Head and neck cancer. An aetiopathogenetic study of non-endemic lymphoepithelioma.

An aetiopathogenetic analysis of non-endemic nasopharyngeal carcinoma (NPC) in European and Southern American patient groups was performed. Specifically, the study sought to determine the proportion of Epstein-Barr Virus (EBV)-positive tumour cells in NPC patients in two very different populations (Europe and South America) in areas not associated with a high incidence of NPC. Clinical data (age, sex and onset of clinical disease) were also analyzed. A total of 50 NPC samples, 24 from a European hospital (EH) and 26 from two South American hospitals (SAH), were included. Nuclear staining for Epstein-Barr virus-encoded small RNA (EBER) was performed by in situ hybridization (ISH). Latent membrane protein 1 (LMP1) expression was measured by immunohistochemical (IHC) analysis. A higher incidence of NPC was observed in patients > 40 years of age in EH; in SAH, by contrast, the incidence was higher in patients aged ≤ 40 years. Cervical lymph node metastasis was detected in 31 patients (of whom 84.6% were from SAH). A total of 72% of samples were EBERpositive; the incidence of EBER positivity was greater in type 3 NPCs. EBV was detected in a large proportion of epithelial cells in samples from both EH and SAH (75% vs. 69.2%, respectively). An association was found between EBER detection in lymphocytes and patient origin (p = 0.0001). LMP1 expression was detected in 64% of patients. ISH for the detection of EBER is the most sensitive technique for demonstrating EBV in tumour tissue. The incidence of EBV was not significantly greater in either of the study populations, but was significantly higher in patients with type 3 NPC. Definitive histological diagnosis of NPC was reached earlier in EH than in SAH, where metastases were more frequently diagnosed, suggesting that the disease had reached a more advanced stage by the time treatment was started.

The cadherin-catenin complex in laryngeal squamous cell carcinoma.

Abnormal Wnt signaling and impaired cell-cell adhesion due to abnormal E-cadherin and ß-catenin function have been implicated in many cancers, but have not been fully explored in laryngeal squamous cell carcinoma. In this study, ß-catenin cellular location and E-cadherin expression levels were analyzed in 16 laryngeal squamous cell carcinomas (LSCCs) (9 glottic and 7 supraglottic) and 11 samples of non-tumoral inflammatory larynx tissue, using immunohistochemical methods. All non-tumoral tissues showed equally strong membranous expression of ß-catenin, while cytoplasmic expression was found in only 3 of the 11 samples. By contrast, whereas 8/9 glottic LSCCs exhibited only membranous expression of ß-catenin, 6/7 supraglottic LSCCs displayed both membranous and cytoplasmic expression (p = 0.003). Strong E-cadherin staining was observed in 9/11 non-tumoral tissues and 7/9 glottic LSCCs, whereas 4/7 supraglottic LSCCs exhibited weak expression. Reduced membrane expression of E-cadherin and cytoplasmic retention of ß-catenin in supraglottic LSCC seems to be related with more aggressive biological behavior which has been described in clinical studies. Further research is required to clarify the involvement of ß-catenin in the mechanism associated with malignant transformation in laryngeal tissues.

Ki-ras mutational analysis in rat follicular-cell proliferative lesions of the thyroid gland induced by radioactive iodine and potassium perchlorate.

Although in both human and experimental pathology ras mutations have been related to the origin and progression of follicular-cell tumours, reports differ considerably with respect to the frequency of such mutations. The present paper reports, using direct sequencing, the incidence of Ki-ras mutations (codons 12 and 13) in follicular-cell carcinomas of the thyroid gland in Wistar rats induced by administration of radioactive iodine and potassium perchlorate. Direct sequencing revealed no mutations in the amplified gene segment of any of the 72 carcinoma samples studied. This absence of mutations agrees with some and is in sharp contrast with other previous reports in the literature, both for experimental animals and in studies of human thyroid follicular-cell carcinoma. Our results suggest that Ki-ras activation via mutations at codons 12 and 13 is neither a constant event nor an early event in the development of rat thyroid follicular-cell carcinoma.

The Ret proto-oncogene in the WAG/Rij rat strain: an animal model for inherited C-cell carcinoma?

WAG/Rij rat strain has been suggested as an animal model for the study of inherited human medullary thyroid carcinoma (MTC), due to its high incidence of spontaneous C-cell thyroid tumours. Although the role of the Ret proto-oncogene mutations, as responsible for human MTC, is well established, nothing has been published concerning this putative animal model. Based upon the previously reported rat Ret sequence, exons 10, 11, 13, 14, 15, and 16, known to carry activating mutations in humans, have been analysed in the WAG/Rij rat by PCR, single strand conformational polymorphism (SSCP) and direct sequencing. Neither the germline nor MTC samples showed any Ret sequence difference in the exons when analysed in comparison to a non-MTC-susceptible rat strain. Our results indicate that Ret exons relevant in humans are not involved in WAG/Rij rat MTC, as expected, and this questions the validity of this strain as a model for the human disease, and suggests there must be additional mechanisms for the genesis and progression of rat MTC.

[Advances in the diagnosis of ENT tumors in childhood]. / Avances en el diagnóstico de los tumores otorrinolaringológicos.

In the present study we review ENT tumor pathology in childhood. Only the most salient aspects are emphasized and the variety of entities reviewed was restricted. Molecular biology techniques reveal infection by human papilloma virus (types 6 and 11) in 50 % of papillomas, while immunohistochemical techniques are less effective in papilloma virus detection. The myofibroblastic nature of nasal angiofibroma has been demonstrated and its incidence is 25 times more frequent in patients with familial polyposis of the colon. Overexpression of p53 occurs in the initial stages of nasopharyngeal carcinoma, while overexpression of c-myc is correlated with an unfavorable prognosis. Recently, olfactory neuroblastoma has been shown not to express the protein product of the MIC-2 gene (antibody 12E7), thus the hypothesis that it could be a member of the Ewing tumor family (neuroectodermal peripheral tumors) has not been confirmed, although it is a primitive neural tumor. The head and neck rhabdomyosarcoma with the best prognosis is that located in the orbit, and cytogenetic studies have shown chromosomic translocation t(2;13) in 50 % of these childhood tumors when they are of the alveolar-type, while trisomy of chromosome 2 or 20 is more characteristic of the embryonic-type. Currently, any classifying features of ENT lymphomas must be based on the Revised European-American Classification of Lymphoid Neoplasms (REAL). Papillary and medullary carcinomas are the most common histological types of thyroid carcinoma in childhood. Alterations in ret/PTC play a significant role in the pathogenesis of both.

Avances en el diagnóstico de los tumores otorrinolaringológicos / Advances inthe diagnosis of enttumors in childhood

En el presente trabajo se revisa la patología tumoral otorrinolaringológica propia de la infancia. Se incide sólo en aquellos aspectos más sobresalientes, pues la variedad de entidades en estudio es restringida. En el 50 por ciento de los papilomas puede demostrarse la infección por virus del papiloma humano (tipos 6 y 11) mediante técnicas de biología molecular, siendo menor la capacidad demostrativa de la inmunohistoquímica. En el angiofibroma nasal se ha puesto en evidencia la naturaleza miofibroblástica y su incidencia es 25 veces más frecuente en poblaciones de pacientes con poliposis adenomatosa familiar del colon. En el carcinoma nasofaríngeo ocurre sobreexpresión de p53 en los estadios iniciales y la sobreexpresión de c-myc se correlaciona con peor pronóstico. Recientemente se ha demostrado que el neuroblastoma olfatorio no expresa la proteína producto del gen MIC2 (anticuerpo 12E7), por lo que no se confirma la hipótesis de que puede ser miembro de la familia del tumor de Ewing (tumores neuroectodérmicos periféricos), aunque sí es un tumor neural primitivo. El rabdomiosarcoma de cabeza y cuello con mejor pronóstico es el orbitario, y los estudios citogenéticos han señalado la translocación cromosómica t(2;13) en el 50 por ciento de estos tumores infantiles cuando son de tipo alveolar, mientras que la trisomía del cromosoma 2 o del 20 es más peculiar del tipo embrionario. Por otro lado, cualquier asunto clasificatorio de los linfomas del área otorrinolaringológica, actualmente tiene que basarse en la clasificación REAL (Revised European-American Classification of Lymphoid Neoplasms).Entre los tipos histológicos de carcinoma de tiroides, el papilar y el medular son los que más relieve poseen en la edad infantil y en la génesis de ambos, las alteraciones del protooncogén ret desempeñan un papel importante (AU)

Prognostic value of DNA flow cytometry in sympathoadrenal paragangliomas.

OBJECTIVE: To determine whether ploidy patterns are related to prognosis in sympathoadrenal paragangliomas (SAP) using flow cytometry. STUDY DESIGN: DNA flow cytometric analysis of formalin-fixed, paraffin-embedded tumor samples from 36 patients with SAP was performed. Eight cases fulfilled at least one of the following malignancy criteria: (1) extensive invasion of adjacent structures (5 cases), (2) local recurrence (3 cases), or (3) metastases (4 cases). RESULTS: Of the 36 tumors, 22 (61%) showed nondiploid patterns (12 aneuploid, 10 tetraploid). All diploid tumors were benign, while all malignant cases showed nondiploid patterns (P = .0131). The differences between diploid and aneuploid tumors and between diploid and tetraploid tumors, with regard to the malignancy of the disease, were statistically significant (P = .03311 and .01976, respectively). Only one malignant tumor had a DNA index < 1.75 (P = .00259). CONCLUSION: Anomalous DNA ploidy patterns are frequent in SAP, without necessarily implying malignancy. However, diploid DNA content may be a marker of a good prognosis. The likelihood of malignancy is greater in the tetraploid and peritetraploid range.

[DNA ploidy determination with flow cytometry, Ki-67 index and overexpression of p53 protein in 121 T1 superficial bladder carcinomas. Retrospective studies. Part II: Prognostic value and usefulness in the indication for prophylactic treatment with BCG]. / Determinación de ploidía de ADN mediante citometría de flujo, indice Ki-67 y sobre-expresión de proteína p53 en 121 carcinomas superficiales de vejiga T1. Estudio retrospectivo. 2a Parte: Valor pronóstico y utilidad en la indicación de tratamiento profiláctico con BCG.

OBJECTIVE: Evaluate the utility of Ki-67 label index, p53 expression and flow cytometry-DNA ploidy in the selection of groups to be treated with prophylactic BCG and the prognostic value compared with the classic variables (grade, lymphatic permeation, multiplicity, volume, primary). MATERIAL & METHOD: 121 superficial bladder tumors T1. 10% Cut-off level for Ki-67 and p53. Aneuplody is defined as a tumor with DNA index different of 1 or more than 20% in G2-M phase. 71 (58.7%) received BCG. RESULTS: In uni and multivariate analysis positivity to Ki-67 is correlated with recurrence. Progression is correlated with lymphatic permeation (p .0003), volume (p .016), ploidy (p .022) and positivity to p53 (p .007). In multivariate analysis, volume and positivity to p53 are independent variables. None were of utility to prevent recurrence, but Ki-67 positive or aneuploid treated tumors had less progression (p .025 and p .009 respectively). The p53 negative treated tumors had less progression too. CONCLUSIONS: Only Ki-67 is correlated with tumoral recurrence. P53 and tumor volume are correlated with stage progression. If the results are confirmed with bigger series, the Ki-67 positive and/or aneuploid tumors would obtain benefits of prophylactic treatment with BCG.

Determinación de ploidía de adn mediante citometría de flujo, índice Ki-67 y sobre-expresión de proteína p53 en 121 carcinomas superficiales de vejiga T1. estudio retrospectivo. 2ª parte: valor pronóstico y utilidad en la indicación de tratamiento profiláctico con BCG / Flow cytometry. DNA ploidy, Ki-67 label and overexpression of P53 protein in 121 T1 superficial bladder cancer. Retrospective study. 2nd Part: Prognostic value and utility in the selection of the treatment with prophylactic BCG

OBJETIVO: Valorar la utilidad del índice Ki-67, la expresión de proteína p53 y la ploidía de ADN para seleccionar grupos que se beneficien de terapia profiláctica con BCG y la capacidad pronóstica comparándola con las variables clásicas (grado, permeación linfática, volumen tumoral, multiplicidad, primario). MATERIAL Y MÉTODO: 121 carcinomas vesicales T1. Nivel de corte para Ki-67 y p53 del 10 por ciento. Se considera aneuploide cuando el tumor tiene un índice de ADN distinto de 1 ó más del 20 por ciento de la población en fase G2-M. 71 (58,7 por ciento) recibieron BCG. RESULTADOS: Ninguna de las variables clásicas tiene valor pronóstico para recidiva, y de las tres técnicas utilizadas sólo el ser Ki-67 positivo (p 0.001), confirmándose en el estudio multivariante. Para progresión tumoral alcanzan significación, la permeación linfática (p 0.0003), el volumen tumoral (p .016), la ploidía (p 0.022) y la positividad para p53 (p 0.007), confirmándose en el estudio multivariante el volumen tumoral y la positividad para p53. Ninguna de las variables fue útil para seleccionar grupos que disminuyeran su recidiva tumoral. Sin embargo los tumores aneuploides y/o Ki-67 positivos que recibieron tra-tamiento profiláctico progresaron menos (p 0.009 y p 0.025 respectivamente). Los p53 negativos tratados también progresaron menos (p 0.040).Combinando las variables, sólo los Ki-67 positivo y aneuploides se benefician de tratamiento (p 0.031). CONCLUSIONES: Ki-67 es la única variable que se correlaciona con recidiva tumoral. La progresión a estadio infiltrante se correlaciona con la positividad para p53 y el volumen tumoral. Si los resultados se confirman en series más amplias, los tumores Ki-67 positivos y/o aneuploides se beneficiarían de tratamiento profiláctico con BCG (AU)

Determinación de ploidía de ADN mediante citometría de flujo, índice Ki-67 y sobreexpresión de proteína p53 en 121 carcinomas superficiales de vejiga T1. Estudio retrospectivo correlación con las variables clásicas / Flow cytometry-DNA ploidy, Ki67 label and overexpression of P53 protein in 121 T1 superficial bladder cancer. Retrospective study. 1st Part: Corelation with classic variables

OBJETIVO: Observar la correlación entre el índice Ki-67, la expresión de proteína p53 y la ploidía de ADN mediante citometría de flujo con las variables clásicas (grado, permeación linfática, volumen tumoral, multiplicidad, primario).MATERIAL Y MÉTODO: 121 carcinomas vesicales T1. Nivel de corte para Ki-67 y p53 del 10 por ciento. Se considera aneuploide cuando el tumor tiene un índice de ADN distinto de 1 ó más del 20 por ciento de la población en fase G2-M.RESULTADOS: Se aprecia una correlación estadísticamente significativa entre las tres técnicas y las variables grado y permeación linfática, así como de las tres técnicas entre sí. El índice Ki-67 y la expresión de proteína p53 distingue entre G1, G2 frente a G3 y Lx, L0 frente a L1. Se aprecia también relación entre volumen tumoral y positividad para p53.CONCLUSIONES: La aneuploidía y la positividad para Ki-67 y p53 aumenta conforme aumenta el grado y la permeación linfática. (AU)

[DNA ploidy determination with flow cytometry, Ki-67 index, and overexpression of p53 protein in 121 T1 superficial bladder carcinoma. Retrospective study. Correlation with classic variables]. / Determinación de ploidía de ADN mediante citometría de flujo, índice Ki-67 y sobreexpresión de proteína P53 en 121 carcinomas superficiales de vejiga T1. Estudio retrospectivo. Correlación con las variables clásicas.

OBJECTIVE: Observe the correlation between Ki-67 label index, p53 expression and flow cytometry-DNA ploidy with the classic variables (grade, lymphatic permeation, multiplicity, volume, primary). MATERIAL AND METHOD: 121 superficial bladder tumors T1. 10% Cut-off level for Ki-67 and p53. Aneuploidy is defined as a tumor with DNA index different of 1 or more than 20% in G2-M phase. RESULTS: Statistical correlation with grade and lymphatic permeation. Ki-67 label index and p53 expression can distinguish between G1, G2 vs G3 and Lx, L0 vs. L1. The volume correlates with positivity to p53. CONCLUSIONS: Aneuploidy and positivity to Ki-67 and p53 increase with grade and lymphatic permeation.

cDNA sequence and genomic structure of the rat RET proto-oncogene.

The RET proto-oncogene, a member of the Receptor Tyrosine Kinase family, plays a crucial role during the development of the excretory system and the enteric nervous system, as demonstrated by in vivo animal studies and by its involvement in the pathogenesis of several human neurocristopathies like Hirschsprung disease and Multiple Endocrine Neoplasia type 2. Using a multistep RT-PCR approach we have isolated and sequenced the cDNA of the whole rat RET proto-oncogene, reporting the deduced amino acid sequence in comparison with the human and mouse counterparts. Moreover, two different isoforms (RET9 and RET51) have been confirmed in the rat, while a third RET isoform demonstrated in human (RET43) has not resulted to be conserved in this species. Finally, we have determined the genomic structure of the rat RET proto-oncogene comparing the exon-intron boundaries and intron sizes with the known structure of the human homologous gene. Our findings will facilitate the molecular study of appropriate rat models of RET related human diseases.

Correlation between gender and spontaneous C-cell tumors in the thyroid gland of the Wistar rat.

In many rat strains, C-cell hyperplasia occurs in an age-dependent manner and is often associated with multifocal C-cell carcinoma. The purpose of this study was to investigate the spectrum of spontaneous, proliferative C-cell disorders by gender in Wistar rats throughout their lifespan. The incidence of C-cell hyperplasia shows a significant increase with age (P<0.001) and is much higher in female rats than in male rats (P<0.05). From 3 to 24 months of life, 27.5% of female rats showed a normal C-cell pattern, 55.0% showed C-cell hyperplasia, and 17.5% showed C-cell tumors; while 57.5% of male rats showed a normal C-cell pattern, 32.5% showed C-cell hyperplasia, and 10% showed C-cell tumors. Although the overall frequency of C-cell neoplasms in females was nearly double that in males, these data are not statistically significant. However, the number of C-cell tumors showed a significant increase with age (P<0.05). Therefore, we can conclude that there were significant differences in the incidence of the total spectrum of C-cell proliferative abnormalities in the thyroid gland of Wistar rats that were both age-dependent and gender-dependent.

Expression of c-erbB-2 oncoprotein in human thyroid tumours.

AIMS: c-erbB-2 expression has been found to be a potential marker of aggressive biological behaviour in some tumours, but the role played by this oncoprotein in the development and maintenance of thyroid tumours is still controversial. Therefore our objective was to determine whether c-erbB-2 was overexpressed in a large retrospective series of human thyroid tumours, including both from follicular and C-cell differentiation. METHODS AND RESULTS: We have studied 67 thyroid tumours (10 follicular adenomas, 11 follicular carcinomas, three anaplastic carcinomas, 25 papillary carcinomas and 18 medullary carcinomas and 16 metastases) by immunohistochemistry using an antigen retrieval method for paraffin-embedded material and a specific polyclonal antibody against the intracytoplasmic part of c-erbB-2 oncoprotein. There are marked differences in the pattern of c-erbB-2 immunoreactivity depending on the type of thyroid tumour. Thus, no expression of the oncoprotein has been found in follicular adenomas, follicular carcinomas and anaplastic carcinomas, but 52% of papillary carcinomas (membranous and diffuse cytoplasmic patterns) and all medullary carcinomas (granular cytoplasmic pattern) are immunopositive. CONCLUSIONS: Our results indicate that overexpression of c-erbB-2 oncoprotein is easily identifiable by immunohistochemistry in paraffin sections of certain thyroid tumours after applying an antigen retrieval method. This study suggests that c-erbB-2 oncoprotein may play some role in disease progression in papillary and medullary thyroid carcinomas, but the significance of the different immunohistochemical patterns merits further investigations.