Revisions to the staging and classification of mycosis fungoides and Sezary syndrome: a proposal of the International Society for Cutaneous Lymphomas (ISCL) and the cutaneous lymphoma task force of the European Organization of Research and Treatment of Cancer (EORTC)

Poikilodermatous and Ichthyosiform Patches all over the Body and Dark-brown Nodules on the Legs: A Quiz

Abstract is missing (Quiz)

Primary cutaneous lymphoma: recommendations for clinical trial design and staging update from the ISCL, USCLC, and EORTC

The number of patients with primary cutaneous lymphoma (PCL) relative to other non-Hodgkin lymphomas (NHLs) is small and the number of subtypes large. Although clinical trial guidelines have been published for mycosis fungoides/Sézary syndrome, the most common type of PCL, none exist for the other PCLs. In addition, staging of the PCLs has been evolving based on new data on potential prognostic factors, diagnosis, and assessment methods of both skin and extracutaneous disease and a desire to align the latter with the Lugano guidelines for all NHLs. The International Society for Cutaneous Lymphomas (ISCL), the United States Cutaneous LymphomaConsortium (USCLC), and the Cutaneous Lymphoma Task Force of the European Organization for the Research and Treatment of Cancer (EORTC) now propose updated staging and guidelines for the study design, assessment, endpoints, and response criteria in clinical trials for all the PCLs in alignment with that of the Lugano guidelines. These recommendations provide standardized methodology that should facilitate planning and regulatory approval of new treatments for these lymphomas worldwide, encourage cooperative investigator-initiated trials, and help to assess the comparative efficacy of therapeutic agents tested across sites and studies.

Genetic alterations and oxidative stress in T cell lymphomas

T cell lymphomas encompass a diverse group of Non-Hodgkin lymphomas with a wide spectrum of clinical, immunological and pathological manifestations. In the last two decades there has been a progress in our understanding of the cell of origin, genetic abnormalities and their impact on behaviour in T cell lymphomas. Genetic alterations are one of the critical drivers of the pathogenesis of T cell lymphoma. Disease progression has been correlated with multiple genetic abnormalities where malignant clones arise primarily out of the host immune surveillance arsenal. There are many cellular processes involved in disease development, and some of them are T cell signaling, differentiation, epigenetic modifications, and immune regulation. Modulation of these crucial pathways via genetic mutations and chromosomal abnormalities possessing either point or copy number mutations helps tumor cells to develop a niche favourable for their growth via metabolic alterations. Several metabolic pathways especially regulation of redox homeostasis is critical in pathogenesis of lymphoma. Disruption of redox potential and induction of oxidative stress renders malignant cells vulnerable to mitochondrial damage and triggers apoptotic pathways causing cell death. Targeting genetic abnormalities and oxidative stress along with current treatment regime have the potential for improved therapeutics and presents new combination approaches towards selective treatment of T cell lymphomas.

STING expression is an independent prognostic factor in patients with mycosis fungoides

Mycosis fungoides is recognized as an indolent cutaneous malignant T-cell lymphoma. In contrast, there are few therapeutic options for advanced forms of mycosis fungoides. Since immunotherapy is desirable as an alternative therapeutic option, identifying candidate molecules is an important goal for clinicians. Although tumor-derived negative immunomodulatory molecules, such as PD-1/PD-L1, have been identified in various malignancies, the useful positive immunological drivers of mycosis fungoides are largely unknown. We found that the stimulator of interferon (IFN) genes (STING) was highly upregulated in early-stage mycosis fungoides. Immunohistochemical examination revealed different STING staining patterns in patients with mycosis fungoides. Although there were no significant differences in clinical factors’ characteristics, STING expression was associated with the survival of patients with mycosis fungoides. The survival rate was significantly poor in patients with low STING-expressing mycosis fungoides. Univariate and multivariate analyses revealed that low STING expression was associated with an increased hazard ratio. Our results indicate that STING expression independently influences the prognosis of mycosis fungoides.

Efficacy of narrowband UVB phototherapy in early-stage mycosis fungoides in Iranian patients

Narrowband UVB (NB-UVB) has been shown to be effective for the treatment of early mycosis fungoides (MF) in light-skinned patients, but the effect of NB-UVB on patients with darker skin phototypes needs further investigation. The aim of this study was to evaluate the effect of NB-UVB in the treatment of early-stage MF in Iranian patients. In this retrospective study, 24 patients with the diagnosis of early MF (9 stage AI, 15 stage IB) were enrolled. All patients were treated with NB-UVB phototherapy 2-3 times weekly. After achieving complete response, a maintenance treatment was recommended. The response rate, side effects, and recurrence rate in the follow-up period were assessed. The follow-up period was ranged 6 to 24 months. Ten patients (41.7%) had complete remission after a mean number of 42.9 treatment and mean cumulative dose of 58.11 J/cm². Twelve patients (50%) had partial response, and 2 patients (8.3%) had no response. After discontinuation of maintenance treatment, 4 of 10 patients (40%) with complete remission relapsed within a mean of 5 months. Side effects were limited to erythema (12.5%) and hyperpigmentation (4%). NB-UVB is a safe and effective method for the treatment of early MF, but it seems that more treatment sessions and higher doses of NB-UVB are required for darker skin phototypes.

Hyperpigmented mycosis fungoides: a retrospective and comparative analysis with other subtypes of mycosis fungoides

In this study, the clinicopathologic features and survival outcomes of patients with hyperpigmented MF from a single tertiary referral center database were retrospectively evaluated. Hyperpigmented MF accounted for 10.9% (14/128) of all MF cases. The mean age at diagnosis was 46.9 years, and the female-to-male ratio was 1:1.3. Concurrent hypopigmented, ichthyosiform, and poikilodermatous lesions were detected in 21.4%, 14.3%, and 14.3% of the patients, respectively. Histopathologically, most patients (85.7%) showed interface change with pigment incontinence. Double negative (CD4- and CD8-) immunophenotypes were more frequent in patients with hyperpigmented MF (25%) than in those with other MF subtypes (9.8%). Most patients (85.7%) had early-stage disease at diagnosis. The survival outcomes did not differ significantly between hyperpigmented and other MF subtypes. In conclusion, hyperpigmented MF often accompanies other atypical MF variants and is frequently associated with atypical immunophenotypes. The outcomes of hyperpigmented MF are comparable to those of other MF subtypes.

TOX Expression in Mycosis Fungoides and Sezary Syndrome

Mycosis fungoides (MF) and Sezary syndrome (SS) are the two most common type of cutaneous T-cell lymphoma (CTCL). Currently, no markers can be clearly related to prognosis or to differential diagnosis between early stages and inflammatory benign diseases (IBD). The thymocyte selection-associated high mobility group box factor (TOX), has been proposed as a possible marker in differential diagnosis between early CTCL stages and IBD. Recently TOX has been related to prognosis. We aimed to investigate whether TOX may be a diagnostic or prognostic marker. MF and SS biopsies between 2010 and 2020 were retrieved. New tissues slides were stained with an anti-TOX antibody, (Clone NAN448B). On each slide, 5 fields were examined at high magnification (400×), to evaluate the percentage of marker-positivity in a quantitative way. Thirty-six patients (12 females and 24 males) and 48 biopsies were collected. Nine patients had multiple biopsies. TOX expression in MF/SS cases showed an increase from early to advanced phases. TOX was not regarded as a prognostic marker due to the absence of significant changes by comparing early MF cases with reactive conditions. TOX statistical significance increased in patients alive with disease and in those dead of disease (p = 0.013 and = 0.0005, respectively) as compared with patients in complete remission. Our results show that TOX should be regarded more as a prognostic than a diagnostic marker.

Combined High-Throughput Approaches Reveal the Signals Driven by Skin and Blood Environments and Define the Tumor Heterogeneity in Sézary Syndrome

Simple Summary

Sézary syndrome (SS) is a leukemic and incurable variant of cutaneous T-cell lymphoma characterized by the accumulation of neoplastic CD4+ lymphocytes in the blood, lymph nodes, and skin. With the exception of allogenic transplantation, no curative chance is available to treat SS, and it is a priority to find new therapies that target SS cells within all disease compartments. This review aims to summarize the more recent analyses conducted on skin- and blood-derived SS cells concurrently obtained from the same SS patients. The results highlighted that skin-SS cells were more active/proliferating with respect to matched blood SS cells that instead appeared quiescent. These data shed the light on the possibility to treat blood and skin SS cells with different compounds, respectively. Moreover, this review recaps the more recent findings on the heterogeneity of circulating SS cells that presented a series of novel markers that could improve diagnosis, prognosis and therapy of this lymphoma.

Abstract

Sézary syndrome (SS) is an aggressive variant of cutaneous t-cell lymphoma characterized by the accumulation of neoplastic CD4+ lymphocytes—the SS cells—mainly in blood, lymph nodes, and skin. The tumor spread pattern of SS makes this lymphoma a unique model of disease that allows a concurrent blood and skin sampling for analysis. This review summarizes the recent studies highlighting the transcriptional programs triggered by the crosstalk between SS cells and blood–skin microenvironments. Emerging data proved that skin-derived SS cells show consistently higher activation/proliferation rates, mainly driven by T-cell receptor signaling with respect to matched blood SS cells that instead appear quiescent. Biochemical analyses also demonstrated an hyperactivation of PI3K/AKT/mTOR, a targetable pathway by multiple inhibitors currently in clinical trials, in skin SS cells compared with a paired blood counterpart. These results indicated that active and quiescent SS cells coexist in this lymphoma, and that they could be respectively treated with different therapeutics. Finally, this review underlines the more recent discoveries into the heterogeneity of circulating SS cells, highlighting a series of novel markers that could improve the diagnosis and that represent novel therapeutic targets (GPR15, PTPN13, KLRB1, and ITGB1) as well as new genetic markers (PD-1 and CD39) able to stratify SS patients for disease aggressiveness.

Chlormethine Gel is Efficient and Safe in Mycosis Fungoides Skin Lesions

Chlormethine is a bifunctional cytotoxic alkylating agent that binds to DNA, resulting in cell death (apoptosis). Chlormethine (also known as mechlorethamine) gel (CL gel) was approved in the European Union in 2017 and was first used in 2019. The aim of the study is to examine evidence regarding the efficacy and safety of chlormethine gel in everyday clinical experience from a cutaneous lymphoma centre. Twenty-three patients with stage IA-IIB mycosis fungoides received chlormethine gel between September 2020 and May 2021. All patients started by applying the gel daily and were monitored every month. At 1, 3, 6 and 9 months, 0%, 43.47%, 56.52% and 65.22% of patients, respectively, achieved an overall response. Five out of 23 patients (21.73%) achieved near complete response at a mean time of 6 months. Chlormethine gel was given as monotherapy in 12 patients (52.17%), and in addition to systemic treatments (methotrexate and peginterferon alpha-2a) in 11 patients (47.82%). Adverse events (AE) were recorded in 43.47% of patients, but only 3 discontinued treatment, due to dermatitis. Scale down of the treatment to application 3-times per week led to better patient compliance. This study shows that chlormethine gel is effective and safe in patients with mycosis fungoides with different types of skin lesions.

Retrospective Analysis of 118 Patients With Cutaneous T-Cell Lymphomas: A Single-Center Experience

Cutaneous T-cell lymphomas (CTCL) represent rare non-Hodgkin lymphomas (NHL) with an incidence less than 1 per 100,000 inhabitants. The most common type of CTCL is mycosis fungoides (MF), which represents approximately 60% of all CTCL, followed by Sézary syndrome (SS), approximately 5%. We retrospectively analyzed the outcome of 118 patients with MF (n=96) and SS (n=22) treated between the years 1998 and 2021 at the Charles University General Hospital in Prague, Czech Republic. The ratio between men and women was 1.2:1 (62 men, and 56 women). The median age at diagnosis was 62 years (23 to 92 years). From the MF cohort 48 patients (50% out of MF cohort) presented with advanced stage disease. Ninety patients (77%) received a systemic treatment at any time from the diagnosis; the median number of therapy lines was two. At the time of database lock, the overall survival (OS) of 96 patients with MF reached 17.7 years with the median follow-up 4.0 years. With the median follow-up 2.6 years, the median OS of 22 patients with SS was 3.5 years. The most common type of systemic therapy for MF included low-dose methotrexate (61%), interferon-alpha (58%), bexarotene (28%), and chlorambucil (25%). The most common type of therapy for SS included bexarotene (64%), extracorporeal photopheresis (50%), and interferon-alpha (45%). Only the minority of patients received innovative targeted agents including brentuximab vedotin, mogamulizumab, or pembrolizumab. Besides the retrospective analysis of the CTCL cohort, current standards and future perspectives of selected innovative agents are summarized and discussed. The analyzed cohort represents the largest cohort of CTCL patients in the Czech Republic. Overall, the survival parameters of our CTCL cohort are comparable to those previously published by other groups. In conclusion, our analysis of 118 real world cohort of consecutive CTCL patients treated at the single center confirmed the efficacy of immune response modifiers and underlines the urgent need for ample implementation of innovative agents and their combinations into earlier lines of therapy.

Efficacy of brentuximab vedotin in patients with CD30-positive lymphoproliferative skin diseases: results of the first prospective study in the Russian Federation

Background. Primary cutaneous lymphomas are the second most common group of extranodal lymphomas. Unlike nodal lymphomas, where B-cell proliferations dominate, primary cutaneous T-cell lymphomas account for 6575% of all cutaneous lymphomas. Among T-cell lymphomas of the skin, about 50% of cases are mycosis fungoides (MF), the second place in frequency of occurrence is occupied by CD30-positive lymphoproliferative skin diseases (CD30 LPD), about 10% are rare nosological forms, such as primary cutaneous peripheral T-cell lymphoma, unspecified, Sezari syndrome (SS), etc. During the initiating treatment of patients with MF and Szary syndrome (SS), carried out on the territory of the Russian Federation, for about 30% of patients are resistant to various therapeutic effects, especially in the later stages. The problem of the treatment of CD30+ LPD is extracutaneous dissemination in case of primary cutaneous anaplastic large cell lymphoma (pcALCL), steadily relapsing course of lymphomatoid papulosis (LyP) without symptom-free intervals. These characteristics of the therapy of cutaneous lymphomas demand for the need to search for new treatment options. Brentuximab vedotin, according to the results of the international randomized ALCANZA trial, has shown high efficiency in the treatment of cutaneous T-cell lymphoproliferative diseases. Aim. To evaluate the efficacy of brentuximab vedotin application in patients with cutaneous T-cell lymphomas in adverse risk group received at least one line of systemic therapy. Materials and methods. The study included 21 patients: 16 men and 5 women. The diagnosis of MF was verified in 8 patients, SS in 5 patients, cutaneous CD30+ LPD in 6 patients (5 patients pcALCL, 1 patient LyP) and a primary cutaneous peripheral T-cell lymphoma, unspecified in 2 patients. The diagnosis of cutaneous T-cell lymphoma was verified on the basis of the anamnesis of the disease, on the character of cutaneous lesions, on histological, immunohistochemical and in some cases on molecular genetic testing of the skin biopsy (the assessment of T-cell receptor gene rearrangement). Results. The late stages of the disease were diagnosed in 12 of 13 patients with MF/SS. Extracutaneous lesions were diagnosed in 57% of cases. The median of prior lines therapy was 3 (18 variants of treatment). The overall response to the treatment was achieved in 91% of cases (in 19 of 21 patients): the complete remission was obtained in 53% of cases, very good partial remission in 31% of cases and partial remission in 16% of cases. The progression of the disease was determined in 2 patients (after the first and fourth cycles). Some patients with partial remission as a result of therapy using brentuximab vedotin had the additional therapy (radiation therapy, interferon , the cycles of systemic therapy) and these acts gave an option of achieving deeper antitumor response. The early relapse was diagnosed in 2 of 19 patients who had responded to the treatment. The treatment tolerability was acceptable, and the toxicity did not exceed the already known one described in earlier studies. Thus, the stable overall antitumor response had been persisting in 89% of patients (the median of the observation was 10 months). Conclusion. The use of targeted therapy with brentuximab vedotin gave an option of achieving high treatment results in group of patients with advanced stages of the disease and inefficiency of several lines of therapy.

"Alterations in the Skin Microbiota Are Associated With Symptom Severity in Mycosis Fungoides"

Cutaneous T cell lymphoma (CTCL), a non-Hodgkin lymphoma, is thought to arise from mature tissue-resident memory T cells. The most common subtypes include Mycosis Fungoides and Sezary Syndrome. The role of skin microbiota remains unclear in the symptom manifestation of MF. Among 39 patients with MF, we analyzed bacteria colonizing MF lesions and non-lesional skin in the contralateral side and characterized regional changes in the skin microbiota related to MF involvement using the difference in relative abundance of each genus between lesional and contralateral non-lesional skin. We investigated the relationship between these skin microbiota alterations and symptom severity. No statistically significant difference was found in bacterial diversity and richness between lesional and non-lesional skin. Different skin microbiota signatures were associated with different symptoms. More pronounced erythema in the lesions was associated with an increase in Staphylococcus. Pain and thick skin in the lesions were associated with a decrease in Propionibacterium. The results of this pilot study suggest that the skin microbiota plays an important role in changing skin phenotypes among patients with MF. Larger skin microbiota studies are needed to confirm these findings and support the use of antibiotic treatment to mitigate CTCL symptoms.

Changes in total skin electron beam therapy modalities for mycosis fungoides: A single-centre study

BACKGROUND

Mycosis fungoides (MF) is a highly radiosensitive disease. Total skin electron beam therapy (TSEBT) is an effective option that may allow prolonged response for several months. Recently, a low-dose regimen (12 Gy) has been reported more frequently, with less complete response than for standard doses (36 Gy) but better safety. Our aim was to compare patients treated with 12-Gy and 36-40-Gy TSEBT regimens at our centre for efficacy and safety.

METHODS

This retrospective, monocentric study in Bordeaux University Hospital included all MF patients treated with 12-Gy or 36-40-Gy TSEBT between 2011 and 2020.

RESULTS

Patients presented with MF at the following stages: 15 T2, including 9 folliculotropic MF; 2 T3, including 1 folliculotropic; 8 T4, including 2 Sézary syndromes. The mean follow-up time after TSEBT was 43.5 months [range: 2-128] for the 36-40-Gy group and 25.2 months [range: 4-45] for the 12-Gy group. The 3-month overall response rate (ORR) was similar for both groups (84.6% for 36-40 Gy and 91.7% for 12 Gy), but there was a tendency to more complete response in the 36-40-Gy group (30.8% vs 8.3%, P=0.35). Progression-free survival (PFS) tended to be better in the 36-40-Gy group than in the low-dose group (15.7 months vs 5.3 months; P=0.28). Patients treated with low-dose TSEBT had a lower incidence of radiation dermatitis (16.7% vs 38.4%, P=0.42).

CONCLUSION

We confirm that TSEBT is an effective option, including at lower doses. Differences between low- and standard-dose regimens were not significant in our series. Although a low-dose regimen seemed to result in lower complete response and long-term efficacy rates in comparison with a standard dose, treatment at lower doses presents the advantage of repeatability, with fewer and weaker side effects, in the event of disease recurrence. Second-line treatments were mostly skin-directed in this group.

Care structure of patients with mycosis fungoides and Sézary syndrome in Germany - Care research based on SHI claims data

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) are rare forms of non-Hodgkin's lymphoma of T-cell origin that occur mainly in the skin. The most common form is mycosis fungoides (MF), but Sézary syndrome (SS), a more aggressive form of CTCL, is another relevant subgroup. Due to the rare nature of the disease, population-based studies of the epidemiology and disease burden and insights into care delivery are limited.

PATIENTS AND METHODS

Based on an anonymized, age and sex-adjusted routine dataset comprising approximately five million people with statutory health insurance, a retrospective, longitudinal healthcare research study was conducted over a six-year period (2012-2017).

RESULTS

In 55 % of patients with MF and SS, the initial diagnosis was documented in an outpatient setting; in 59 % of cases by a dermatologist. Immunophenotyping by flow cytometry is considered an important investigative tool for the detection and follow-up surveillance of blood involvement of cutaneous lymphomas, as the disease stage is the most important prognostic factor in MF and SS; this was performed in only 10 % of patients. The first-line treatment was topical (76 %), in particular with corticosteroids (66 %).

CONCLUSIONS

The findings from this healthcare research point to the need for increased guideline-based care.

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.

The PROCLIPI international registry, an important tool to evaluate the prognosis of cutaneous T cell lymphomas

PROCLIPI is the PROgnostic Cutaneous Lymphoma International Prognostic Index Study with the main aim to produce a prognostic index in mycosis fungoides (MF) and Sezary syndrome (SS). The study prospectively collects clinical, haematological, pathological, imaging, treatment with responses, quality of life and survival data using careful predefined datasets. Patients are subject to a central review to confirm diagnosis. PROCLIPI opened in 2015 and recruitment has been strong with to date 1916 patients recruited from 52 Centres from 19 countries across 6 continents.

Subtlety of Granulomatous Mycosis Fungoides: A Retrospective Case Series Study and Proposal of Helpful Multimodal Diagnostic Approach With Literature Review

ABSTRACT

Granulomatous mycosis fungoides (GMF) harbors a worse prognosis compared with classic MF and remains a significant diagnostic dilemma. We analyzed clinicopathologic, immunophenotypic, and molecular characteristics of GMF to develop a diagnostic algorithm. Our methodology involved a retrospective case series study of patients with GMF from our database between 2014 and 2020. A total of 8 patients with 9 biopsies of GMF were identified. Skin manifestations had variable clinical phenotype. Histologically, all cases demonstrated atypical CD4+ T-cell infiltrate with scant in 50% (n = 4), focal 37.5% (n = 3), and absent 25% (n = 2) epidermotropism. Granuloma formation was seen in 77.8% biopsies (n = 7) with sarcoid-type granulomas in 57.1% (n = 4) and granuloma annulare-like type in 42.9% (n = 3). In 66.7% of biopsies (n = 6), the CD4:CD8 ratio was >4:1 and 66.6% (n = 6) of biopsies showed ≥50% loss of CD7 expression. T-cell receptor gene rearrangement studies performed on biopsy sections were positive in all biopsies (n = 6), whereas peripheral blood T-cell receptor gene rearrangement studies did not identify clonality. In conclusion, GMF has subtle or absent epidermotropism and variable granulomatous reaction; thus, the diagnosis requires a multimodal approach, and our proposed algorithm provides a framework to approach this diagnostic challenge.

PD-1 and PD-L1 expression in mycosis fungoides and Sézary Syndrome

BACKGROUND

The mechanisms involved in mycosis fungoides and Sezary Syndrome progression are largely unknown. Over the last decade the interest in immune system contrast of neoplasm has grown owing to the introduction of immunotherapy. PD-1 and its ligand (PD-L1) are the target of several immunotherapy treatment. In the literature reports on the expression of PD-1 and PD-L1 have provided contrasting results.

METHODS

In our analysis we investigated PD-1 expression in neoplastic cells and in tumour infiltrating lymphocytes (TILs) as well as PD-L1 expression in tumour cells and in tumour associated macrophages (TAMs). PD-L1 and PD-1 positive cells were counted in 5 high-power fields (HPF) and scored as the average number of positive neoplastic cells/TILs/TAMs per HPF.

RESULTS

From databases of two institutions (Bologna and Florence) thirty-five patients corresponding to 43 biopsies were retrieved. In seven instances sequential biopsies were present. No statistically significant expression was observed comparing early to advanced stages by analysing PD-1 by tumour cells and TILs and of PD-L1 by tumour cells and TAMs.

CONCLUSIONS

Our results corroborate that PD-1 and PD-L1 expression is not stage-dependent in mycosis fungoides and Sezary syndrome. However, PD-1 and PD-L1 expression in affected patients provides a rationale to schedule anti PD-1/PD-L1 drugs.

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.

CD30+ Lymphoproliferative Disorders as Potential Candidates for CD30-Targeted Therapies

CONTEXT.—

In the early 1980s, a monoclonal antibody termed Ki-1 was developed against a cell line derived from a patient with Hodgkin lymphoma. This antibody detected a limited number of benign activated lymphocytes in lymphoid tissue, whereas in Hodgkin lymphoma it appeared to be nearly specific for Reed-Sternberg cells and their mononuclear variants. Subsequent studies showed that Ki-1 expression defined a new type of lymphoma that was later designated anaplastic large cell lymphoma with or without anaplastic large cell kinase expression/translocation. In the past 30 years, numerous new lymphoma entities have been defined, many of which are variably positive for CD30. Many virally transformed lymphoproliferative disorders are also frequently positive for CD30.

OBJECTIVE.—

To illustrate the broad spectrum of CD30+ hematologic malignancies and to provide an update of CD30-targeted therapies.

DATA SOURCES.—

Personal experiences and published works in PubMed.

CONCLUSIONS.—

Because of its low expression in normal tissue, CD30 was studied as a therapeutic target for many years. However, the first functional humanized antibody against CD30 was developed only about 10 years ago. Brentuximab vedotin is a humanized anti-CD30 antibody linked to a cytotoxin, and was approved by the US Food and Drug Administration in 2012 for treating refractory Hodgkin lymphoma and anaplastic large cell lymphoma. Since then, the list of Food and Drug Administration-approved CD30-targeted hematologic malignancies has grown. Recently, the therapies using tumor antigen-specific chimeric antigen receptor T cells targeting CD30 have incited a great deal of enthusiasm and are studied in clinical trials.

Impact of Mogamulizumab in Real-Life Advanced Cutaneous T-Cell Lymphomas: A Multicentric Retrospective Cohort Study

Simple Summary

Mogamulizumab is a recent monoclonal antibody prescribed in the second line to treat advanced mycosis fungoides and Sézary syndromes. We collected data from all patients who used mogamulizumab in six French university hospitals until 1 September 2021. Our primary objective was to determine the median progression free survival (PFS). Secondary objectives were to consider tolerance regarding side effect occurrence and severity. Twenty-one patients were included, with a median time of follow-up of 11.6 months, and progression-free survival was estimated at 22 months. Twenty patients presented adverse events, of which 10 were severe. The median time between the introduction of mogamulizumab and the first adverse event was 21 days. Our study suggests that mogamulizumab is a significant treatment option to extend PFS in patients with advanced refractory cutaneous T-cell lymphomas (CTCL). The long-term safety of mogamulizumab was determined to be acceptable since we reported few grade III–IV adverse events (AEs) compared to other systemic treatments.

Abstract

Background: Advanced mycosis fungoides (MF) and Sézary syndrome (SS) are rare, aggressive cutaneous T-cell lymphomas that may be difficult to treat. Mogamulizumab is a recent monoclonal antibody targeting the CCR4 receptor expressed on the surface of Sézary cells. It can be prescribed in MF/SS stages III to IV in the second line after systemic therapy or in stages IB-II after two unsuccessful systemic therapies. We lack data on long-term efficiency and potential side effects in real-life conditions. Our study aims to determine efficacy considering the median PFS of advanced CTCL with mogamulizumab. Secondary objectives were to consider tolerance and estimate delay until side effects appeared. Methods: Data on patients with advanced cutaneous T-cell lymphomas were collected since French Authorization, in six French university hospitals. Patients were followed until they stopped mogamulizumab because of relapse or toxicity. For those still treated by mogamulizumab, the end point was 1 September 2021. We excluded 3 patients as they had already been included in the MAVORIC study and data was not available. Results: The median time of follow-up was 11.6 months. Of the 21 patients included, we reported four full-response patients, eight in partial response, one in stability, three in progression, and five were deceased. One patient had visceral progression, and seven had new lymphadenopathy. Progression-free survival was estimated at 22 months. Twenty patients presented adverse events, of which 10 were severe, i.e., grade III-IV. The median time between the introduction of mogamulizumab and the first adverse event was 21 days. Conclusions: Our study suggests that mogamulizumab can give patients with advanced refractory CTCL a consequent PFS, estimated at 22 months. The long-term safety of mogamulizumab was determined to be acceptable since we reported few grade III–IV AEs, comparable with other studies. No other study using real-life data has been performed to investigate the AEs of mogamulizumab.

Survival and Prognostic Factors in Patients with Aggressive Cutaneous T-cell Lymphomas

Aggressive primary cutaneous T-cell lymphomas include advanced-stage mycosis fungoides (stage ≥ IIB mycosis fungoides), Sézary syndrome, gamma/delta cutaneous lymphoma, nasal type lymphoma, aggressive epidermotropic CD8+ T-cell lymphoma and some cutaneous lymphomas not otherwise specified. To evaluate their long-term prognosis, we conducted a retrospective cohort study of 85 patients diagnosed between 2005 and 2020 with advanced-stage mycosis fungoides (n = 48), Sézary syndrome (n = 28) or aggressive non-mycosis fungoides/Sézary syndrome subtypes (n = 9). The median survival times in these 3 groups were 118.7, 45.7 and 11.2 months, respectively, and the 5-year survival rates were 55.3%, 27.8% and 33.3%, respectively. Multivariate analyses in patients with mycosis fungoides/Sézary syndrome identified age ≥ 70 years, Eastern Cooperative Oncology Group Performance Status ≥ 2, and the high-risk group according to the Cutaneous Lymphoma International Consortium prognostic model, as adverse prognostic factors. Seven patients in this mycosis fungoides/Sézary syndrome group were in complete long-term remission after treatment with bexarotene, including 4 patients living without any treatment for 16–101 months.

Epidemiological Characteristics and the Development of Prognostic Nomograms of Patients With HIV-Associated Cutaneous T-Cell Lymphoma

Background

The incidence of human immunodeficiency virus (HIV) associated cutaneous T-Cell lymphoma (HIV-associated CTCL) is very low, and there is a lack of relevant epidemiological and clinical prognostic studies. Therefore, we aimed to study the epidemiological characteristics of HIV-associated CTCL and to construct and validate a nomogram predicting patient survival.

Methods

Demographic, clinical characteristics, and incidence data from the Surveillance, Epidemiology and End Results (SEER) database were screened for patients with HIV-associated CTCL. Independent prognostic factors in patients with HIV-associated CTCL were analyzed to establish nomograms of overall survival (OS) and disease-specific survival (DSS) rates of patients. The performance of the prediction model was validated by the consistency index (C-index), the area under the receiver operating characteristic curve (AUC), and calibration plots.

Results

A total of 883 eligible patients were screened for inclusion in this study and randomized to the training cohort (70%, n = 619) and the validation cohort (30%, n = 264). The age-adjusted average incidence rate per 100,000 persons per year for HIV-associated CTCL was 0.071 for the period 2004-2017, with an increasing incidence rate. The median age of the included patients was 59 years, of which male Caucasian held a majority. 99.5% of the patients had a tumor tissue subtype of mycosis fungoides, while the other tumor subtypes were sézary syndrome. The median OS for patients with HIV-associated CTCL was 162 months, and the OS rates at 1, 3, 5, and 10 years were 0.964, 0.904, 0.835, and 0.766, respectively. Univariate and multivariate COX regression analysis were performed, and prognostic indicators such as "Age", "Radiation", "Chemotherapy", "Summary stage", "Sequence number" were ultimately incorporated and used to establish nomograms of OS and DSS rates at 1, 3, 5 and 10 years for the training cohort. The C-index, AUC, and calibration plot confirmed that our prediction model had good accuracy.

Conclusion

While HIV-associated CTCL is very rare, its incidence has been on the rise in the last decade or so. We described the epidemiological characteristics and prognostic factors in patients with HIV-associated CTCL.

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.

MicroRNA Regulation of T-Cell Exhaustion in Cutaneous T Cell Lymphoma

Cutaneous T cell lymphoma (CTCL) is characterized by a background of chronic inflammation, where malignant CTCL cells escape immune surveillance. To study how microRNAs (miRs) regulate T-cell exhaustion, we performed miR sequencing analysis, qRT-PCR, and in situ hybridization on 45 primary CTCL samples, three healthy skin samples, and CTCL cell lines, identifying miR-155-5p, miR-130b-3p, and miR-21-3p. Moreover, miR-155-5p, miR-130b-3p, and miR-21-3p positively correlated with immune checkpoint gene expression in lesional skin samples and were enriched in the IL-6/Jak/signal transducer and activator of transcription signaling pathway by gene set enrichment analysis. Further gene sequencing analysis showed decreased mRNA expression of the major negative regulators of Jak/signal transducer and activator of transcription signaling: SOCS, PIAS, and PTPN. Transfection of MyLa and HuT78 cells with anti-miR-155-5p, anti‒miR-21-3p, and anti‒miR-130b revealed a considerable increase in SOCS proteins along with a significant decrease in the levels of activated signal transducer and activator of transcription 3 and immune checkpoint surface protein expression as well as decreased cell proliferation. Downregulation of miR-155, miR-130, and miR-21 in CTCL cell lines decreased CTCL cell growth and facilitated CD8⁺ T-cell-mediated cytotoxic activity, with concordant production of IFN-γ and CD107a expression. Our results describe the mechanisms of miR-induced T-cell exhaustion, which provide a foundation for developing synthetic anti-miRs to therapeutically target the tumor microenvironment in CTCL.

Expression of Immune Checkpoint Molecules PD1, PD-L1 and ICOS in Mycosis Fungoides and Sézary Syndrome: Association with Disease Stage and Clinical Outcome

Background

The relationship between immune checkpoint status and disease outcome is a major focus of research in cutaneous T‐cell lymphoma (CTCL), a disfiguring neoplastic dermatological disorder. Mycosis fungoides (MF) and Sézary syndrome (SS) are the two most common types of CTCL.

Objectives

The aim was to evaluate the immune checkpoint markers programmed death protein 1 (PD1), inducible T‐cell co‐stimulator (ICOS) and programmed death‐ligand 1 (PD‐L1) in skin biopsies from patients with CTCL relative to disease stage and overall survival.

Methods

This consecutive case series enrolled 47 patients: 57% had stage IA–IIA disease and 43% had stage IIB–IVA2 disease (including seven with SS).

Results

PD1, PD‐L1 and ICOS expression was seen in all biopsies. Notably, PD‐L1 was predominantly expressed on histiocytes/macrophages, but focal expression on CTCL cells was seen. High expression of either ICOS or PD‐L1 was associated with advanced‐stage disease (P = 0·007 for both) and with the appearance of large‐cell transformation (LCT), a histopathological feature associated with a poor prognosis (ICOS: P = 0·02; PD‐L1: P = 0·002). PD1 expression was not significantly associated with disease stage (P = 0·12) or LCT (P = 0·49), but expression was high in SS biopsies. A high combined checkpoint marker score (PD1, PD‐L1 and ICOS) was associated with advanced‐stage disease (P = 0·001), LCT (P = 0·021) and lower overall survival (P = 0·014).

Conclusions

These findings demonstrate the existence of a complex immunoregulatory microenvironment in CTCL and support the development of immunotherapies targeting ICOS and PD‐L1 in advanced disease.

Flow cytometry for the assessment of blood tumour burden in cutaneous T-cell lymphoma: towards a standardised approach

Mycosis fungoides (MF) and Sézary syndrome (SS) are the best-studied subtypes of cutaneous T-cell lymphoma, a rare non-Hodgkin lymphoma that primarily presents in the skin but can also involve blood, lymph nodes, and viscera. The role of blood involvement in the assessment and staging of MF and SS has evolved in recent years from being classed as simply 'present' or 'absent', with no impact on staging, to full analysis of abnormal peripheral-blood T cells using flow cytometry (FC) to detect and quantify aberrant T-cell phenotypes and polymerase chain reaction (PCR) to characterise T-cell receptor gene rearrangements. These sensitive peripheral-blood assessments are replacing manual Sézary cell counts and have become an important part of clinical work-up in MF and SS, providing the potential for more accurate prognostication and appropriate management. However, although international recommendations now include guidelines for FC analysis of peripheral-blood markers for staging purposes, many clinics only perform these analyses in advanced-stage patients, if at all, and there is still a need for standardised use of validated markers. Standardisation of a single effective multiparameter FC panel would allow for accurate identification and quantification of blood tumour burden for diagnosis, staging, assessment of therapeutic response, and monitoring of disease progression at all stages of disease. Once defined, validation of an MF/SS biomarker FC panel will enable uptake into clinical settings along with associated standardisation of protocols and reagents. This review discusses the evolution of the role of FC in evaluating blood involvement in MF and SS, considers recently published international guidelines, and identifies evidence gaps for future research that will allow for standardisation of FC in MF and SS.

Understanding Cell Lines, Patient-Derived Xenograft and Genetically Engineered Mouse Models Used to Study Cutaneous T-Cell Lymphoma

Cutaneous T cell lymphoma (CTCL) is a spectrum of lymphoproliferative disorders caused by the infiltration of malignant T cells into the skin. The most common variants of CTCL include mycosis fungoides (MF), Sézary syndrome (SS) and CD30⁺ Lymphoproliferative disorders (CD30⁺ LPDs). CD30⁺ LPDs include primary cutaneous anaplastic large cell lymphoma (pcALCL), lymphomatoid papulosis (LyP) and borderline CD30⁺ LPD. The frequency of MF, SS and CD30⁺ LPDs is ~40–50%, <5% and ~10–25%, respectively. Despite recent advances, CTCL remains challenging to diagnose. The mechanism of CTCL carcinogenesis still remains to be fully elucidated. Hence, experiments in patient-derived cell lines and xenografts/genetically engineered mouse models (GEMMs) are critical to advance our understanding of disease pathogenesis. To enable this, understanding the intricacies and limitations of each individual model system is highly important. Presently, 11 immortalized patient-derived cell lines and different xenograft/GEMMs are being used to study the pathogenesis of CTCL and evaluate the therapeutic efficacy of various treatment modalities prior to clinical trials. Gene expression studies, and the karyotyping analyses of cell lines demonstrated that the molecular profile of SeAx, Sez4, SZ4, H9 and Hut78 is consistent with SS origin; MyLa and HH resemble the molecular profile of advanced MF, while Mac2A and PB2B represent CD30⁺ LPDs. Molecular analysis of the other two frequently used Human T-Cell Lymphotropic Virus-1 (HTLV-1)⁺ cell lines, MJ and Hut102, were found to have characteristics of Adult T-cell Leukemia/Lymphoma (ATLL). Studies in mouse models demonstrated that xenograft tumors could be grown using MyLa, HH, H9, Hut78, PB2B and SZ4 cells in NSG (NOD Scid gamma mouse) mice, while several additional experimental GEMMs were established to study the pathogenesis, effect of drugs and inflammatory cytokines in CTCL. The current review summarizes cell lines and xenograft/GEMMs used to study and understand the etiology and heterogeneity of CTCL.

PEG10 amplification at 7q21.3 potentiates large-cell transformation in cutaneous T-cell lymphoma

Mycosis fungoides (MF), the most common form of cutaneous T-cell lymphoma, undergo large-cell transformation (LCT) in the late stage, manifesting aggressive behavior, resistance to treatments, and poor prognosis, but the mechanisms involved remain unclear. To identify the molecular driver of LCT, we collected tumor samples from 133 MF patients and performed whole-transcriptome sequencing on 49 advanced-stage MF patients, followed by integrated copy number inference and genomic hybridization. Tumors with LCT showed unique transcriptional programs and enriched expressions of genes at chr7q. Paternally expressed gene 10 (PEG10), an imprinted gene at 7q21.3, was ectopically expressed in malignant T cells from LCT, driven by 7q21.3 amplification. Mechanistically, aberrant PEG10 expression increased cell size, promoted cell proliferation, and conferred treatment resistance by a PEG10/KLF2/NF-κB axis in in vitro and in vivo models. Pharmacologically targeting PEG10 reversed the phenotypes of proliferation and treatment resistance in LCT. Our findings reveal new molecular mechanisms underlying LCT and suggest that PEG10 inhibition may serve as a promising therapeutic approach in late-stage aggressive T-cell lymphoma.

Sézary Syndrome: Different Erythroderma Morphological Features with Proposal for a Clinical Score System

Sézary syndrome is a rare subtype of cutaneous T-cell lymphoma characterized by erythroderma, peripheral lymphadenopathies, and circulating atypical cerebriform T-cells. To date, no definite staging system has been developed for these patients. In this retrospective analysis of the archive of the Dermatological Clinic of the University of Turin, Italy, erythrodermic SS patients were classified according to clinical records and photographs into three main presentations: erythematous, infiltrated, or melanodermic. The pattern of erythroderma was found to be associated with disease outcome, as better survivals were recorded in patients with erythematous and infiltrative erythroderma. Patients in the melanodermic group, though less represented in our investigation, seemed to show a worse trend in survival. According to this preliminary evidence, a new prognostic classification, with a revised score specific for Sézary syndrome patients, can be proposed to usefully integrate the current staging system. The correlation displayed in our research will be hopefully confirmed by prospective studies with larger cohorts, with the aim of identifying significant prognostic features in this subset of cutaneous T-cell lymphoma patients.

Transcriptional Heterogeneity and the Microbiome of Cutaneous T-Cell Lymphoma

Cutaneous T-Cell Lymphomas (CTCL) presents with substantial clinical variability and transcriptional heterogeneity. In the recent years, several studies paved the way to elucidate aetiology and pathogenesis of CTCL using sequencing methods. Several T-cell subtypes were suggested as the source of disease thereby explaining clinical and transcriptional heterogeneity of CTCL entities. Several differentially expressed pathways could explain disease progression. However, exogenous triggers in the skin microenvironment also seem to affect CTCL status. Especially Staphylococcus aureus was shown to contribute to disease progression. Only little is known about the complex microbiome patterns involved in CTCL and how microbial shifts might impact this malignancy. Nevertheless, first hints indicate that the microbiome might at least in part explain transcriptional heterogeneity and that microbial approaches could serve in diagnosis and prognosis. Shaping the microbiome could be a treatment option to maintain stable disease. Here, we review current knowledge of transcriptional heterogeneity of and microbial influences on CTCL. We discuss potential benefits of microbial applications and microbial directed therapies to aid patients with CTCL burden.

Immunohistochemical Expression Patterns of CD45RO, p105/p50, JAK3, TOX, and IL-17 in Early-Stage Mycosis Fungoides

The morphologic changes in early-stage mycosis fungoides (MF) might overlap with benign inflammatory dermatitis (BID). Previous studies have described altered expression patterns of several proteins in MF, but their diagnostic significance is uncertain. This study aims at examining the frequency of expression of CD45RO, NFkB-p105/p50, JAK3, TOX, and IL-17 proteins by immunohistochemistry. The cohorts included 21 patients of early-stage MF and 19 with benign BID as a control group. CD45RO was positive in all patients of MF and BID. NFkB-p105/p50 showed normal cytoplasmic staining, indicating an inactive status in all patients of both groups. JAK3 was positive in 3 (14%) MF and in 17 (89%) BID patients (p = 0.003). TOX was expressed in 19 (90%) and 13 (68%) patients of MF and BID, respectively (p = 0.120). IL-17 was detected in 13 (62%) MF and in 7 (37%) BID patients (p = 0.056). Co-expression of TOX and IL-17 was seen in 11 (52%) MF patients but in only 3 (16%) BID patients, which was statistically significant (p = 0.021). We conclude that a double expression of TOX and IL-17 may support the diagnosis of MF in the right clinicopathologic setting, while none of the immunohistochemical stains alone provided a significant discrimination between MF and BID.

The Role of Tumor Microenvironment in the Pathogenesis of Sézary Syndrome

Sézary syndrome is an aggressive leukemic variant of cutaneous T-cell lymphomas, characterized by erythroderma, lymphadenopathy, and peripheral blood involvement by CD4+ malignant T-cells. The pathogenesis of Sézary syndrome is not fully understood. However, the course of the disease is strongly influenced by the tumor microenvironment, which is altered by a combination of cytokines, chemokines, and growth factors. The crosstalk between malignant and reactive cells affects the immunologic response against tumor cells causing immune dysregulation. This review focuses on the interaction of malignant Sézary cells and the tumor microenvironment.

Recent advances on cutaneous lymphoma epidemiology

BACKGROUND

Primary cutaneous lymphomas are a group of T- (CTCL) and B-cell (CBCL) malignancies. These diseases have different clinical presentations and prognosis. Our knowledge on their epidemiology is limited. Aim of this review was to summarise recent findings on the incidence of CTCL and CBCL, how they change over time, and to describe possible causes and consequences. We found that although there are important differences in the epidemiology of cutaneous lymphomas in different countries, the relative frequency of certain, especially rare lymphomas remains stable. Several studies described growing incidences of both CTCL and CBCL. The emergence of new diagnostic criteria, a more precise definition of the entities and new biomarkers enable a better classification of cases.

New biotherapies for the treatment of cutaneous T-cell lymphomas

Most cutaneous lymphomas are cutaneous T-cell lymphomas, and the most common form is mycosis fungoides. Sézary syndrome is a leukemic form of cutaneous T-cell lymphoma which is characterized by erythroderma and the presence of blood tumor cells. The only potential cure of cutaneous T-cell lymphomas remains allogeneic stem cell transplantation. However, monoclonal antibodies have led to a substantial progress in the treatment of advanced-stage cutaneous T-cell lymphomas. Some of them, such as mogamulizumab (anti-CCR4 monoclobal antibody) or brentuximab vedotin (anti-CD30 coupled to monomethylauristatin E, antibody drug conjugate) have shown efficacy in international randomized controlled studies. Lacutamab, an anti-KIR3DL2 monoclonal antibody, is currently tested in an international, prospective phase 2 trial in cutaneous T-cell lymphomas and peripheral T-cell lymphomas. Finally, immune checkpoint inhibitors have shown clinical benefit in open-label phase 2 studies in cutaneous T-cell lymphomas. This review focuses on the new biotherapies currently used in cutaneous T-cell lymphomas.

[Current therapeutic options in Mycosis fungoides and Sézary syndrome]

Driven by the approval of new targeted therapies, significant progress has been made in recent years in the clinical management of cutaneous T‑cell lymphomas. Although there are no curative treatment options for cutaneous T‑cell lymphomas, response rates are often encouraging, in particular when using combination therapies. The decision for the appropriate form of treatment depends on the specific diagnosis, disease stage, and the history of prior therapies. This article provides a comprehensive overview of current treatment options in mycosis fungoides and Sézary syndrome, based on the recently published, revised German S2k guidelines on cutaneous lymphomas (update 2021). In addition, we present promising, yet-to-be-approved therapies that at least in part can be already used off-label in clinical practice today.

Clinical characteristics and prognostic factors of 70 patients with Sézary syndrome: a single-institutional experience at Moffitt cancer center

Sézary syndrome (SS) is a rare and aggressive leukemic variant of cutaneous T-cell lymphoma, with a median overall survival (OS) rate of 2-4 years. Few studies have described the clinical outcome of SS patients since 2012. We retrospectively analyzed 70 patients diagnosed with SS treated at a high-volume tertiary cancer center between 2000 and 2018. Overall survival at 1 and 5 years was 84.1% and 50.7%, respectively. Univariate analyses identified older age (>65 years) and male sex as poor prognostic factors. Five patients presented with circulating large granular lymphocytic proliferation and had a favorable prognosis. Targeted therapies were effective in treating refractory/relapsed SS patients with a durable response. Therapeutic advancements and the comprehensive treatments used in a multidisciplinary clinic improved OS rates.

Mogamulizumab efficacy is underscored by its associated rash that mimics cutaneous T-cell lymphoma: a retrospective single-centre case series

BACKGROUND

Mogamulizumab is a humanized antibody against chemokine receptor type 4. It was recently approved by the US Food and Drug Administration for relapsed or refractory mycosis fungoides (MF) and Sézary syndrome (SS). The most commonly reported adverse event in the phase III licensing trial was drug eruption (28%), now termed mogamulizumab-associated rash (MAR). Clinical recommendations about MAR and its treatment differ between the current package insert and postapproval insights reported from two single-centre studies that focused on its characterization, but less so on outcomes and clinicopathological differentiation from cutaneous T-cell lymphoma (CTCL).

OBJECTIVES

To describe our experience in the diagnosis of MAR and treatment of patients with CTCL with mogamulizumab.

METHODS

This is a single-centre retrospective case series study.

RESULTS

We found a higher incidence of MAR in patients with CTCL (17 of 24, 68%) than previously reported. MAR development is associated with complete (11 of 17) or partial (four of 17) responses, with an overall response rate of 88%, compared with 29% (two of seven) in patients without MAR. Diagnosis of MAR may be obscured by its ability to mimic key CTCL features both clinically and histologically, but an absence of T-cell-receptor clonality and relatively decreased CD4 : CD8 ratio compared with baseline lesions strongly favour MAR over recurrent disease.

CONCLUSIONS

MAR has the potential to create a significant management problem for patients on mogamulizumab. Misidentification of MAR as recurrent CTCL may detrimentally result in the premature discontinuation of mogamulizumab in patients whose disease is historically hard to treat. Thorough clinicopathological investigation of new lesions during treatment with mogamulizumab is required to inform ideal treatment decisions and achieve better outcomes.

Lack of PRAME Expression in Cutaneous T-Cell Lymphomas

Cutaneous T-cell lymphomas (CTCLs) are rare tumors with no established markers that can reliably distinguish between benign and malignant lesions. Preferentially Expressed Antigen in Melanoma (PRAME) is a cancer/testis antigen that is found in many solid and hematologic malignancies. PRAME overexpression typically portends a poor prognosis and lower chemotherapeutic response. To date, no studies have established a role for PRAME in CTCL. An analysis was performed on 47 cases definitively diagnosed as CTCL: 25 cases of mycosis fungoides, 2 of Sezary syndrome, 5 of CD30+ lymphoproliferative disorder, 7 of primary cutaneous anaplastic large T-cell lymphoma, 3 of primary cutaneous CD4+ small/medium T-cell lymphoproliferative disorder, 1 of subcutaneous panniculitis-like T-cell lymphoma, and 4 of angiocentric T-cell lymphoma. PRAME immunohistochemistry was completely negative in all cases. PRAME expression was not found in any CTCL subtypes, suggesting that the pathogenesis of CTCL is not mediated by PRAME. Further study is required to identify biomarkers that might aid in the diagnosis and prognostication of CTCLs.

Proteomic Screening and Verification of Biomarkers in Different Stages of Mycosis Fungoides: A pilot Study

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma; in advanced stages, it can involve multiple organs and has a poor prognosis. Early detection of the disease is still urgent, but there is no optimal therapy for advanced MF. In the present study, quantitative proteomic analyses (label-free quantitation, LFQ) were applied to tissue samples of different stages of MF and tissue samples from controls (eczema patients and healthy donors) to conduct preliminary molecular analysis to clarify the pathogenesis of the disease. Differential protein expression analysis demonstrated that 113 and 305 proteins were associated with the early and advanced stages of MF, respectively. Gene ontology (GO) enrichment analysis was conducted to determine the potential functions of the proteins, which could be classified into three categories: biological process, cellular component, and molecular function. The results revealed that a series of biological processes, including “initiation of DNA replication” and “nucleosome assembly,” were involved in the disease. Moreover, cellular components, including the “desmosome” and “integrin complex,” may affect the invasion and metastasis of MF via molecular functions, including “integrin binding” and “cadherin binding”. Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis demonstrated that “focal adhesion DNA replication,” “Toll-like receptor signalling pathway” and other pathways were also involved. A parallel reaction monitoring (PRM) assay was applied to validate the identified differentially expressed proteins. In conclusion, the above proteomic findings may have great diagnostic and prognostic value in diverse malignancies, especially MF. Nevertheless, further studies are still needed to explore the precise mechanisms of MF.

Contemporary Treatment Patterns and Response in Relapsed/Refractory Cutaneous T-Cell Lymphoma (CTCL) across Five European Countries

The treatment pattern of cutaneous T-cell lymphoma (CTCL) remains diverse and patient-tailored. The objective of this study was to describe the treatment patterns and outcomes in CTCL patients who were refractory or had relapsed (R/R) after a systemic therapy. A retrospective chart review study was conducted at 27 sites in France, Germany, Italy, Spain and the United Kingdom (UK) of patients who received a first course of systemic therapy and relapsed or were refractory. Data were collected longitudinally from diagnosis to first-, second- and third-line therapy. The study included 157 patients, with a median follow-up of 3.2 years. In total, 151 proceeded to second-line and 90 to third-line therapy. In the first line (n = 147), patients were treated with diverse therapies, including single- and multi-agent chemotherapy in 67 (46%), retinoids in 39 (27%), interferon in 31 (21%), ECP in 4 (3%), corticosteroids in 3 (2%) and new biological agents in 3 (2%). In the second line, the use of chemotherapy and retinoids remained similar to the first line, while the use of new biologics increased slightly. In sharp contrast to the first line, combination chemotherapy was extremely diverse. In the third line, the use of chemotherapy remained high and diverse as in the second line. From the time of first R/R, the median PFS was 1.2 years and the median OS was 11.5 years. The presented real-world data on the current treatments used in the management of R/R CTCL in Europe demonstrate the significant heterogeneity of systemic therapies and combination therapies, as expected from the European guidelines.

Oncogenic Mutations and Gene Fusions in CD30-Positive Lymphoproliferations and Clonally Related Mycosis Fungoides Occurring in the Same Patients

The emergence of a common progenitor cell has been postulated for the association of CD30-positive lymphoproliferative disease (LPD) and mycosis fungoides (MF) within the same patient. Up to now, no comprehensive analysis has yet addressed the genetic profiles of such concurrent lymphoma subtypes. We aimed to delineate the molecular alterations of clonally related CD30-positive LPD and MF occurring in the same two patients. We analyzed the molecular profile of 16 samples of two patients suffering both from CD30-positive LPD and MF being obtained over a time course of at least 5 years. To detect oncogenic mutations, we applied targeted sequencing technologies with a hybrid capture-based DNA library preparation approach, and for the identification of fusion transcripts, an anchored multiplex PCR enrichment kit was used. In all samples of CD30-positive LPD and MF, oncogenic fusions afflicting the Jak/signal transducer and activator of transcription signaling pathway were present, namely NPM1‒TYK2 in patient 1 and ILF3‒JAK2 in patient 2. Additional signal transducer and activator of transcription 5A gene STAT5A mutations exclusively occurred in lesions of CD30-positive LPD in one patient. CD30-positive LPD and MF may share genetic events when occurring within the same patients. Constitutive activation of the Jak/signal transducer and activator of transcription signaling pathway may play a central role in the molecular pathogenesis of both entities.

High Expression of IKZF2 in Malignant T Cells Promotes Disease Progression in Cutaneous T Cell Lymphoma

Cutaneous T cell lymphoma is a generally indolent disease derived from skin-homing mature T cells. However, in advanced stages, cutaneous T cell lymphoma may manifest aggressive clinical behaviour and lead to a poor prognosis. The mechanism of disease progression in cutaneous T cell lymphoma remains unknown. This study, based on a large clinical cohort, found that IKZF2, an essential transcription factor during T cell development and differentiation, showed stage-dependent overexpression in the malignant T cells in mycosis fungoides lesions. IKZF2 is specifically over-expressed in advanced-stage mycosis fungoides lesions, and correlates with poor prognosis. Mechanistically, overexpression of IKZF2 promotes cutaneous T cell lymphoma progression via inhibiting malignant cell apoptosis and may contribute to tumour immune escape by downregulating major histocompatibility complex II molecules and up-regulating the production of anti-inflammatory cytokine interleukin-10 by malignant T cells. These results demonstrate the important role of IKZF2 in high-risk cutaneous T cell lymphoma and pave the way for future targeted therapy.