of 0.5 to 3 years after the diagnoses. Immunohistochemical study with EGFR demonstrated strong signals in 20 cases and no signals in 2 cases. Wide-range human papillomavirus DNA signal was detected in 1 case of condyloma acuminatum and 1 case of squamous cell CIS. Keratinizing squamous metaplasia, verrucous squamous hyperplasia, and condyloma acuminatum in the urinary bladder can be associated with subsequent or concurrent in situ, or invasive squamous carcinoma and should be closely followed. Squamous cell CIS in the urinary bladder is often associated with subsequent or concurrent invasive carcinoma with squamous differentiation. Enhanced expression of EGFR in these bladder squamous lesions suggests that EGFR may represent a logic therapeutic target in those squamous lesions that are difficult to manage clinically.

Verrucous carcinoma of the axilla: case report and review.

BACKGROUND: Verrucous carcinoma, a variant of squamous cell carcinoma, is distinct from squamous cell carcinoma in morphology and behavior. It preferentially occurs on the oropharyngeal mucosa, the urogenital mucosa, and the soles. In contrast to its malignant clinical picture, the tumor grows locally invasive but is histologically benign and metastasizes rarely. METHODS: We report the uncommon occurrence of a large verrucous carcinoma on apparently uninvolved skin in the right axilla in a 47-year-old male. RESULTS: Histologic examination reveals a cauliflower-like tumor consisting of deep invaginated epidermal proliferation with rabbit burrow-like, keratin-filled sinus formations; the basement membrane, however, remains intact. Immunohistology showed positivity for pancytokeratin (KL-1) and cytokeratin (CK) 18 and negativity for CK7, and assessment of the proliferative activity of the tumor cells revealed low percentage of Ki-67 expression. Furthermore, there were only scattered cells expressing p53 or bcl-2. Polymerase chain reaction excluded the presence of human papillomavirus. After complete excision, no signs of recurrence occurred over a follow-up period of three years. CONCLUSION: Verrucous carcinoma should be distinguished from typical squamous cell carcinoma. The clinicopathological features, differential diagnosis, and therapy are discussed here together with the molecular biologic aspects of the tumor.

Shifts in cellular localization of moesin in normal oral epithelium, oral epithelial dysplasia, verrucous carcinoma and oral squamous cell carcinoma.

BACKGROUND: Moesin, a member of ERM (ezrin/radixin/moesin) family, links actin filaments of cell surface structure to the cell membrane. The purpose of the study is to assess the shifts in cellular distribution of moesin in normal oral epithelium, oral epithelial dysplasia (OED), verrucous carcinoma (VC), and oral squamous cell carcinoma (OSCC). METHODS: The expression of moesin was evaluated immunohistochemically in paraffin-embedded tissues of 59 specimens of OSCC, 35 specimens of OED, 17 specimens of VC, and five specimens of normal oral epithelium. RESULTS: In the normal oral epithelia, all specimens showed a pattern of membranous expression against the anti-moesin antibody in the basal layer cells. In the OED specimens, moesin was dominantly expressed in the cell membrane except for the cornified layer. In VC and OSCC specimens, almost the whole of the carcinoma cells were stained with anti-moesin antibody. However, in OSCC samples, moesin was markedly expressed increasingly in the cytoplasm and decreasingly in the cell membrane, as compared with OED and VC. In addition, there was a significant correlation between the pattern of moesin expression and tumor differentiation in OSCC. CONCLUSIONS: Our results suggest that it is useful to detect the moesin expression as adjunct to screening mucosal lesions in the oral cavity.

Immunohistochemical expression of Mdm2 and p53 in penile verrucous carcinoma.

Verrucous carcinoma (VC) of the penis is an uncommon squamous tumor that pursues a biologically indolent course. Unlike conventional squamous cell carcinoma (SCC) of the penis, pathogenic roles for human papillomavirus (HPV) infection and p53 mutation have not been reported in VC. We compared the immunohistochemical expression of Mdm2 and p53 in 7 cases of VC and 7 cases of SCC. The Mdm2 gene product preferentially labeled the perinuclear membrane in the granular layer of VC tumor cells, whereas SCC cases showed weak, focal, cytoplasmic staining for Mdm2. The mean labeling index for Mdm2 was higher in VC compared to SCC [79.3 (SE +/- 7.2) in VC vs 18.3 (SE +/- 2.4) in SCC, p < 0.001]. In SCC cases, the normal surrounding skin showed mild granular-layer staining and dysplastic foci that failed to stain with Mdm2 antibody. Weak p53 immunolabeling was seen within nuclei of scattered tumor cells in the cases of VC, whereas the SCC cases showed strong nuclear staining of p53 throughout the tumors. The mean labeling index for p53 was lower in VC compared to SCC [24.8 (SE +/- 3.9) in VC vs 64.7 (SE +/- 9.0) in SCC, p < 0.01]. In SCC cases, the normal surrounding skin showed moderate staining for p53, preferentially confined to the basal layer. Dysplastic foci in the cases of SCC showed increased p53 labeling. In summary, immunohistochemical analysis showed significantly different levels of expression of Mdm2 and p53 in penile VC vs SCC. Overexpression of the Mdm2 gene product may be important in the pathogenesis of VC. Since Mdm2 is a negative regulator of p53, overexpression of Mdm2 may explain why p53 is down-regulated and, therefore, permissive to oncogenic transformation.

Mixed tubulopapillary hidradenoma and syringocystadenoma papilliferum occurring as a verrucous tumor.

Tubulopapillary hidradenoma (TPH)1 is a term proposed to describe morphological dermal ductal tumors with both eccrine and apocrine differentiation. The term TPH encompasses a spectrum of lesions that includes tubular apocrine adenoma (TAA) and papillary eccrine adenoma (PEA):2 PEA and TAA can be indistinguishable both clinically and histologically. We described a case of TPH with both prominent eccrine and apocrine differentiation combined with syringocystadenoma papilliferum (SCAP) over the distal extremity. This rarely encountered dermatopathological phenomenon is the sixth reported case from the literature in which PEA or TAA and SCAP were present in the same lesion.3-7 Furthermore, the tumor had a warty surface, which is histologically consistent with a typical viral verruca. Although PCR and DNA probe hybridization for human papilloma virus (HPV) types 2, 6/11, 16 and 18 failed to reveal positive results, the location and clinicopathologic correlation convinced us that superimposed HPV could not be excluded.

Papillary squamous cell carcinoma of the oral mucosa: immunohistochemical comparison with other carcinomas of oral mucosal origin.

Papillary squamous cell carcinoma (PSCC) is a poorly described variant of squamous cell carcinoma, and may be confused with verrucous carcinoma of the head and neck. To add to existing knowledge of this rare tumor, we describe two cases of PSCC arising in the oral mucosa. The lesions were composed of exophytic proliferation of atypical to overtly malignant cells similar to those of conventional squamous cell carcinoma, and invasion into the superficial region of the underlying fibrous tissue was seen in the form of islands and cords of malignant cells. Immunohistochemical assessment of cellular proliferative activity showed a significantly high mean percentage of Ki-67 expression in comparison with verrucous carcinoma, but there was no significant difference of Ki-67 expression among PSCC, conventional squamous cell carcinoma and microinvasive squamous cell carcinoma. These results suggest that the biological behavior of PSCC is analogous to that of SCC.

[Immunohistochemical and ultrastructural study of basement membrane in oral verrucous carcinoma].

OBJECTIVE: To study the immunohistochemical alteration of basement membrane (BM) type IV collagen and laminin in oral verrucous carcinoma and its BM ultrastructural variations. METHODS: 16 cases of oral verrucous carcinoma (OVC), 10 cases of oral squamous cell carcinoma (OSCC) and 9 cases of oral mild to severe epithelial dysplasia (OMSD) were studied by using a immunohistochemical S-P method, and the results were analyzed by quantitative method. 3 cases of OVC were observed by TEM. RESULTS: The BM in OVC was thicker than in OSCC and OMSD. TEM found the basal lamina in some areas showed a marked reduplication. The BM in OVC was generally intact (13/16), whereas in OSCC it was mostly discontinuous (9/10), especially around the neoplasm front or the small cord consisted of a few cells, and mostly continuous in OMSD (6/9). There was a stromal inflammatory infiltration around tumor nests for all the oral lesions, but it was much heavier in OVC than that in OSCC and OMSD (P < 0.05). There was a positive correlation between intraepithelial lymphocytic infiltration and the BM continuity for OVC(P < 0.01). CONCLUSIONS: The more continuous BM and the heavier inflammatory infiltration in the connective tissue of OVC may be related to its biological behavior.

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.

Alterations in cell proliferative activity are a common phenomenon in oral carcinogenesis. In this study, the expression of the cell cycle-associated proteins p16, pRb, p53, p27 and Ki-67 were examined by immunohistochemistry in precancerous and cancerous oral lesions, including verrucous carcinomas (VCs). Generally, expression of pRb, p53 and Ki-67 increased according to the cell proliferative activity or tumor progression, but p27 expression showed an inverse relationship. Comparing squamous cell carcinomas (SCCs) with VCs, there was a great difference in expression levels of p27, Ki-67 and p53, which seemed to reflect the different cell proliferative activities of these two tumors. Expression of p16 was low in both dysplasia and SCCs, whereas p16 expression was high in VCs. The high immunohistochemical expression for both p16 and pRb in VC is quite different compared with SCC, which may indicate a possible relationship between VC and human papillomavirus (HPV) infection.

Human papillomavirus and p53 oncoprotein in verrucous carcinoma of the larynx.

The incidence of p53 antigen and human papillomavirus (HPV) expression in archival formalin-fixed, paraffin-embedded tissue sections from verrucous carcinoma of the larynx was determined using immunohistochemistry. The p53 oncoprotein was detected in four of 10 tissue samples (40 per cent). The same number of tumours had HPV antigen, and three cases had both p53 oncoprotein and HPV antigen. All positive cases were from heavy smokers and drinkers. After surgical treatment, no tumour recurrence was present in our series. Four patients developed a second head and neck neoplasm and death occurred in three. Three of the patients with second tumour had p53 positive immunoreactivity and two had p53 and HPV expression. Verrucous carcinoma of the larynx presented with overexpression of p53 antigen in a similar percentage to other head and neck cancers. The p53 immunohistochemical determination is well correlated with HPV detection and could have prognostic value in these tumours, but no statistical evidence was present.

Proliferating cell nuclear antigen distribution in verrucous carcinoma of the skin.

Verrucous carcinoma (VC) of the skin is a rare variety of well-differentiated squamous cell carcinoma (SCC) characterized by aggressive local growth and a low metastatic potential. These tumours are known to have histological and virological features similar to classic warts or condylomata. The aim of the present study was to map the proliferative compartment in VC (n = 7) in comparison with warts (n = 10) and typical well-differentiated SCC (n = 10). The proliferating cells were detected by immunostaining of proliferating cell nuclear antigen (PCNA) in formalin-fixed, paraffin-embedded tissue sections, using the commercially available anti-PCNA monoclonal antibody PC10. Normal epidermis served as a positive control and reference. In VC and warts, the PCNA-positive cells were principally located at the periphery of lesions, in the basal layer of the tumour islands. In some warts, however, stronger PCNA expressed was noted in the superficial layers, of the lesions corresponding to virus-infected keratinocytes (koilocytotic cells). In contrast, in SCC, PCNA-positive cells were randomly scattered throughout the tumours. Our findings suggest that, on the basis of mapping of PCNA distribution, VC resembles large warts or condylomata rather than typical SCC. Thus, VC appears to be a distinct clinical entity, intermediate between these two types of lesions, not only because of its clinical entity, intermediate between these two types of lesions, not only because of its clinical and virological features, but also with regard to its proliferative organization.

The detection of human papillomavirus deoxyribonucleic acid in intraepithelial, in situ, verrucous and invasive carcinoma of the penis.

PURPOSE: We study the prevalence of human papillomavirus deoxyribonucleic acid (DNA) in squamous cell carcinoma and control tissue of the penis. MATERIALS AND METHODS: The technique of polymerase chain reaction DNA amplification was used to detect specific human papillomavirus DNA sequences in archival pathological and control tissues. We analyzed 42 cases of invasive squamous cell carcinoma, 13 of carcinoma in situ, 12 of penile intraepithelial neoplasia, 3 of verrucous carcinoma and 25 of balanitis xerotica obliterans, as well as 29 routine neonatal circumcision specimens and 32 adult circumcision specimens. RESULTS: Overall, the detection rates for human papillomavirus DNA in the study and control tissues were 55% (23 of 42 cases) for invasive squamous cell carcinoma, 92% (12 of 13) for carcinoma in situ, 92% (11 of 12) for penile intraepithelial neoplasia, 0% (0 of 3) for verrucous carcinoma, 4% (1 of 25) for balanitis xerotica obliterans, 0% (0 of 29) for neonatal circumcision and 9% (3 of 32) for adult circumcision. In all groups human papillomavirus type 16 was the most common genotype identified. CONCLUSIONS: The prevalence of human papillomavirus DNA is significantly greater in carcinoma of the penis than in control tissue. Moreover, the prevalence is greater in noninvasive lesions (carcinoma in situ and penile intraepithelial neoplasia) than in invasive carcinoma.

Is the carbohydrate sialosyl-Tn a marker for altered, non-malignant activity in squamous epithelium in the head and neck region?

Cell surface carbohydrates are involved in many cell functions such as cellular differentiation, adhesion, and invasion. A carbohydrate, sialosyl-Tn (STn), is expressed in many human carcinomas but generally not in normal epithelia. In the oral mucosa, however, STn has recently been observed on basal cells in some lesions with epithelial hyperplasia and dysplasia. The aim of this study was to carry out a systematic investigation of STn expression on epithelial basal cells in hyperplastic, 'borderline' malignant, and malignant head and neck lesions, to see if the expression of STn is associated specifically with hyperplastic conditions. Using the primary monoclonal antibody TKH2, normal controls did not reveal STn. STn was detected on probably post-mitotic basal cells in hyperplastic head and neck lesions and on basal cells adjacent to cancers, but not within the carcinomas. A Ki67 antibody reacted with basal cells in other locations. The most highly differentiated lesions, such as focal epithelial hyperplasia and verrucous hyperplasia, revealed a high percentage (86 per cent in both cases) of STn reactivity. The least-differentiated verrucous carcinomas (VCs) and keratoacanthomas (KAs) did not express STn, in contrast to the highly differentiated VCs and KAs. These findings indicate that STn-negative cases may have a greater malignant potential that the STn-positive cases. In conclusion, STn expressed on basal cells is possibly a marker for non-malignant conditions with altered basal cell activity and for highly differentiated verrucous carcinomas.

p53 protein expression in sequential biopsies of oral dysplasias and in situ carcinomas.

Immunohistochemically detectable levels of p53 may be seen early in the malignant transformation of some neoplasms. To determine if p53 is immunocytochemically detectable, and therefore presumptively abnormal, in oral dysplasias and in situ carcinomas, and to explore the natural history of p53 protein expression in these lesions, sequential biopsies from patients with lesions occurring in the same anatomic site were examined. Formalin-fixed, paraffin-embedded sections from 19 patients were evaluated immunohistochemically for p53 protein using antibody clones Pab1801 and BP53-12. With two exceptions, comparable results were observed with these antibodies. p53 protein was detected immunocytochemically in 6 of 13 patients with dysplasias; 3 of these progressed to p53-positive invasive carcinoma, one advanced to a more severe grade of p53-positive dysplasia, one developed into a p53-negative verrucous carcinoma, and one represented a p53-positive dysplasia developing five years after treatment of a p53-positive carcinoma. The p53-positive dysplasias, which were found in all subtypes (mild, moderate, severe), preceded histologic malignant change by months to years. p53 detection was evident in 4 of 6 patients with in situ lesions. Sequential biopsies of three of these lesions showed no change in lesion histology or p53 staining, and one lesion advanced to a p53-positive carcinoma. It is concluded that p53 protein may be detected early in the development of a subset of p53-positive oral squamous cell carcinomas. This phenomenon may be seen in dysplasias and in situ lesions, and it may have prognostic implications.

HPV detection and p53 alteration in squamous cell verrucous malignancies of the lower genital tract.

We examined five cases of verrucous carcinoma (VC) and two cases of giant condyloma of Buschke-Löwenstein (GCBL) associated with invasive squamous cell carcinoma (ISCC), by immunocytochemistry and molecular techniques. Neither human papillomavirus (HPV) footprints nor p53-altered expression and/or mutation were observed among the cases of VC. By contrast, both cases of GCBL with ISCC turned out to be HPV 6 or 11 positive, showed overexpression of p53 and, one of the two, a mutation in the nucleotide sequence of this tumor suppressor gene. The results point out that VC and GCBL with ISCC, in spite of some morphologic similarities, are two distinct entities, the former being unrelated to both HPV and p53 inactivation and the latter related to both. Regarding p53, immunocytochemical and molecular data on GCBL with ISCC suggest a role of mutant p53 in the progression of malignancy into invasion.