Mycosis Fungoides and Sézary Syndrome: Microenvironment and Cancer Progression

Advances in the pharmacological management of cutaneous T-cell lymphoma

INTRODUCTION

Current treatment guidelines for cutaneous T cell lymphoma (CTCL) advocate a stage-driven approach, considering clinical presentation, symptom burden, and patient comorbidities. Therapy selection hinges on factors like disease subtype, severity, and treatment availability. The primary goal is to enhance the quality of life by mitigating symptoms, as achieving lasting complete remission is infrequent.

AREAS COVERED

Over the past decade (2013-2023), the therapeutic landscape of CTCL has experienced substantial transformation with the introduction of innovative therapies. This review explores the main pivotal developments in traditional treatment schedules and recently introduced drugs, aiming to offer clinicians and researchers a thorough perspective on the decade's progress in the field.

EXPERT OPINION

Despite the progress made in CTCL therapeutics, ranging from topical chemotherapeutics to immunomodulatory agents, several unmet needs persist. Firstly, there is a pressing need for the incorporation of readily available predictors for treatment response, encompassing clinical, pathological, and molecular features. Secondly, a more profound comprehension of the tumor microenvironment is imperative to optimize the landscape of targetable molecules. Lastly, the undertaking of studies on combination regimens should be encouraged as it enhances therapy efficacies by synergistically combining agents with diverse modes of action.

Pathophysiology of cutaneous T-cell lymphomas: Perspective from a French referral centre

Cutaneous T-cell lymphomas (CTCL) are a diverse group of malignant blood disorders characterized by initial skin infiltration, and sometimes, tumor spreading to lymph nodes, blood, and viscera. Mycosis fungoides is the most common form. Sézary syndrome is a distinctive form of CTCL marked by a significant presence of circulating tumor cells in peripheral blood. These diseases are characterized by the plasticity and heterogeneity of the tumor cells in the different tissue compartments, and a difficulty in identifying these tumor cells for diagnostic purposes and therapeutic monitoring. Progress has been made in the understanding of the pathophysiology of these diseases in recent years, and we provide here a review of these advancements.

The Role of Cytokines in Cutaneous T Cell Lymphoma: A Focus on the State of the Art and Possible Therapeutic Targets

Cutaneous T cell lymphomas (CTCLs), encompassing mycosis fungoides (MF) and Sézary syndrome (SS), present a complex landscape influenced by cytokines and cellular responses. In this work, the intricate relationship between these inflammatory proteins and disease pathogenesis is examined, focusing on what is known at the clinical and therapeutic levels regarding the most well-known inflammatory mediators. An in-depth look is given to their possible alterations caused by novel immunomodulatory drugs and how they may alter disease progression. From this narrative review of the actual scientific landscape, Interferon-gamma (IFN-γ) emerges as a central player, demonstrating a dual role in both promoting and inhibiting cancer immunity, but the work navigates through all the major interleukins known in inflammatory environments. Immunotherapeutic perspectives are elucidated, highlighting the crucial role of the cutaneous microenvironment in shaping dysfunctional cell trafficking, antitumor immunity, and angiogenesis in MF, showcasing advancements in understanding and targeting the immune phenotype in CTCL. In summary, this manuscript aims to comprehensively explore the multifaceted aspects of CTCL, from the immunopathogenesis and cytokine dynamics centred around TNF-α and IFN-γ to evolving therapeutic modalities. Including all the major known and studied cytokines in this analysis broadens our understanding of the intricate interplay influencing CTCL, paving the way for improved management of this complex lymphoma.

Differential Upregulation of Th1/Th17-Associated Proteins and PD-L1 in Granulomatous Mycosis Fungoides

Granulomatous Mycosis Fungoides (GMF) is a rare form of mycosis fungoides (MF) characterized by a granulomatous infiltrate associated with the neoplastic lymphoid population and is considered to have a worse prognosis compared with regular MF. The upregulation of the T helper (Th) axis, especially Th17, plays an important role in the pathogenesis of several inflammatory/infectious granulomatous cutaneous diseases, but its role in GMF is still not elucidated to date. In this study, we evaluated the immunohistochemical expression of Th1 (Tbet), Th2 (GATA-3), Th17 (RORγT), T regulatory (Foxp3), and immune checkpoint (IC) (PD-1 and PD-L1) markers in a cohort of patients with GMF and MF with large cell transformation (MFLCT). Skin biopsies from 49 patients (28 GMF and 21 MFLCT) were studied. Patients with GMF were associated with early clinical stage (p = 0.036) and lower levels of lactate dehydrogenase (p = 0.042). An increased percentage of cells positive for Tbet (p = 0.017), RORγT (p = 0.001), and PD-L1 (p = 0.011) was also observed among the GMF specimens, while a stronger PD-1 intensity was detected in cases of MFLCT. In this cohort, LCT, RORγT < 10%, Foxp3 < 10%, age, and advanced stage were associated with worse overall survival (OS) in univariate analysis. GMF demonstrated Th1 (cellular response) and Th17 (autoimmunity) phenotype, seen in early MF and granulomatous processes, respectively, which may be related to the histopathological appearance and biological behavior of GMF. Further studies involving larger series of cases and more sensitive techniques are warranted.

Identification of Skin Lesions by Snapshot Hyperspectral Imaging

This study pioneers the application of artificial intelligence (AI) and hyperspectral imaging (HSI) in the diagnosis of skin cancer lesions, particularly focusing on Mycosis fungoides (MF) and its differentiation from psoriasis (PsO) and atopic dermatitis (AD). By utilizing a comprehensive dataset of 1659 skin images, including cases of MF, PsO, AD, and normal skin, a novel multi-frame AI algorithm was used for computer-aided diagnosis. The automatic segmentation and classification of skin lesions were further explored using advanced techniques, such as U-Net Attention models and XGBoost algorithms, transforming images from the color space to the spectral domain. The potential of AI and HSI in dermatological diagnostics was underscored, offering a noninvasive, efficient, and accurate alternative to traditional methods. The findings are particularly crucial for early-stage invasive lesion detection in MF, showcasing the model's robust performance in segmenting and classifying lesions and its superior predictive accuracy validated through k-fold cross-validation. The model attained its optimal performance with a k-fold cross-validation value of 7, achieving a sensitivity of 90.72%, a specificity of 96.76%, an F1-score of 90.08%, and an ROC-AUC of 0.9351. This study marks a substantial advancement in dermatological diagnostics, thereby contributing significantly to the early and precise identification of skin malignancies and inflammatory conditions.