Tirbanibulin: review of its novel mechanism of action and how it fits into the treatment of actinic keratosis. / Tirbanibulina: revisión de su mecanismo de acción novedoso y de cómo encaja en el tratamiento de la queratosis actínica.

Actinic keratosis (AK) is a skin condition characterized by the proliferation of mutated keratinocytes that can develop into squamous cell carcinoma. Available therapies, although effective, are associated with a high frequency of severe local skin reactions. Tirbanibulin, one of the treatments for AK currently in development, is a new synthetic chemical entity with anti-proliferative and anti-tumor effects, both in vitro and in vivo, with proved efficacy in the treatment of AK, which has been recently demonstrated in two phase III clinical trials. In the present review, the tirbanibulin mechanism of action, based on the relevant literature and the results of several unpublished preclinical studies, is shown. In addition, the current scenario regarding the available treatments and how the novel tirbanibulin mechanism of action fits into the treatment of AK is raised.

Tirbanibulina: revisión de su mecanismo de acción novedoso y de cómo encaja en el tratamiento de la queratosis actínica / Tirbanibulin: review of its novel mechanism of action and how it fits into the treatment of actinic keratosis

La queratosis actínica (QA) es una afección cutánea caracterizada por la proliferación de queratinocitos mutados que pueden convertirse en carcinoma escamoso cutáneo. Las terapias disponibles, aunque efectivas, están asociadas con una alta frecuencia de reacciones cutáneas locales graves. Tirbanibulina, uno de los tratamientos para la QA actualmente en desarrollo, es un nuevo fármaco sintético de origen químico con potentes efectos antiproliferativos y antitumorales in vitro e in vivo con eficacia probada en el tratamiento de la QA, demostrada recientemente en dos ensayos clínicos de faseIII. En la presente revisión se muestra el mecanismo de acción de tirbanibulina en base a la literatura relevante y los resultados de varios estudios preclínicos no publicados. Además, se plantea el escenario actual en cuanto a los tratamientos disponibles y cómo el mecanismo de acción novedoso de tirbanibulina encaja en el tratamiento de la QA (AU)

Actinic keratosis (AK) is a skin condition characterized by the proliferation of mutated keratinocytes that can develop into squamous cell carcinoma. Available therapies, although effective, are associated with a high frequency of severe local skin reactions. Tirbanibulin, one of the treatments for AK currently in development, is a new synthetic chemical entity with anti-proliferative and anti-tumor effects, both in vitro and in vivo, with proved efficacy in the treatment of AK, which has been recently demonstrated in two phase III clinical trials. In the present review, the tirbanibulin mechanism of action, based on the relevant literature and the results of several unpublished preclinical studies, is shown. In addition, the current scenario regarding the available treatments and how the novel tirbanibulin mechanism of action fits into the treatment of AK is raised (AU)

[Translated article] Tirbanibulin: review of its novel mechanism of action and how it fits into the treatment of actinic keratosis / Tirbanibulina: revisión de su mecanismo de acción novedoso y de cómo encaja en el tratamiento de la queratosis actínica

Actinic keratosis (AK) is a skin condition characterized by the proliferation of mutated keratinocytes that can develop into squamous cell carcinoma. Available therapies, although effective, are associated with a high frequency of severe local skin reactions. Tirbanibulin, one of the treatments for AK currently in development, is a new synthetic chemical entity with anti-proliferative and anti-tumor effects, both in vitro and in vivo, with proved efficacy in the treatment of AK, which has been recently demonstrated in two phase III clinical trials. In the present review, the tirbanibulin mechanism of action, based on the relevant literature and the results of several unpublished preclinical studies, is shown. In addition, the current scenario regarding the available treatments and how the novel tirbanibulin mechanism of action fits into the treatment of AK is raised (AU)

La queratosis actínica (QA) es una afección cutánea caracterizada por la proliferación de queratinocitos mutados que pueden convertirse en carcinoma escamoso cutáneo. Las terapias disponibles, aunque efectivas, están asociadas con una alta frecuencia de reacciones cutáneas locales graves. Tirbanibulina, uno de los tratamientos para la QA actualmente en desarrollo, es un nuevo fármaco sintético de origen químico con potentes efectos antiproliferativos y antitumorales in vitro e in vivo con eficacia probada en el tratamiento de la QA, demostrada recientemente en dos ensayos clínicos de faseIII. En la presente revisión se muestra el mecanismo de acción de tirbanibulina en base a la literatura relevante y los resultados de varios estudios preclínicos no publicados. Además, se plantea el escenario actual en cuanto a los tratamientos disponibles y cómo el mecanismo de acción novedoso de tirbanibulina encaja en el tratamiento de la QA (AU)

Position paper on a simplified histopathological classification of basal cell carcinoma: results of the European Consensus Project.

BACKGROUND: Histopathological classification of basal cell carcinoma (BCC) has important prognostic and therapeutic implications, but reproducibility of BCC subtyping among dermatopathologists is poor. OBJECTIVES: To obtain a consensus paper on BCC classification and subtype definitions. METHODS: A panel of 12 recognized dermatopathologists (G12) from nine European countries used a modified Delphi method and evaluated 100 BCC cases uploaded to a website. The strategy involved five steps: (I) agreement on definitions for WHO 2018 BCC subtypes; (II) classification of 100 BCCs using the agreed definitions; (III) discussion on the weak points of the WHO classification and proposal of a new classification with clinical insights; (IV) re-evaluation of the 100 BCCs using the new classification; and (V) external independent evaluation by 10 experienced dermatopathologists (G10). RESULTS: A simplified classification unifying infiltrating, sclerosing, and micronodular BCCs into a single "infiltrative BCC" subtype improved reproducibility and was practical from a clinical standpoint. Fleiss' κ values increased for all subtypes, and the level of agreement improved from fair to moderate for the nodular and the unified infiltrative BCC groups, respectively. The agreement for basosquamous cell carcinoma remained fair, but κ values increased from 0.276 to 0.342. The results were similar for the G10 group. Delphi consensus was not achieved for the concept of trichoblastic carcinoma. In histopathological reports of BCC displaying multiple subtypes, only the most aggressive subtype should be mentioned, except superficial BCC involving margins. CONCLUSIONS: The three BCC subtypes with infiltrative growth pattern, characteristically associated with higher risk of deep involvement (infiltrating, sclerosing, and micronodular), should be unified in a single group. The concise and encompassing term "infiltrative BCCs" can be used for these tumors. A binary classification of BCC into low-risk and high-risk subtypes on histopathological grounds alone is questionable; correlation with clinical factors is necessary to determine BCC risk and therapeutic approach.

MicroRNA31 and MMP-1 contribute to the differentiated pathway of invasion -with enhanced epithelial-to-mesenchymal transition- in squamous cell carcinoma of the skin.

Epithelial to mesenchymal transition (EMT) is an important mechanism of invasion in cutaneous squamous cell carcinomas (cSCCs) and has been found to be enhanced in tumors originated from actinic keratosis with transformation limited to the basal epithelial layer -differentiated pathway-, compared to cases with invasion subsequent to complete epidermal transformation -classical pathway-. Several microRNAs and proteins can contribute to EMT modulation in cSCCs. MicroRNA21 and microRNA31 are involved in posttranscriptional regulation of protein expression and could play a relevant role in EMT and cSCC progression. Throughout the EMT process upregulation of matrix metalloproteinases (MMPs) enhances invasiveness and MMP-1 and MMP-3 contribute to local invasion, angiogenesis and metastasis in cSCCs. Additionally, cSCC development is associated with PTEN loss and NF-κB, NOTCH-1 and p63 activation. The aim of this work is to identify differences in the expression of those molecules between both pathways of cSCCs development. Eight tissue microarrays from 80 consecutive cSCCs were analyzed using LNA-based miRNA in situ hybridization for miRNA21 and miRNA31 evaluation, and immunohistochemistry for MMP-1, MMP-3, PTEN, NOTCH-1, NF-κB, p63 and CD31. Significantly higher expression of miRNA31 (p < 0.0001) and MMP-1 (p = 0.0072) and angiogenesis (p = 0.0199) were found in the differentiated pathway, whereas PTEN loss (p = 0.0430) was more marked in the classical pathway. No significant differences were found for the other markers. Our findings support a contribution of miRNA31 and MMP-1 in the differentiated pathway, associated to EMT and increased microvascularization. The greater PTEN loss in the classical pathway indicate that its relevance in cSCC is not EMT-related.

Granulomas en dermatopatología: principales entidades. Parte I / Granulomas in Dermatopathology: Principal Diagnoses - Part 1

En esta serie de 2 artículos realizamos una revisión de las principales entidades dermatopatológicas que cursan con granulomas. Esta primera parte se ha centrado en la aclaración de los conceptos, la presentación de los tipos de granulomas y de las células gigantes, así como en entidades muy diversas de origen no infeccioso. Algunas de ellas de origen metabólico, como la necrobiosis lipoídica: otras relacionadas con linfomas, como la micosis fungoides granulomatosa, y otras tan extendidas que casi resultan un problema cotidiano en las consultas de dermatología, como la rosácea (AU)

This series of 2 articles on dermatopathologic diagnoses reviews conditions in which granulomas form. Part 1 clarifies concepts, discusses the presentation of different types of granulomas and giant cells, and considers a large variety of noninfectious diseases. Some granulomatous diseases have a metabolic origin, as in necrobiosis lipoidica. Others, such as granulomatous mycosis fungoides, are related to lymphomas. Still others, such as rosacea, are so common that dermatologists see them nearly daily in clinical practice (AU)

Granulomas en dermatopatología: principales entidades. Parte II / Granulomas in Dermatopathology: Principal Diagnoses — Part 2

Esta es la segunda parte de una serie dedicada a la patología granulomatosa en la biopsia cutánea. Mientras que en la primera parte hablamos, entre otras, de algunas condiciones metabólicas y tumorales, esta segunda parte abordará fundamentalmente patología infecciosa de diversos tipos, junto con otras condiciones relativamente frecuentes en las consultas de dermatología (AU)

Part 2 of this series on granulomatous diseases focuses on skin biopsy findings. Whereas the first part treated noninfectious conditions (metabolic disorders and tumors, among other conditions), this part mainly deals with various types of infectious disease along with other conditions seen fairly often by clinical dermatologists (AU)