PD-L1 immunoexpression and molecular characterization of histological subtypes in urothelial carcinoma.

INTRODUCTION: Urothelial carcinoma (UC) has histological subtypes whose phenotype reflects their molecular diversity, behavior and response to conventional therapy. Immune checkpoint inhibitors (ICIs) have improved the management of UC by evaluation of PD-L1. In the case of PD-L1 22C3, the initiation of ICI is considered from a combined positive score (CPS) greater than 10. However, UC subtypes with absent PD-L1 22C3 expression in cases with CPS>10 may not respond to these treatments. This study aims to establish a correlation between the PD-L1 immunoexpression and molecular alterations in divergent differentiation and histological subtypes of UC (UC-s). MATERIAL AND METHODS: Twenty-six samples of UC were detected from a total of 24 patients. Two pathologists performed separately an assessment of UC-s on hematoxylin-eosin as well as PD-L1 expression. Molecular study of each case was performed by next generation sequencing (NGS). A descriptive analysis of the variables included was conducted. RESULTS: Nine cases (34.61%) showed a CPS>10, some with negative PD-L1 immunoexpression in aggressive UC-s. The molecular study revealed alterations in genes belonging to the p53/cell cycle control, RAS, and DNA repair pathways, among others. None of the alterations were exclusive to any histological subtype. DISCUSSION: Special attention should be paid to CPS>10 cases that include histological subtypes of UC with divergent expression for PD-L1 as they may not respond to treatment with ICI. We recommend examining the proportion and PD-L1 status of each subtype, especially if it has aggressive behavior.

PD-L1 immunoexpression and molecular characterization of histological subtypes in urothelial carcinoma / Inmunoexpresión de PD-L1 y caracterización molecular de subtipos histológicos de carcinoma urotelial

Introduction: Urothelial carcinoma (UC) has histological subtypes whose phenotype reflects their molecular diversity, behavior and response to conventional therapy. Immune checkpoint inhibitors (ICIs) have improved the management of UC by evaluation of PD-L1. In the case of PD-L1 22C3, the initiation of ICI is considered from a combined positive score (CPS) greater than 10. However, UC subtypes with absent PD-L1 22C3 expression in cases with CPS>10 may not respond to these treatments. This study aims to establish a correlation between the PD-L1 immunoexpression and molecular alterations in divergent differentiation and histological subtypes of UC (UC-s). Material and methods: Twenty-six samples of UC were detected from a total of 24 patients. Two pathologists performed separately an assessment of UC-s on hematoxylin–eosin as well as PD-L1 expression. Molecular study of each case was performed by next generation sequencing (NGS). A descriptive analysis of the variables included was conducted. Results: Nine cases (34.61%) showed a CPS>10, some with negative PD-L1 immunoexpression in aggressive UC-s. The molecular study revealed alterations in genes belonging to the p53/cell cycle control, RAS, and DNA repair pathways, among others. None of the alterations were exclusive to any histological subtype. Discussion: Special attention should be paid to CPS>10 cases that include histological subtypes of UC with divergent expression for PD-L1 as they may not respond to treatment with ICI. We recommend examining the proportion and PD-L1 status of each subtype, especially if it has aggressive behavior.(AU)

Introducción: El carcinoma urotelial (CU) presenta subtipos histológicos cuyo fenotipo refleja su diversidad molecular, su comportamiento y su respuesta al tratamiento. Los inhibidores de puntos de control inmunitario (ICI) han mejorado el manejo del CU mediante la evaluación de PD-L1. En el caso de PD-L1 22C3, se considera el inicio de ICI a partir de una puntuación positiva combinada (combined positive score [CPS]) mayor de 10. Sin embargo, los subtipos de CU con ausencia de expresión de PD-L1 22C3 en casos con CPS>10 podrían no responder a estos tratamientos. Este estudio pretende establecer una correlación entre la inmunoexpresión de PD-L1 y las alteraciones moleculares en áreas con diferenciación divergente y subtipos histológicos de CU (CU-s). Material y métodos: Se obtuvieron 26 muestras con CU de 24 pacientes. Dos patólogos evaluaron de manera independiente las CU-s en hematoxilina-eosina y la expresión de PD-L1. Se realizó el estudio molecular mediante Next Generation Sequencing (NGS). Se realizó un análisis descriptivo de las variables incluidas. Resultados: Nueve casos (34,61%) mostraron un CPS>10, algunos con PD-L1 negativo en los CU-s de comportamiento agresivo. El estudio molecular reveló alteraciones en genes de las vías de p53/control del ciclo celular, RAS y reparación del ADN, entre otras. Ninguna alteración fue exclusiva de algún CU-s. Discusión: Debe prestarse especial atención a los casos con CPS>10 que incluyan subtipos histológicos con expresión divergente para PD-L1, ya que podrían no responder al tratamiento con ICI. Se recomienda cuantificar la proporción y el estado de PD-L1 de cada subtipo, especialmente si es de comportamiento agresivo.(AU)

Inmunoexpresión de p53 y su relación con el grado de severidad en displasia epitelial oral / Immunoexpression of p53 and its relationship with the degree of severity in oral epithelial dysplasia

Introducción: La displasia epitelial oral (DEO) es la presencia de alteraciones celulares y tisulares, lo que puede significar una etapa anterior al desarrollo del cáncer. Múltiples marcadores han sido considerados para estimar su potencial neoplásico y evolución a carcinoma, incluyendo a la molécula p53, se considera como participe de diversos fenómenos de la homeostasis celular. Objetivo: Determinar la relación entre la inmunoexpresión de p53 DO-7 y PAb 240 con el grado de severidad de la displasia epitelial oral. Material y métodos: Se analizaron nueve muestras de DEO (tres para cada grado de severidad). La inmunoexpresión de p53 tipo silvestre (DO-7) y forma mutada (PAb 240), fue determinada a través de ensayo de inmunohistoquímica por peroxidasa. Se obtuvieron la media y desviación estándar y se realizó la prueba χ2 (p < 0.05). Resultados: La edad media fue de 65.7 ± 11.4 años, la zona anatómica con mayor presencia de DEO es el borde lateral de la lengua. Ocho de nueve muestras fueron positivas para DO-7 y solo dos para PAb 240. Conclusiones: Nuestros resultados indican que, aunque la expresión de p53 DO-7 podría estar relacionada parcialmente con la patogénesis de la displasia epitelial, no todas las displasias presentaron la forma mutada de p53 (PAb 240). Lo cual coincide con el comportamiento biológico incierto de las displasias al poder permanecer sin cambios, involucionar o transformarse

Introduction: Oral epithelial dysplasia (OED) is the presence of cellular and tissue alterations, which may mean a stage prior to the development of cancer. Multiple markers have been considered to estimate its pathogenic potential and evolution to neoplasms, including the p53 molecule, considered as participating in various phenomena of cellular homeostasis. Objective: To determine the relationship between the immunoexpression of p53 DO-7 and PAb 240 with the degree of severity of oral epithelial dysplasia. Material and methods: Nine OED samples were analyzed (three for each degree of severity). The immunoexpression of wild-type p53 (DO-7) and mutated form (PAb 240) was determined through a peroxidase immunohistochemical assay. The mean and standard deviation were obtained, and χ2 test (p < 0.05) were performed. Results: The mean age was 65.7 ± 11.4 years, with a greater presence of OED in the anatomical area of the lateral side of the tongue. Eight out of nine samples were positive for DO-7 and only two for PAb 240. Conclusions: Our results indicate that, although the expression of p53 DO-7 could be partially related to the pathogenesis of epithelial dysplasia, not all dysplasias presented the mutated form of p53 (PAb 240), which coincides that not all dysplasias have a potential for malignant transformation and that could be related to other oncogenic mechanisms (AU)

Expresión Inmunohistoquímica de Ki-67 en Lesión Central de Células Gigantes / Immunohistochemical Expression of Ki-67 in Central Giant Cell Lesion

RESUMEN: La lesión central de células gigantes (LCCG) es una lesión osteolítica benigna que en algunos casos presenta un comportamiento agresivo, con recidiva y mal pronóstico. Ki-67 es una proteína nuclear cuya función general es la regulación de la proliferación celular. Este marcador es utilizado para el reconocimiento de células en proliferación y como herramienta de pronóstico en el diagnóstico de neoplasias. El objetivo de este estudio fue cuantificar la inmunoexpresión de Ki-67 en las diferentes poblaciones celulares de las LCCG y analizar su asociación con las características clínicas, demográficas y radiográficas. Se evaluó la inmunoexpresión de Ki-67 de 17 casos de LCCG en dos poblaciones celulares: células gigantes multinucleadas (CGM) y células mesenquimatosas estromales (CME). El análisis estadístico se efectuó con el programa SAS 9.0 y SPSS versión 23.0, con un nivel alfa impuesto de P<0,05. Las CME mostraron inmunoexpresión promedio de 9,4 % y las CGM de 0,65 %. No se encontró relación estadísticamente significativa entre las características clínicas, demográficas y radiográficas de las LCCG y la inmunoexpresión de Ki-67. La expresión de Ki-67 en CME sugiere que esta población se encuentra en constante actividad celular y que las LCCG son lesiones dinámicas y en constante proceso de diferenciación.

ABSTRACT: The central giant cell lesion (CGCL) is a benign osteolytic lesion which in some cases presents an aggressive behavior with recurrence and poor prognosis. Ki67 is a nuclear protein whose general function is the regulation of cell proliferation. This marker is used to identify proliferating cells and as a prognostic tool in the diagnosis of neoplasms. The aim of this study was to quantify the immune expression of Ki-67 in the different cell populations of CGCL and analyze its association with clinical, demographic and radiographic characteristics. The Ki-67 immune expression of 17 cases of LCCG was evaluated in two cell populations: multinucleated giant cells (CGM) and stromal mesenchymal cells (SMC). The statistical analysis was carried out with SAS 9.0 and SPSS version 23.0, with an alpha tax level of P <0.05. The CME showed average immune expression of 9.4 % and the CGM of 0.65 %. No statistically significant relationship was found between the clinical, demographic and radiographic characteristics of the CGCL and the immune expression of Ki-67. The expression of Ki-67 in CME suggests that this population is in constant cellular activity, and that the CGCL are dynamic lesions in a continuous differentiation process.

Non-functioning pituitary tumors: 2012 update.

Non-functioning pituitary adenomas are the most common pituitary macroadenomas in adults, accounting for approximately 14%-28% of all clinically relevant pituitary tumors. They are a heterogeneous group of tumors that cause symptoms by compression and/or hormone deficiencies. The possibility of tumor growth is increased in macroadenomas and solid tumors as compared to microadenomas and cystic tumors. Diagnosis is based on imaging procedures (magnetic resonance imaging), but there are studies reporting promising potential biomarkers. Transsphenoidal surgery remains the first therapeutic option for large tumors with compressive symptoms. There is no evidence that endoscopic procedures improve outcomes, but they decrease morbidity. There is no unanimity in finding prognostic predictors of recurrence. Radiosurgery achieves tumor control and, sometimes, adenoma size reduction. Its adverse effects increase with higher doses and tumor sizes>4cm(3). Drug treatment is of little value. In aggressive non-functioning tumors, temozolomide (TMZ) may be used with caution because no controlled studies are available. TMZ achieves tumor control in 38%-40% of aggressive non-functioning tumors. The optimal treatment regimen and duration have not been defined yet. Lack of response to TMZ after 3 cycles predicts for treatment resistance, but initial response does not ensure optimal mid or long-term results. O6-methylguanine-DNA methyltransferase expression has a limited predictive value of response to treatment with TMZ in aggressive non-functioning tumors. It should therefore not be a determinant factor in selection of patients to be treated with TMZ.