Immunobiology and treatment of cutaneous T-cell lymphoma

INTRODUCTION

Primary cutaneous T cell lymphomas (CTCL) are a heterogenous group of non-Hodgkin lymphomas derived from skin-homing T cells. These include mycosis fungoides and its leukemic variant Sezary syndrome, as well as the CD30+ lymphoproliferative disorders.

AREAS COVERED

In this review, we provide a summary of the current literature on CTCL, with a focus on the immunopathogenesis and treatment of mycosis fungoides and Sezary syndrome.

EXPERT OPINION

Recent advances in immunology have provided new insights into the biology of malignant T cells. This in turn has led to the development of new therapies that modulate the immune system to facilitate tumor clearance or target specific aspects of tumor biology.

Evaluation of Quality of Life and Treatment Satisfaction in Newly Diagnosed Cutaneous T-Cell Lymphoma Patients

BACKGROUND

Little is known about the impact of MF on quality of life (QoL) in newly diagnosed patients.

OBJECTIVES

To describe the impact of the MF diagnosis on QoL, patient expectations, and treatment satisfaction over the first 6 months after diagnosis.

METHODS

Outcomes of this prospective cohort study of newly diagnosed MF patients conducted between 2020 and 2022 at the Leiden University Medical Center included the Skindex-29, RAND-12 Health Survey, degree of itch, pain, and fatigue (Visual Analogue Scale (VAS)), patient expectations, and Client Satisfaction Questionnaire-8 (CSQ-8), measured at baseline and after six months.

RESULTS

A total of 28 patients with MF were included. At baseline, 66% (n = 18) "strongly-totally" expected positive effects of the treatment. At the time of diagnosis, 28% of the patients (n = 8) were moderately to severely affected. There was no statistical change in the Skindex-29 score sum score (20 [10-34] vs. 20 [9-36]; p = 0.81) or in the other three subdomains, the RAND-12 scores, and the VAS itch, pain, and fatigue over time. Treatment satisfaction was high overall.

CONCLUSION

Despite that the newly diagnosed MF patients anticipate a positive treatment effect, few improvements in QoL and symptom reduction were found. These data can be used for adequate expectation management and provide a rationale for further evaluation of treatment regimens in these patients.

Role of IL-4 and IL-13 in Cutaneous T Cell Lymphoma

The interleukins IL-4 and IL-13 are increasingly recognized contributors to the pathogenesis of cutaneous T cell lymphomas (CTCLs), and their role in disease-associated pruritus is accepted. The prevailing Th2 profile in advanced CTCL underscores the significance of understanding IL-4/IL-13 expression dynamics from the early stages of disease, as a shift from Th1 to Th2 may explain CTCL progression. Targeted agents blocking key cytokines of type 2 immunity are established therapeutics in atopic disorders and have a promising therapeutic potential in CTCL, given their involvement in cutaneous symptoms and their contribution to the pathogenesis of disease. IL-4, IL-13, and IL-31 are implicated in pruritus, offering therapeutic targets with dupilumab, tralokinumab, lebrikizumab, and nemolizumab. This review analyzes current knowledge on the IL-4/IL-13 axis in mycosis fungoides and Sezary syndrome, the most common types of CTCL, examining existing literature on the pathogenetic implications with a focus on investigational treatments. Clinical trials and case reports are required to shed light on novel uses of medications in various diseases, and ongoing research into the role of IL-4/IL-13 axis blockers in CTCL therapy might not only improve the management of disease-related pruritus but also provide in-depth insights on the pathophysiologic mechanisms of CTCL.

Chemical exposures and demographic associations in cutaneous T-cell lymphoma: a large single institution physician validated cohort study

Cutaneous T-cell lymphomas (CTCL) are a rare group of T-cell neoplasms which infiltrate the skin and can result in substantial morbidity and mortality. Risk factors for CTCL are still poorly understood though recent studies suggest chemical exposures may play a role in its development. To further characterize patient-centered risk factors for CTCL, especially compared with matched controls, we performed one of the largest prospective cohort survey studies to date to examine patient-reported exposures and health-related quality of life (HRQoL) in association with concurrent clinical disease characteristics. Patient demographics, lifestyle factors, and chemical exposures were collected via clinical data and surveys. Descriptive statistics, ANOVA, Chi-square tests and t tests were utilized to compare patient-reported exposures and HRQoL in patients with CTCL versus matched healthy controls (HC). Statistically significant differences were identified between patients and HC in terms of race (non-white race 22.4% in CTCL patients vs. 18.8% in HC, P = 0.01), and education level (high school or less 41.6% in CTCL patients vs. 14.3% in HC, P = 0.001), but not with Fitzpatrick skin type (P = 0.11) or smoking status (P = 0.28). Notably, 36.0% of the CTCL patients reported exposures to chemicals, a near threefold increased percentage when compared to HC (12.9%). Among various chemical exposures, 27.0% of the CTCL patients specifically reported industrial chemical exposure, a more than two-fold increased percentage when compared to HC (12.9%). Itch and pain were significantly associated with skin disease severity (as evaluated by CTCL-specific mSWAT score) in advanced stage disease (stages IIB-IVB) (r = 0.48 and 0.57, P < 0.05). Itch and body mass index (BMI) were weakly associated with skin disease severity in early-stage disease (stages IA-IIA) (r = 0.27 and 0.20, P < 0.05).

Allogeneic transplantation and cellular therapies in cutaneous T-cell lymphoma

INTRODUCTION

Mycosis fungoides (MF) and Sezary syndrome (SS) are the most common types of cutaneous T-cell lymphoma. Although many available treatments offer temporary disease control, allogeneic hematopoietic stem cell transplant (allo-HSCT) is the only curative treatment option for advanced stage MF and SS. CAR T-cell therapy is a promising new avenue for treatment.

AREAS COVERED

In this review, we discuss the evidence supporting the use of allo-HSCT for the treatment of MF/SS, including disease status at the time of transplant, conditioning regimen, total body irradiation (TBI), and donor lymphocyte infusion (DLI). We also address the potential role for CAR T-cell therapy in CTCL.

EXPERT OPINION

Allo-HSCT is an effective treatment for patients with advanced MF and SS. However, significant research is required to determine optimal treatment protocols. Data support the use of reduced-intensity conditioning regimens and suggests that the use of TBI for debulking of skin disease may result in more durable remissions. Donor lymphocyte infusions (DLI) appear to be particularly effective in inducing complete remission in MF/SS patients with relapsed or residual disease. Challenges with CAR-T therapies in T-cell lymphoma include T-cell fratricide due to shared antigens on malignant and nonmalignant T-cells, penetrance into the skin compartment, and CAR-T cell persistence.

Cutaneous T-cell lymphoma with CNS involvement: a case series and review of the literature

Cutaneous T-cell lymphoma (CTCL) is a rare hematologic malignancy that traditionally presents with cutaneous lesions, though metastases are not uncommon in progressive disease. We describe four cases of CTCL with central nervous system (CNS) involvement, detailing the history, pathological characteristics, treatment response, and progression. Median time from initial diagnosis to CNS metastasis was ∼5.4 years (range 3.4-15.5 years) and survival after metastasis was ∼160 days (range 19 days-4.4 years). No patients achieved long-term (>5 years) survival, though some displayed varying degrees of remission following CNS-directed therapy. We conclude that clinicians must be attentive to the development of CNS metastases in patients with CTCL. The growing body of literature on such cases will inform evolving therapeutic guidelines on this rare CTCL complication.

High-throughput RNA sequencing of the T cell receptor alpha and beta chains for simultaneous clonality and biological analyses in Sezary syndrome

BACKGROUND

Previous investigations pointed out a role for antigen stimulation in Sezary syndrome (SS). High-throughput sequencing of the T cell receptor (TR) offers several applications beyond diagnostic purposes, including the study of T cell pathogenesis.

METHODS

We performed high-throughput RNA sequencing of the TR alpha (TRA) and beta (TRB) genes focusing on the complementarity-determining region 3 (CDR3) in 11 SS and one erythrodermic mycosis fungoides (MF) patients. Five psoriasis patients were employed as controls. Peripheral blood CD4+ cells were isolated and RNA sequenced (HiSeq2500). High-resolution HLA typing was performed in neoplastic patients.

RESULTS

Highly expanded predominant TRA and TRB CDR3 were only found in SS patients (median frequency: 94.4% and 93.7%). No remarkable CDR3 expansions were observed in psoriasis patients (median frequency of predominant TRA and TRB CDR3: 0.87% and 0.69%, p < 0.001 compared to SS). CDR3 almost identical to the predominant were identified within each SS patient and were exponentially correlated with frequencies of the predominant CDR3 (R2  = 0.918, p < 0.001). Forty-six different CDR3 were shared between SS patients displaying HLA similarities, including predominant TRA and TRB CDR3 in one patient that were found in other three patients. Additionally, 351 antigen matches were detected (Cytomegalovirus, Epstein-Barr, Influenza virus, and self-antigens), and the predominant CDR3 of two different SS patients matched CDR3 with specificity for Influenza and Epstein-Barr viruses.

CONCLUSIONS

Besides detecting clonality, these findings shed light on the nature of SS-related antigens, pointing to RNA sequencing as a useful tool for simultaneous clonality and biological analysis in SS.

Clinicopathologic Features of Cutaneous T-Cell Lymphomas With Extracutaneous Metastasis: A Case Series

BACKGROUND

In advanced stages, Cutaneous T-cell lymphomas (CTCL) can metastasize to extracutaneous regions. CTCL with metastasis exhibits unique clinicopathologic characteristics.

PATIENTS AND METHODS

This study collected 35 cases of primary CTCL with extracutaneous metastasis from a single institution over a period of 20 years. Clinicopathologic features including demographics, CD30 expression, large cell transformation, metastatic sites, T-cell receptor clonality studies and survival data were analyzed.

RESULTS

The study identified various CTCL entities including mycosis fungoides (MF), Sezary syndrome (SS), cutaneous anaplastic large cell lymphoma (C-ALCL), and primary cutaneous peripheral T-cell lymphoma, not otherwise specified (pcPTCL-NOS). Limited data showed that metastasis can be independent of large cell transformation and/or CD30 expression. Lymph nodes were the most common site of metastasis, followed by the bone marrow. Oropharyngeal metastasis is likely to accompany visceral organ or brain metastasis (P = .049). MF had a longer interval to metastasis than SS (P = .038). Patients with lymph node only metastasis have better survival than patients with metastasis to other sites (P = .012).

CONCLUSION

To the best of our knowledge, there are limited studies analyzing the clinicopathologic features of different CTCL entities with metastasis as a single population. This research provides valuable insights into the unique characteristics of metastatic CTCL.

Dupilumab-associated mycosis fungoides: a cross-sectional study

Treating atopic dermatitis (AD) with dupilumab, a monoclonal antibody that inhibits interleukin-4 (IL-4) and interleukin-13 (IL-13), may be associated with the progression of mycosis fungoides (MF).This study aims to examine the associations between the length of dupilumab treatment, age and sex, and the onset of MF.An institutional data registry and literature search were used for a retrospective cross-sectional study. Only patients with a diagnosis of MF on dupilumab for the treatment of AD and eczematous dermatitis were included.The primary outcome was the length of dupilumab exposure, age, sex, and the onset of MF. Linear correlations (Pearson) and Cox regression analysis were used to assess the correlation and the risk.A total of 25 patients were included in this study. Five eligible patients were identified at our institution. In addition, a PubMed review identified an additional 20 patients. At the time of MF diagnosis, the median age was 58, with 42% female. Disease history was significant for adult-onset AD in most patients (n = 17, 65.4%) or recent flare of AD previously in remission (n = 3, 11.5%). All patients were diagnosed with MF, and one patient progressed to Sézary syndrome while on dupilumab, with an average duration of 13.5 months of therapy prior to diagnosis. Tumor stage at diagnosis of MF was described in 19 of the cases and ranged from an early-stage disease (IA) to advanced disease (IV). Treatment strategies included narrow-band UVB therapy, topical corticosteroids, brentuximab, pralatrexate, and acitretin. Male gender, advanced-stage disease, and older age correlated significantly with the hazard of MF onset and a shorter time to onset during dupilumab treatment.Our results suggest a correlation between the duration of dupilumab treatment and the diagnosis of MF, the higher MF stage at diagnosis, and the shorter the duration of using dupilumab to MF onset. Furthermore, elderly male patients appeared to be more at risk as both male gender and older age correlated with a hazard of MF diagnosis. The results raise the question as to whether the patients had MF misdiagnosed as AD that was unmasked by dupilumab or if MF truly is an adverse effect of treatment with dupilumab. Close monitoring of these patients and further investigation of the relationship between dupilumab and MF can shed more light on this question .

Microenvironment-dependent growth of Sezary cells in humanized IL-15 mice

Sezary syndrome (SS) is a rare, aggressive leukemic variant of cutaneous T-cell lymphoma (CTCL) that lacks adequate therapeutic options and representative small-animal models. Here, we demonstrate that IL-15 is a critical CTCL growth factor. Importantly, an immunodeficient knock-in mouse model genetically engineered to express human IL-15 uniquely supported the growth of SS patient samples relative to conventional immunodeficient mouse strains. SS patient-derived xenograft (PDX) models recapacitated key pathological features of the human disease, including skin infiltration and spread of leukemic cells to the periphery, and maintained the dependence on human IL-15 upon serial in vivo passaging. Detailed molecular characterization of the engrafted cells by single-cell transcriptomic analysis revealed congruent neoplastic gene expression signatures but distinct clonal engraftment patterns. Overall, we document an important dependence of Sezary cell survival and proliferation on IL-15 signaling and the utility of immunodeficient humanized IL-15 mice as hosts for SS - and potentially other T and NK cell-derived hematologic malignancies - PDX model generation. Furthermore, these studies advocate the thorough molecular understanding of the resultant PDX models to maximize their translational impact.

Non-coding RNAs in the epigenetic landscape of cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is a type of cancer that affects skin, and is characterized by abnormal T-cells in the skin. Epigenetic changes have been found to play a significant role in the development and progression of CTCL. Recently, non-coding RNAs (ncRNAs), such as microRNAs and long non-coding RNAs, have been identified as key players in the regulation of gene expression in CTCL. These ncRNAs can alter the expression of genes involved in cell growth, differentiation, and apoptosis, leading to the development and progression of CTCL. In this review, we summarize the current understanding of the role of ncRNAs in CTCL, including their involvement in DNA methylation, and other biological processes. We also discuss the types of ncRNAs, their role as oncogenic or tumor suppressive, and their putative use as diagnostic and prognostic biomarkers, based on the emerging evidence from laboratory-based as well as patients-based studies. Moreover, we also present the potential targets and pathways affected by ncRNAs. A better understanding of the complex epigenetic landscape of CTCL, including the role of ncRNAs, has the potential to lead to the development of novel targeted therapies for this disease.

Mogamulizumab-Associated Myositis With and Without Myasthenia Gravis and/or Myocarditis in Patients With T-Cell Lymphoma

Mogamulizumab is being increasingly prescribed for the treatment of T-cell lymphomas (MF/SS/ATLL). We conducted a retrospective cohort study to identify muscular immune-related adverse events (irAEs) associated with mogamulizumab in patients with T-cell lymphoma followed at Dana-Farber Cancer Institute from January 2015 to June 2022. We identified 5 cases of mogamulizumab-associated myositis and/or myocarditis (MAM/Mc), 2 additionally affected by myasthenia gravis, among 42 patients with T-cell lymphoma. Three cases experienced -mogamulizumab-associated rash (MAR) prior to developing MAM/Mc. The incidence (n = 5/42, 11.9%) of muscular mogamulizumab-associated irAEs may be higher than has been previously reported in clinical trials and may be of late onset (a median of 5 cycles and as late as 100 days from the last infusion). We highlight the utility of IVIG, together with systemic corticosteroids, for the treatment of these potentially fatal side effects associated with mogamulizumab therapy.

Lifestyle, demographic and Skindex measures associated with cutaneous T-cell lymphoma: a single institution cohort study

Cutaneous T-cell lymphoma (CTCL) risk factors and associated quality of life are poorly understood. Previous studies of CTCL risk factors explored patient comorbidities and lifestyle exposures, but not in conjunction with disease stage, subtype, severity, or health-related quality of life (HRQoL). We investigated lifestyle exposures and demographic factors associated with advanced-stage disease, increased disease severity, and poorer HRQoL outcomes in this single-center cohort study. A cohort survey study was conducted at Northwestern's Multidisciplinary Cutaneous Lymphoma specialty clinic between April 2019 and June 2021. REDCap surveys were administered to 140 patients with CTCL, investigating patients' demographics, lifestyle and chemical exposures. QoL was evaluated using the Skindex survey; pain and itch with ten-point Likert scales. Modified Severity Weighted Assessment Tool (mSWAT), disease stage, and disease subtype were confirmed upon enrollment in the study by a single board-certified dermatologist specializing in CTCL. Factors were compared by t test or Fischer's exact test. Median age was 63 years (range 14-92) with male-to-female ratio of 1.2:1. The most common diagnosis was CD4 + MF (n = 94, 67.1%). Common lifestyle exposures included smoking (past or current) (52.3%) and chemical exposure history (all sources [53.7%]; industrial only [33.0%]). History of chemical exposures were associated with advanced stage disease (p = 0.003) and worse QoL outcomes (p = 0.001). There were significant racial differences, respectively, in early (I-IIA) vs late (IIB-IV) stage disease (p = 0.003). Obesity, hygiene, smoking, recent sun exposure, education and atopy were not significantly associated with disease stage or severity. We provide an analysis of lifestyle and demographic factors in the context of CTCL disease severity, stage, and HRQoL. We identified race as a potential risk factor for advanced stage disease and both skin phototype and chemical exposures as a risk factor for increased disease severity as measured by mSWAT. QoL outcomes were multifactorial and significantly associated with history of chemical exposure, severe pain/itch, race, disease stage and subtype. An improved understanding of these associations may lead to better individualized care. As chemical exposure and race were found to be significant factors associated with advanced-stage disease, taking exposure histories and addressing racial disparities may improve care for CTCL patients.

Staging lymph nodes and blood at diagnosis in mycosis fungoides identifies patients at increased risk of progression to advanced stage: A retrospective cohort study

BACKGROUND

Risk factors for progression to advanced-stage mycosis fungoides (MF) are poorly defined.

METHODS

The authors performed a single-center, retrospective cohort study among patients with MF at an academic medical center from 1990 to 2020 to identify clinical variables associated with progression to advanced-stage MF (stage IIB-IVB), and 388 patients who had a clinicopathologic diagnosis of early stage (IA-IIA) MF were identified from their cutaneous lymphoma database. Baseline clinical characteristics, laboratory values, imaging, and blood flow cytometry or T-cell receptor gene rearrangement (TCR) data were collected. Logistic regression was used to assess risk factors associated with progression.

RESULTS

Overall, 93 of 388 patients (24.0%) progressed to advanced stage. Patients who progressed had an increased risk of death (hazard ratio, 4.50; 95% CI, 2.89-7.00; p < .001). Progression was associated with a higher overall stage at diagnosis, tumor stage, lymph node stage, low-level blood involvement, as measured with TCR data and/or flow cytometry, and elevated lactate dehydrogenase (LDH). Limitations included missing data for LDH, imaging, peripheral blood TCR data, or flow cytometry assessed at diagnosis.

CONCLUSIONS

Staging and baseline laboratory assessments with imaging, peripheral blood flow cytometry, TCR data, and LDH in patients who have newly diagnosed MF may identify those who are at risk for progression to advanced stage.

Molecular pathogenesis of Cutaneous T cell Lymphoma: Role of chemokines, cytokines, and dysregulated signaling pathways

Cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphoproliferative neoplasms that exhibit a wide spectrum of immune-phenotypical, clinical, and histopathological features. The biology of CTCL is complex and remains elusive. In recent years, the application of next-generation sequencing (NGS) has evolved our understanding of the pathogenetic mechanisms, including genetic aberrations and epigenetic abnormalities that shape the mutational landscape of CTCL and represent one of the important pro-tumorigenic principles in CTCL initiation and progression. Still, identification of the major pathophysiological pathways including genetic and epigenetic components that mediate malignant clonal T cell expansion has not been achieved. This is of prime importance given the role of malignant T cell clones in fostering T helper 2 (Th2)-bias tumor microenvironment and fueling progressive immune dysregulation and tumor cell growth in CTCL patients, manifested by the secretion of Th2-associated cytokines and chemokines. Alterations in malignant cytokine and chemokine expression patterns orchestrate the inflammatory milieu and influence the migration dynamics of malignant clonal T cells. Here, we highlight recent insights about the molecular mechanisms of CTCL pathogenesis, emphasizing the role of cytokines, chemokines, and associated downstream signaling networks in driving immune defects, malignant transformation, and disease progression. In-depth characterization of the CTCL immunophenotype and tumoral microenvironment offers a facile opportunity to expand the therapeutic armamentarium of CTCL, an intractable malignant skin disease with poor prognosis and in dire need of curative treatment approaches.

Serum cell-free DNA as a new biomarker in cutaneous T-cell lymphoma

In recent years, circulating cell-free DNA (cfDNA) has received a great attention as a biomarker for various cancers. Many reports have shown that serum cfDNA levels are elevated in cancer patients and their levels correlate with prognosis and disease activity. The aim of this study was to measure serum cfDNA levels in patients with cutaneous T-cell lymphoma (CTCL) and to evaluate their correlations with hematological and clinical findings. Serum cfDNA levels in CTCL patients were significantly higher than those in healthy controls, and their levels gradually increased with the progression of the disease stage. Positive correlations were detected between serum cfDNA levels and those of lactate dehydrogenase, thymus and activation-regulated chemokine and soluble IL-2 receptor as well as neutrophil and eosinophil count in peripheral blood and neutrophil-to-lymphocyte ratio. Furthermore, CTCL patients with higher serum cfDNA levels exhibited a significantly worse prognosis. Taken together, these results suggest the potential of cfDNA as a new biomarker reflecting prognosis and disease activity in CTCL. CfDNA levels may serve as an indicator for considering the intensity and timing of subsequent therapeutic intervention.

CD200 expression on Sezary cells: A valuable tool for flow cytometric assessment of peripheral blood T-cell neoplasms

BACKGROUND

CD200 (OX-2) is a valuable marker in the diagnosis of B-cell neoplasms and is commonly used in the screening panels for assessment of peripheral blood B-cell lymphoproliferative disorders. However, there is limited understanding about CD200 expression in T-cell neoplasms. A previous study has shown that CD200 is expressed on the neoplastic cells of angioimmunoblastic T-cell lymphoma (AITL) by immunohistochemistry, but no study has evaluated CD200 expression in T-cell neoplasms by flow cytometry.

METHODS

We assessed CD200 expression in peripheral blood T-cell lymphoproliferative disorders by retrospective analysis of our institutional flow cytometry screening database over a 6-year period.

RESULTS

In addition to AITL, we identified CD200 expression in a significant number of mycosis fungoides/Sezary syndrome cases (58%, 19 of 33 samples), while most other T-cell neoplasms were negative for CD200. These findings were confirmed by CD200 immunohistochemical staining of tissue specimens from our patient cohort.

CONCLUSIONS

CD200 is commonly expressed on circulating Sezary cells, a feature that can potentially improve the diagnostic value of flow cytometry for assessment of T-cell neoplasms.

PD-1 improves accurate detection of Sezary cells by flow cytometry in peripheral blood in mycosis fungoides/Sezary syndrome

BACKGROUND

Accurate Sezary cell detection in peripheral blood of mycosis fungoides/Sezary syndrome (MF/SS) patients by flow cytometry can be difficult due to overlapping immunophenotypes with normal T cells using standard markers. We assessed the utility of programmed death-1 (PD-1/CD279), a transmembrane protein expressed in some hematopoietic cells, for identification and quantitation of circulating Sezary cells among established markers using flow cytometry.

METHODS

50 MF/SS and 20 control blood samples were immunophenotyped by flow cytometry. Principal component analysis (PCA) assessed contributions of antigens to separation of abnormal from normal T cell populations. PD-1 was assessed over time in blood and bone marrow of available MF/SS cases.

RESULTS

Normal CD4+ T cells showed dim/intermediate to absent PD-1 expression. PD-1 in Sezary cells was informatively brighter (≥1/3 log) than internal normal CD4+ T cells in 39/50 (78%) cases. By PCA, PD-1 ranked 3rd behind CD7 and CD26 in population separation as a whole; it ranked in the top 3 markers in 32/50 (64%) cases and 1st in 4/50 (8%) cases when individual abnormal populations were compared to total normal CD4+ T cells. PD-1 clearly separated Sezary from normal CD4+ T cells in 15/26 (58%, 30% of total) cases with few and subtle alterations of pan-T cell antigens/CD26 and was critical in 6 (12% of total), without which identification and quantification were significantly affected or nearly impossible. PD-1 remained informative in blood/bone marrow over time in most patients.

CONCLUSIONS

PD-1 significantly contributes to accurate flow cytometric Sezary cell assessment in a routine Sezary panel.

Continuous low-dose gemcitabine in primary cutaneous T cell lymphoma: a retrospective study

PURPOSE

the aim of our retrospective study was to evaluate the efficacy of a continuous therapy with a lower dosage of gemcitabine compared to those usually administered in patients with CTCL.

MATERIAL AND METHODS

twenty-two patients received different dosages of gemcitabine. Dosage and schedule of the drug were chosen on the basis of clinical features. Gemcitabine was given at 1000 mg every 15 days in 13 patients (4 MF, 9 SS); at 1000 mg at days +1, +8, +15 in 6 cases (3 MF, 3 SS).

RESULTS

All patients had been previously treated: four patients had received both skin directed and systemic treatments. Eighteen patients had received photopheresis, IFN, chemotherapy and immunotherapy. The Objective Response Rate (CR+PR) among all patients was 54.5% (12 of 22 patients) with a CR of 4.5% (1 of 22 patients) and a PR of 50% (11 of 22 patients). Patients with SS had an ORR of 61.5% (8 of 13 patients) with 1 CR (7%) and 7 PR (53.8%); patients with MF showed an ORR of 55.6% (5 of 9 patients) but no patients experienced CR (0%). The schedule with the highest efficacy and the lowest toxicity profile was 1000 mg every 15 days. Median PFS and OS in all patients were 17 and 45 months respectively. Gemcitabine was generally well tolerated. This article is protected by copyright. All rights reserved.

CONCLUSIONS

we have demonstrated that a much lower dose of gemcitabine (1000 mg once every 15 days) in patients with advanced-stage and refractory CTCL can lead to a durable response, with tolerable and manageable adverse effects. This article is protected by copyright. All rights reserved.

Allogeneic Hematopoietic Stem Cell Transplantation For Heavily Pretreated Patients With Mycosis Fungoides and Sezary Syndrome

Allogeneic hematopoietic stem cell transplantation (AHSCT) is a promising strategy for treatment of heavily pretreated mycosis fungoides/Sezary syndrome (MF/SS). Herein, we aimed to evaluate the outcomes of AHSCT for heavily pretreated patients with MF/SS retrospectively. This analysis included consecutive 19 patients with MF/SS who received 20 AHSCT between 2012-2021 in our transplant center. Eight patients have been previously reported. Fifteen patients had diagnosis of MF and referred to SS in five patients. In our cohort, all cases had advanced disease (stages IIB: n = 1, IIIA: n = 7; IIIB: n = 4, IVA: n = 4, IVB: n = 3). Nine patients (47.4%) had developed large cell transformation. Only two patients received AHSCT in complete response (CR), one very good partial response (VGPR) and two partial response (PR) while the others had progressive disease (PD) (n = 15) before transplant. Seven (35%) patients were alive at the time of analysis, with a median follow up of 10.5 months (range, 0.3-113 months) after AHSCT. Nine patients (47.4%) died without disease relapse or progression. NRM was 35.9% at 1 year and 26.9% at 3 years and therafter. For all patients the probability of OS was 48.5% and 32.3% at 1- and 5- year post-transplant, respectively. AHSCT for MF/SS resulted in an estimated PFS of 45.4% at 1 year. Given the poor prognosis of patients not receiving transplants and in the absence of curative non-transplantation therapies, our results support that AHSCT is able to effectively rescue 32.3% of the population of transplant eligible, heavily pretreated patients in 5 years. This article is protected by copyright. All rights reserved.

The Role of Tumor Microenvironment in Mycosis Fungoides and Sézary Syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are the most common subtypes of cutaneous T-cell lymphomas (CTCLs). Most cases of MF display an indolent course during its early stage. However, in some patients, it can progress to the tumor stage with potential systematic involvement and a poor prognosis. SS is defined as an erythrodermic CTCL with leukemic involvements. The pathogenesis of MF and SS is still not fully understood, but recent data have found that the development of MF and SS is related to genetic alterations and possibly to environmental influences. In CTCL, many components interacting with tumor cells, such as tumor-associated macrophages, fibroblasts, dendritic cells, mast cells, and myeloid-derived suppressor cells, as well as with chemokines, cytokines and other key players, establish the tumor microenvironment (TME). In turn, the TME regulates tumor cell migration and proliferation directly and indirectly and may play a critical role in the progression of MF and SS. The TME of MF and SS appear to show features of a Th2 phenotype, thus dampening tumor-related immune responses. Recently, several studies have been published on the immunological characteristics of MF and SS, but a full understanding of the CTCL-related TME remains to be determined. This review focuses on the role of the TME in MF and SS, aiming to further demonstrate the pathogenesis of the disease and to provide new ideas for potential treatments targeted at the microenvironment components of the tumor.

The Microenvironment's Role in Mycosis Fungoides and Sézary Syndrome: From Progression to Therapeutic Implications

BACKGROUND

Mycosis fungoides (MF) and Sezary Syndrome (SS) are the most common cutaneous T-cell lymphomas. It has been hypothesized that the interaction between the immune system, cutaneous cells, and neoplastic elements may play a role in MF/SS pathogenesis and progression.

METHODS

This paper aims to revise in a narrative way our current knowledge of the microenvironment's role in MF/SS.

RESULTS AND CONCLUSIONS

Literature data support a possible implication of microenvironment cells in MF/SS pathogenesis and progression, opening up new therapeutic avenues.

New nonchemotherapy treatment options for cutaneous T-cell lymphomas

INTRODUCTION

The most common types of CTCL are mycosis fungoides (MF) and Sézary syndrome (SS). In both MF and SS, complete responses to treatment are uncommon. Recent developments and understanding of the biology of MF/SS have led to novel agents which may offer prolonged responses with less toxicity compared to conventional chemotherapy approaches.

AREAS COVERED

In this review, we discuss the efficacy and safety of new nonchemotherapy treatment options including antibody agents, small molecule inhibitors, fusion proteins, and CAR T-cell therapy. We also reflect on older immunomodulatory treatments including retinoids and histone deacetylase inhibitors.

EXPERT OPINION

Patients with MF/SS who require systemic therapy often progress through multiple agents sequentially, thus the need for additional novel agents in the treatment armamentarium. Antibody-based therapies such as alemtuzumab are highly effective in the blood compartment of disease, while brentuximab vedotin has shown higher activity in skin and lymph nodes. Checkpoint inhibitors may play a role in treating MF/SS but may induce hyperprogression, and engineered T cells and bispecific antibodies recruiting immune effectors are being developed and may show promise in the future.

Mycosis fungoides and Sézary syndrome: focus on the current treatment scenario

Cutaneous T-cell lymphomas are a heterogeneous group of lymphoproliferative disorders, characterized by infiltration of the skin by mature malignant T cells. Mycosis fungoides is the most common form of cutaneous T-cell lymphoma, accounting for more than 60% of cases. Mycosis fungoides in the early-stage is generally an indolent disease, progressing slowly from some patches or plaques to more widespread skin involvement. However, 20% to 25% of patients progress to advanced stages, with the development of skin tumors, extracutaneous spread and poor prognosis. Treatment modalities can be divided into two groups: skin-directed therapies and systemic therapies. Therapies targeting the skin include topical agents, phototherapy and radiotherapy. Systemic therapies include biological response modifiers, immunotherapies and chemotherapeutic agents. For early-stage mycosis fungoides, skin-directed therapies are preferred, to control the disease, improve symptoms and quality of life. When refractory or in advanced-stage disease, systemic treatment is necessary. In this article, the authors present a compilation of current treatment options for mycosis fungoides and Sézary syndrome.

CCR4 in cutaneous T-cell lymphoma: Therapeutic targeting of a pathogenic driver

New treatments are needed for patients with cutaneous T-cell lymphoma (CTCL), particularly for advanced mycosis fungoides (MF) and Sezary syndrome (SS). The immunopathology of MF and SS is complex, but recent advances in tumor microenvironment understanding have identified CCR4 as a promising therapeutic target. CCR4 is widely expressed on malignant T cells and Tregs in the skin and peripheral blood of patients with MF and SS. The interaction of CCR4 with its dominant ligands CCL17 and CCL22 plays a critical role in the development and progression of CTCL, facilitating the movement into, and accumulation of, CCR4-expressing T cells in the skin, and recruiting CCR4-expressing Tregs into the tumor microenvironment. Expression of CCR4 is upregulated at all stages of MF and in SS, increasing with advancing disease. Several CCR4-targeted therapies are being evaluated, including "chemotoxins" targeting CCR4 via CCL17, CCR4-directed chimeric antigen receptor-modified T-cell therapies, small-molecule CCR4 antagonists, and anti-CCR4 monoclonal antibodies. Only one is currently approved: mogamulizumab, a defucosylated, fully humanized, anti-CCR4, monoclonal antibody for the treatment of relapsed/refractory MF and SS. Clinical trial da1ta confirm that mogamulizumab is an effective and well-tolerated treatment for relapsed/refractory MF or SS, demonstrating the clinical value of targeting CCR4.

Part II: Prognosis and Management

Primary cutaneous T-cell lymphomas (CTCLs) other than Mycosis Fungoides (MF) and Sézary syndrome (SS) encompass a heterogenous group of non-Hodgkin lymphomas with variable clinical course, prognoses, and management. With morphologic and histologic overlap among the CTCL subtypes and other T-cell lymphomas with cutaneous manifestations, thorough evaluation with clinicopathologic correlation and exclusion of systemic involvement are essential prior to initiating therapy. Staging and treatment recommendations vary depending on the subtype, clinical behavior, and treatment response. Generally, for subtypes where staging is recommended, Ann Arbor or TNM staging specific to CTCL other than MF or SS are used. For many subtypes, there is no standard treatment to date. Available recommended treatments range widely from no active or minimal intervention with skin-directed therapy to aggressive systemic therapies including multiagent chemotherapy with consideration for hematopoietic stem cell transplant. Emerging targeted therapies, such as brentuximab, a chimeric antibody targeting CD30, show promise in altering the disease course of non-MF/SS CTCLs.

Primary cutaneous T-cell lymphomas other than Mycosis Fungoides and Sezary Syndrome - Part I: Clinical and histologic features and diagnosis

Primary cutaneous T-cell lymphomas (CTCLs) are defined as lymphomas with a T-cell phenotype that present in the skin without evidence of systemic or extracutaneous disease at initial presentation. CTCLs other than Mycosis Fungoides (MF) and Sézary syndrome (SS) account for approximately one-third of CTCLs and encompass a heterogenous group of non-Hodgkin lymphomas ranging from indolent lymphoproliferative disorders to aggressive malignancies with a poor prognosis. The spectrum of CTCLs continues to broaden as new provisional entities are classified. Given the morphologic and histologic overlap among CTCLs and other diagnoses, a thorough clinical history, physical evaluation, and clinicopathologic correlation are essential in the workup and diagnosis of these rare entities. This article will summarize the epidemiologic, clinical, pathologic, and diagnostic features of CTCLs other than MF and SS.

Perphenazine exerts antitumor effects on HUT78 cells through Akt dephosphorylation by protein phosphatase 2A

Sezary syndrome is a rare type of non-Hodgkin lymphoma. Protein phosphatase 2A (PP2A) is an important tumor suppressor whose activity is widely inhibited in a variety of tumors. Recently, reactivation of PP2A has attracted increasing attention as a promising approach for cancer therapy. Phenothiazine anti-psychotic perphenazine (PPZ) exerts antitumor effects by reactivating PP2A. The present study investigated the molecular mechanism underling the antitumor effects of PPZ in the neuroblastoma rat sarcoma oncogene (NRAS)-mutated Sezary syndrome cell line, HUT78. The results of the present study demonstrated that PPZ induced the dephosphorylation of Akt and ERK1/2, and triggered apoptosis in HUT78 cells. In addition, a PP2A inhibitor blocked the PPZ-mediated dephosphorylation of Akt but did not affect that of ERK1/2. The pharmacological inhibition of Akt and ERK1/2 signaling revealed that Akt activity serves an important role in the survival of HUT78 cells. The present data suggested that suppressing Akt activity by PP2A activation may be an attractive antitumor strategy for NRAS-mutated Sezary syndrome.

T-cell and NK-cell lymphomas in the lung

While the lung is frequently involved by systemic lymphoma, primary pulmonary lymphoma accounts for less than 1% of all extranodal ymphomas. In particular, T-cell lymphoma is very rare in the lung, as a primary or secondary lesion. Patients with pulmonary T-cell lymphoma usually present with cough, dyspnea, pain, fever, recurrent infections, and hemoptysis. Typical radiologic features include pulmonary nodules, consolidation, solid pulmonary opacities, cystic changes, hilar adenopathy, and pleural effusions. Patients with these clinical and radiologic findings are frequently presumed to have pneumonia and initially treated with empirical antibiotics. Therefore, CT-guided needle biopsy, bronchoscopic examination, or even wedge biopsy should be considered when clinical symptoms show deterioration despite adequate antibiotic therapy. Precise pathologic diagnosis and molecular characterization are recommended in all cases, following the World Health Organization (WHO) classification. Principles of treatment typically vary with the different histologic types of T-cell lymphoma.

[Cutaneous lymphomas : Clinical presentation - diagnosis - treatment]

Cutaneous lymphomas comprise different subgroups with distinct biological behavior. Mycosis fungoides, the most common cutaneous lymphoma, presents with patches, plaques, tumors and erythroderma. Therapeutic options depend on stage and comprise local skin-directed treatment in early stages, while later stages and Sézary syndrome require systemic therapies including bexarotene, interferon or brentuximab vedotin. While the rare CD4-positive lymphoproliferation and acral CD8-positive lymphoma present with an invariably indolent course, cutaneous peripheral T‑cell lymphomas exhibit an aggressive clinical behavior. Among the subgroup of cutaneous B‑cell lymphomas, primary cutaneous marginal zone lymphoma and follicle center cell lymphoma belong to indolent entities with almost unrestricted overall survival, whereas cutaneous large B‑cell lymphoma presents with a significant risk of systemic dissemination and is associated with high lethality.

Lack of Durable Remission with Conventional-Dose Total Skin Electron Therapy for the Management of Sezary Syndrome and Multiply Relapsed Mycosis Fungoides

Mycosis fungoides (MF) and Sezary syndrome (SS) are multi-relapsing, morbid, cutaneous T-cell lymphomas. Optimal treatment sequencing remains undefined. Total skin electron therapy (TSE) is a highly technical, skin-directed treatment, uniquely producing symptom-free and treatment-free intervals. Recent publications favour low-dose TSE for reduced toxicity, but early data support conventional-dose TSE (cdTSE) for longer disease control. Patient selection requires weighing-up tolerability against response durability. We investigated duration of benefit from cdTSE in patients with poorer prognosis diseases: SS and heavily pre-treated MF. Endpoints were overall survival, and “time to next treatment” (TTNT) as surrogate for clinical benefit duration. Seventy patients (53 MF, 17 SS) were eligible: median prior treatments, 4; median cdTSE dose, 30 Gy; median follow-up, 5.8 years. SS patients had worse prognosis (HR = 5.0, p < 0.001) and shorter TTNT (HR = 4.5, p < 0.001) than MF patients; median TTNT was only 3.7 months. Heavily pre-treated MF patients had inferior prognosis (HR = 1.19 per additional line, p = 0.005), and shorter TTNT (HR = 1.13 per additional line, p = 0.031). Median TTNT for MF patients with ≥3 prior treatments was 7.1 months, versus 23.2 months for 0–2 prior treatments. In conclusion, cdTSE has a limited role in SS. TTNT is reduced in heavily pre-treated MF patients, suggesting greater benefit when utilized earlier in treatment sequencing.

[Cutaneous lymphomas : Clinical presentation - diagnosis - treatment]

Cutaneous lymphomas comprise different subgroups with distinct biological behavior. Mycosis fungoides, the most common cutaneous lymphoma, presents with patches, plaques, tumors and erythroderma. Therapeutic options depend on stage and comprise local skin-directed treatment in early stages, while later stages and Sézary syndrome require systemic therapies including bexarotene, interferon or brentuximab vedotin. While the rare CD4-positive lymphoproliferation and acral CD8-positive lymphoma present with an invariably indolent course, cutaneous peripheral T‑cell lymphomas exhibit an aggressive clinical behavior. Among the subgroup of cutaneous B‑cell lymphomas, primary cutaneous marginal zone lymphoma and follicle center cell lymphoma belong to indolent entities with almost unrestricted overall survival, whereas cutaneous large B‑cell lymphoma presents with a significant risk of systemic dissemination and is associated with high lethality.

[Primary cutaneous lymphoma-a case series of 163 patients]

BACKGROUND

In addition to a broad and clinically diverse spectrum of known primary cutaneous lymphomas, for which an incidence of 1-3:100,000 is postulated, each year further entities are specified and defined. The goal is the presentation of a case series from daily clinical routine.

METHODS

Over a period of 6 years and 2 months, patients consulting the Department of Dermatology, Medical Center University of Freiburg, were registered. Subsequently, collectives of mycosis fungoides (MF), Sezary syndrome (SS), CD30+ lymphoproliferative diseases, single cases with rare primary cutaneous lymphomas, and subcollectives of B‑cell lymphomas were examined. The high number of MF cases allowed the additional quantitative analyses of the types of therapies used in this group.

RESULTS

Yearly 16-25 new diagnoses of primary cutaneous lymphoma are made. The evaluation of 163 primary cutaneous lymphoma revealed 111 cases with MF (68.1%), including 9 particular variants, 15 primary cutaneous CD30+ lymphoproliferative diseases (9.2%) dominated by 10 lymphomatoid papulosis (LyP), in addition to 5 primary cutaneous anaplastic large cell lymphoma (PCALCL), 6 SS (3.68%), and 24 cutaneous B‑cell lymphomas (14-72%). Three cases with rare primary cutaneous T/NK cell lymphomas are addressed in detail. In all, 82% of MF cases were stage IA and IB. The descending use of therapies for stage I-III included steroids and diverse UV therapies followed by bexarotene, interferon-α, methotrexate, and extracorporal photophoresis.

CONCLUSIONS

Diagnoses of cutaneous lymphomas belong to a vast spectrum of differential diagnoses. This registry describes frequent findings and shows rare variants. You can only diagnose what you know; accordingly, a collection of case reports, which we wish to encourage, can help in processing and specification of entities.

Mogamulizumab: a new tool for management of cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) poses unique treatment challenges, given its range of presentations and numerous systemic therapy options. These options often lack comparative evidence or are characterized by low response rates and short remission duration in relapsed/refractory disease. The approval of mogamulizumab, a humanized, glycoengineered IgG1κ monoclonal antibody targeting the chemokine receptor type 4 (CCR4) chemokine receptor, brings a novel tool into the spectrum of treatment options for advanced CTCL and adult T-cell leukemia/lymphoma (ATLL). CCR4 is expressed in almost all cases of ATLL, and in a majority of CTCLs, particularly when blood involvement is present. In a Phase III randomized trial, mogamulizumab was associated with 28% overall response rate among patients with relapsed CTCL, median progression-free survival of 7.7 months, and median duration of remission of 14.1 months. Responses are more frequent among patients with Sézary syndrome and within the blood compartment. Common adverse effects include rash and infusion reactions, which are usually low grade. Sentinel reports indicate that exposure to mogamulizumab may result in severe or refractory graft vs host disease after allogeneic bone marrow transplantation, highlighting the need for vigilance and expert management. Further research may establish incremental efficacy of combining mogamulizumab with cytotoxic or immunomodulatory agents in CTCL, ATLL, and possibly other lymphomas and even solid tumors.

Molecular and Genomic Landscape of Peripheral T-Cell Lymphoma

Peripheral T-cell lymphoma (PTCL) is an uncommon group of lymphoma covering a diverse spectrum of entities. Little was known regarding the molecular and genomic landscapes of these diseases until recently but the knowledge is still quite spotty with many rarer types of PTCL remain largely unexplored. In this chapter, the recent findings from gene expression profiling (GEP) studies, including profiling data on microRNA, where available, will be presented with emphasis on the implication on molecular diagnosis, prognostication, and the identification of new entities (PTCL-GATA3 and PTCL-TBX21) in the PTCL-NOS group. Recent studies using next-generation sequencing have unraveled the mutational landscape in a number of PTCL entities leading to a marked improvement in the understanding of their pathogenesis and biology. While many mutations are shared among PTCL entities, the frequency varies and certain mutations are quite unique to a specific entity. For example, TET2 is often mutated but this is particularly frequent (70-80%) in angioimmunoblastic T-cell lymphoma (AITL) and IDH2 R172 mutations appear to be unique for AITL. In general, chromatin modifiers and molecular components in the CD28/T-cell receptor signaling pathways are frequently mutated. The major findings will be summarized in this chapter correlating with GEP data and clinical features where appropriate. The mutational landscape of cutaneous T-cell lymphoma, specifically on mycosis fungoides and Sezary syndrome, will also be discussed.

Merkel cell carcinoma arising in association with cutaneous T-cell lymphoma: A potential diagnostic pitfall

Merkel cell carcinoma (MCC) is a rare, aggressive cutaneous neuroendocrine carcinoma with increased prevalence in patients with immunosuppression or B-cell neoplasms. To the best of our knowledge, an association with cutaneous T-cell lymphoma (CTCL) has not been previously described. In this report, we present two cases of MCC arising in the setting of CTCL. The first case was a female during her 70s with previously diagnosed stage IVA1 Sezary syndrome. Biopsy of a scaly patch showed two distinct abnormal cell populations. The first population consisted of hyperchromatic dermal and epidermotropic lymphocytes, expressing CD3 and CD4 with diminished CD7. The second population consisted of intraepidermal clusters of larger atypical cells that expressed synaptophysin, neurofilament, CK20, and Merkel cell polyomavirus transcript. The combination of findings was consistent with intraepidermal MCC in a background of CTCL. Excision showed residual intraepidermal MCC without dermal involvement. The second case was a male during his 50s with a longstanding history of mycosis fungoides, who presented with a new lesion on his right thigh. Biopsy and excision showed dermal MCC without secondary involvement by CTCL. Our cases show that MCC may rarely occur in the setting of T-cell lymphoma, and that intraepidermal MCC may mimic epidermotropic T-cells.

Radiotherapy in Patients with Mycosis Fungoides and Central Nervous System Involvement

Background

Involvement of the central nervous system (CNS) by mycosis fungoides (MF) is rare; however, it portends a poor prognosis. While aggressive multimodality therapy may improve outcomes, the role of radiation therapy (RT) is not well defined.

Objectives

We sought to explore the efficacy of RT in the management of CNS involvement by MF.

Method

We retrospectively identified five patients with MF and CNS involvement who received cranial or craniospinal RT at a single institution. Patient characteristics, disease features, radiographic findings, treatments delivered, and outcome data were extracted from the electronic medical record.

Results

All 5 patients had neurologic deficits at RT initiation, and 4 experienced at least a partial improvement. Of 4 patients evaluated by MRI after RT completion, 3 had complete resolution of CNS disease within the irradiated field. At the time of last follow-up, all patients had died of MF. The median time to death was 7.4 months (range 1.0-21 months) from their diagnosis with CNS involvement and 1.2 months (range 0.4-7.1 months) from the end of RT treatment.

Conclusions

We observed high rates of radiographic response and palliation of neurological symptoms. Nonetheless, all patients succumbed to their disease shortly after treatment, confirming the poor prognosis of this condition. Our findings suggest that RT may play a valuable palliative role for these patients.

Long-term complete remission of early hematological relapse after discontinuation of immunosuppressants following allogeneic transplantation for Sezary syndrome

Sezary syndrome (SS) is a leukemic form of cutaneous T-cell lymphoma and is chemo-resistant. Allogeneic hematopoietic stem cell transplantation is a promising therapy for SS; however, relapse is common. Therapeutic options after relapse have not been established. We managed an SS patient with hematological relapse within one month after transplantation. After discontinuation of immunosuppressants, she achieved complete remission and remained relapse-free. The chimeric analyses of Tcells showed that the full recipient type became complete donor chimera after immunological symptoms. This clinical course suggested that discontinuation of immunosuppressants may result in a graftversus- tumor effect, leading to the eradication of lymphoma cells.

Therapeutic and prognostic significance of PARP-1 in advanced mycosis fungoides and Sezary syndrome

While mycosis fungoides (MF) is typically an indolent malignancy, it may infrequently undertake an aggressive course. We used proteomic analyses to identify a biomarker of the aggressive course of MF. Results of this investigation demonstrated that PARP-1, heat-shock protein family A (Hsp70) member 1 like (HSAP1L), Hsp70 member 1A (HSPA1A), ATP-depending RNA helicase (DDX17) and the α-isoform of lamina-associated polypeptide 2 (TMPO) had higher expression in aggressive disease versus non-aggressive. Moreover, PARP-1 was overexpressed in patients with early stage of MF who developed later an aggressive disease. PARP-1 was evaluated as a new target for therapy, demonstrating the selective dose-dependent cytotoxic effect of PARP inhibitors on Sézary cells in comparison with non-malignant lymphocytes. In conclusion, we believe that PARP-1 may serve not only as a biomarker at initial biopsies for a disease that may become aggressive but also as a new therapeutic target of advanced MF and Sézary syndrome.

Plasma miR-155, miR-203, and miR-205 are Biomarkers for Monitoring of Primary Cutaneous T-Cell Lymphomas

Primary cutaneous T-cell lymphomas (CTCL) affect the skin and tend to transform and spread. CTCL involves primarily the Mycosis fungoides (MF) and more aggressive Sezary syndrome (SS). Oncogenic microRNAs (miRs) are stable epigenetic inhibitors often deregulated in the tumour and detectable as biomarkers in non-cellular fractions of peripheral blood. The tumour-specific expression of miR-155, miR-203, and miR-205 was shown to correctly diagnose CTCL. We herein asked whether these microRNAs can be used as plasma biomarkers for clinical CTCL monitoring. Patients with CTCL (n = 10) and controls with non-malignant conditions (n = 11) repeatedly donated plasma samples every ca. five months. MicroRNAs were detected in the plasma samples by specifically-primed RT-PCR followed by multivariate analyses of the miR expression dynamics. We herein established the plasma miR-classifier for detecting CTCL based on the miR-155 upregulation and miR-203/miR-205 downregulation with 100% specificity and 94% sensitivity. The 3-miR-score in the consecutive samples coincided with the clinical outcome of MF and SS patients such as the therapy response or changes in the clinical stage or tumor size. Quantitation of the selected microRNAs in plasma is a specific and straightforward approach for evaluating CTCL outcome representing, thus, a valuable tool for CTCL diagnostics and therapy response monitoring.

Large Cell Transformation of Oral Mycosis Fungoides

Mycosis fungoides (MF) accounts for approximately 50% of all primary cutaneous lymphomas. MF occurrence in the oral cavity is extremely rare with approximately 45 cases reported to date. We present a case of a 68 year-old man with a raised nodular lesion of the ventral tongue with clinical impression of irritational fibroma. Histopathologic and immunohistochemical (IHC) examination revealed a phenotype consistent with MF with large cell transformation in the context of Sezary syndrome. The histological diagnosis of oral MF requires a high index of suspicion and IHC panel to rule out large cell transformation. To our knowledge, only four cases of large cell transformation of oral MF have been reported in the English literature. The clinical and histopathologic features of a rare case of intra-oral MF with large cell transformation are exemplified in this article.

New Targeted Treatments for Cutaneous T-cell Lymphomas

Cutaneous T-cell lymphomas (CTCLs) represent a group of rare and heterogeneous diseases that are very difficult to treat at advanced stages. The development of monoclonal antibodies is a new hope for the treatment of these diseases. Alemtuzumab (Campath) is a humanized IgG1 kappa monoclonal antibody specific for CD52, an antigen expressed by most T and B lymphocytes. Alemtuzumab may frequently induce long-term remissions in patients with Sezary syndrome but high-dose treatments lead to severe cytopenia, immune depletion, and opportunistic infections. This treatment is less efficient in mycosis fungoides (MF). Brentuximab vedotin is a chimeric anti-CD30 monoclonal antibody conjugated to monomethyl auristatin E, a cytotoxic antitubulin agent. Brentuximab vedotin is a very interesting new treatment for advanced tumor MF, Sezary syndrome, and primary cutaneous CD30+ lymphoproliferative disorders. The main limiting adverse event is neurosensitive peripheral neuropathy. Mogamulizumab is a humanized anti-C-C chemokine receptor Type 4 monoclonal antibody with a defucosylated Fc region leading to increased antibody-dependent cellular cytotoxicity. Mogamulizumab is very efficient on aggressive peripheral T-cell lymphomas, particularly adult T-cell leukemia/lymphoma and CTCLs, especially on the blood component of tumor cells. The main limiting events are related to the concomitant depletion of regulatory T-cells. IPH4102 is a humanized monoclonal antibody that targets the immune receptor KIR3DL2/CD158k. Preclinical results with this antibody offer proofs of concept for the clinical development of IPH4102 to treat patients with advanced CTCL.

An association between newly diagnosed cutaneous T cell lymphoma and prior impetigo: a nested case-control study

Colonization with staphylococcus aureus (SA) is associated with disease activity and progression in patients with cutaneous T-cell lymphoma (CTCL) secondary to T-cell activation by bacterial superantigens. The aim of the current study was to evaluate the possible role of SA as an etiologic factor affecting CTCL initiation. We conducted a nested case-control study in a large population-representative database from the UK. Cases were defined as all patients with an incident diagnosis of mycosis fungoides (MF) or Sezary syndrome (SS) between 1995 and 2013. For every case, four eligible controls matched on age, sex, practice-site, and duration of follow-up were selected. Exposure of interest was clinical diagnosis of impetigo prior to CTCL diagnosis. Conditional logistic regression was used to calculate odds-ratio (ORs) and 95 % confidence-interval (CI) for CTCL risk. The results were further stratified according to age, sex and time interval between impetigo and CTCL diagnosis. The study population included 310 cases with MF or SS and 1223 matched controls. Among cases with CTCL 4.8 % (n = 15) had impetigo prior to cancer diagnosis compared to 2 % (n = 24) of controls. The adjusted OR for CTCL diagnosis among patients with prior impetigo was 2.33 (95 % CI 1.12-4.83). The risk was elevated among individuals with impetigo 1-5 years before cancer diagnosis (OR 3.33, 95 % CI 1.00-11.10). There was no change in risk among patients with impetigo more than 5 years before cancer diagnosis (OR 1.09, 95 % CI 0.35-3.37). Our results suggest a possible association between SA colonization and CTCL initiation that might serve as an important etiological factor for the disease.

Identification of geographic clustering and regions spared by cutaneous T-cell lymphoma in Texas using 2 distinct cancer registries

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) (mycosis fungoides and its leukemic variant, Sezary syndrome) are rare malignancies. Reports of the occurrence of mycosis fungoides in married couples and families raise the possibility of an environmental trigger for this cancer. Although it has been suggested that CTCL arises from inappropriate T-cell stimulation, to the authors' knowledge no preventable trigger has been identified to date.

METHODS

Using region, zip code, age, sex, and ethnicity, the authors analyzed the demographic data of 1047 patients from Texas who were seen in a CTCL clinic at The University of Texas MD Anderson Cancer Center during 2000 through 2012 (the MDACC database) and 1990 patients who were recorded in the population-based Texas Cancer Registry between 1996 and 2010. Subsequently, data from both databases were cross-analyzed and compared.

RESULTS

The current study findings, based on the MDACC database, documented geographic clustering of patients in 3 communities within the Houston metropolitan area, in which CTCL incidence rates were 5 to 20 times higher than the expected population rate. Analysis of the Texas Cancer Registry database defined the CTCL population rate for the state to be 5.8 cases per million individuals per year (95% confidence interval, 5.5-6.0 per million individuals per year), thus confirming the observations from the MDACC database and further highlighting additional areas of geographic clustering and regions spared from CTCL in Texas.

CONCLUSIONS

The current study documented geographic clustering of CTCL cases in Texas and argued for the existence of yet unknown external causes/triggers for this rare malignancy.