A retrospective study of prognostic factors and treatment outcome in advanced-stage Mycosis Fungoides and Sezary Syndrome.

Background: Mycosis fungoides (MF) and Sezary Syndrome (SS) comprise over half of all Cutaneous T-cell lymphoma diagnoses. Current risk stratification is largely based on TNMB staging, few research investigated the prognostic value of clinical exams. Current systemic therapy for advanced disease includes immunomodulatory drugs, chemotherapy, and HADC inhibitors. Few clinical trials or retrospective research compared the efficacy of different drugs.Method: Here, we performed a retrospective analysis of prognostic factors and treatment outcomes of 92 patients diagnosed with MF/SS at the Peking Union Medical College Hospital from 2013-2023.Results: Cox regression analysis identified that age ≥ 50 years, WBC ≥ 8 × 109/L, serum LDH ≥ 250U/L, ß2-MG ≥ 4.50 mg/L, and stage IV were associated with reduced overall survival, age ≥ 50 years, serum LDH ≥ 250U/L and stage IV were associated with reduced progression free survival. Kaplan-Meier analysis established that immunomodulatory therapy was associated with longer progression free survival.Conclusion: These results suggested new factors in predicting prognosis and selecting appropriate treatments in patients with advanced MF/SS.

The Impact of Primary Tumor Site on Survival in Mycosis Fungoides.

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma (CTCL), but little is known about the influence of anatomic location of the primary disease site on overall survival (OS) and disease-specific survival (DSS). The purpose of this study was to examine the significance of primary tumor site on survival in MF. A search of the Surveillance, Epidemiology, and End Results (SEER) database was conducted for patients with a diagnosis of MF with a specified primary site from 2000 to 2019. Prognostic factors including demographic and tumor characteristics were examined using Cox regression models. Further research is needed to fully investigate primary disease site as a prognostic indicator, including a deeper dive into MF of all stages and subtypes.

Long term outcomes of nonmyeloablative allogeneic stem cell transplantation with TSEB TLI and ATG for Mycosis Fungoides and Sezary Syndrome.

Advanced stage (IIB-IVB) Mycosis Fungoides (MF) and Sezary Syndrome (SS) have a poor prognosis with median survival <5 years. We report long-term outcomes of a non-myeloablative allogeneic stem cell transplantation regimen consisting of total skin electron beam therapy, total lymphoid irradiation and antithymocyte globulin. Our prospective cohort consisted of 41 patients with a higher proportion of MF (34MF, 7SS). Acute GVHD Grade 2 to 4 was seen in 31.7% and chronic GVHD Grade 2 to 4 in 24%. The cumulative incidence of non-relapse mortality was 9.8% at 1 year and 12.6% at 2 years. At Day +90 post-transplant 66% of patients had a complete response (CR). With a median post-transplant follow up of 5.27 years, the 5-year overall survival rate was 37.7% (MF 36.7%, SS 57.1%). The 5-year cumulative incidence of progressive disease or relapse was 52.7% in all patients but only 20.8% in those with CR at transplant compared to 70.6% in those not in CR at transplant (p = 0.006). Long term survival is possible in advanced MF and SS with non-myeloablative transplantation and outcomes are improved in patients with CR at transplant.

Genomic profiling of mycosis fungoides identifies patients at high risk of disease progression.

ABSTRACT: Mycosis fungoides (MF) is the most prevalent primary cutaneous T-cell lymphoma, with an indolent or aggressive course and poor survival. The pathogenesis of MF remains unclear, and prognostic factors in the early stages are not well established. Here, we characterized the most recurrent genomic alterations using whole-exome sequencing of 67 samples from 48 patients from Lille University Hospital (France), including 18 sequential samples drawn across stages of the malignancy. Genomic data were analyzed on the Broad Institute's Terra bioinformatics platform. We found that gain7q, gain10p15.1 (IL2RA and IL15RA), del10p11.22 (ZEB1), or mutations in JUNB and TET2 are associated with high-risk disease stages. Furthermore, gain7q, gain10p15.1 (IL2RA and IL15RA), del10p11.22 (ZEB1), and del6q16.3 (TNFAIP3) are coupled with shorter survival. Del6q16.3 (TNFAIP3) was a risk factor for progression in patients at low risk. By analyzing the clonal heterogeneity and the clonal evolution of the cohort, we defined different phylogenetic pathways of the disease with acquisition of JUNB, gain10p15.1 (IL2RA and IL15RA), or del12p13.1 (CDKN1B) at progression. These results establish the genomics and clonality of MF and identify potential patients at risk of progression, independent of their clinical stage.

Risk of progression of early-stage mycosis fungoides, 10-year experience.

BACKGROUND: Mycosis fungoides is the most frequent form of cutaneous T-cell lymphoma. It is characterized by a chronic, slow, and progressive course, and is associated with mortality rates that depend on several factors, such as clinical staging. A median survival time of up to 13 months is found in patients with advanced stages that require more aggressive treatments, with greater toxicity and higher costs. In Latin America, few prognostic studies of the disease are available. OBJECTIVE: To determine the rate of progression from early stages (IA, IB, IIA) to more advanced stages (> IIB) in patients older than 18 years with mycosis fungoides treated at two medical centers in Colombia between January 1, 2010, and December 31, 2019. METHODS: Retrospective cohort study with a longitudinal design. RESULTS: 112 patients diagnosed with early mycosis fungoides were included. 56.2% were male (n = 63), with a median age of 53 years (IQR 43‒67). The most frequent clinical variant was classic (67.9%; n = 76), followed by folliculotropic (16%; n = 18), and hypopigmented (10.7%; n = 12). The most common first-line treatment was NB-UVB phototherapy (27.7%; n = 31), followed by PUVA phototherapy (25.8%; n = 29%), and topical corticosteroids (25%; n = 28). The global rate of disease progression was 8% (n = 9), with an overall mortality of 12.5% (n = 14). STUDY LIMITATIONS: Its retrospective design and the lack of molecular studies for case characterization. CONCLUSIONS: Early mycosis fungoides is a disease with a good prognosis in most patients, with a progression rate of 8% (n = 9).

Análisis de supervivencia en pacientes con micosis fungoide foliculotropa de un centro latinoamericano / Folliculotropic Mycosis Fungoides in a Latin American Hospital: Survival Analysis

Introducción La micosis fungoide foliculotropa es una variante de mal pronóstico y presentación clínica variada. Se ha planteado que la estadificación TNMB usada para esta neoplasia no es útil. En una propuesta reciente basada en aspectos clínicos e histológicos, se clasifica en enfermedad temprana y avanzada, encontrando diferencias pronósticas entre las 2categorías. El objetivo de este estudio fue comparar la supervivencia de estos 2 grupos en nuestra población. Materiales y métodos Se realizó un estudio observacional retrospectivo de serie de casos donde se evaluó la evolución clínica de los pacientes con micosis fungoide foliculotropa tratados en el Instituto Nacional de Cancerología entre el 2008 y el 2020, realizando un análisis comparativo de supervivencia entre aquellos que tienen enfermedad temprana y enfermedad avanzada. Resultados Se incluyó a un total de 21 pacientes, 11 de los cuales presentaban enfermedad temprana y 10 enfermedad avanzada. Se identificaron 7 decesos, todos ellos en los pacientes con enfermedad avanzada. La supervivencia global de la población total a 5 años fue del 62%, mientras que para la población con enfermedad avanzada fue del 40%. No hubo diferencias en la supervivencia según la estadificación TNMB. Conclusión La estadificación TNMB no es útil para los pacientes con una micosis fungoide foliculotropa. Por el contrario, la nueva clasificación clínico-patológica parece brindar información pronóstica fiable y permite tomar medidas terapéuticas acordes (AU)

Introduction Folliculotropic mycosis fungoides is a variant that has poor prognosis and a variable clinical presentation. Concerns have been expressed that the current TNMB staging of this tumor may not be useful. A recently developed classification system based on clinical and histologic variables classifies this tumor as early or advanced, a distinction found to correlate with prognosis. The aim of this study was to compare survival in FMF in Colombia between patients with early versus advanced tumors. Material and methods Retrospective, observational study of clinical course and outcomes in patients with FMF treated at the National Cancer Institute of Colombia between 2008 and 2020. Survival was compared between early and advanced disease. Results Twenty-one patients (11 with early FMF and 10 with advanced FMF) were studied. Seven patients, all with advanced disease, died. Survival at 5 years was 62% overall and 40% for patients with advanced FMF. No differences were observed when survival was analyzed according to TNMB stage. Conclusions TNMB staging is not useful in FMF. The new classification system based on clinicopathologic features appears to provide reliable information for assessing prognosis and guiding treatment decisions (AU)

[Translated article] Folliculotropic Mycosis Fungoides in a Latin American Hospital: Survival Analysis / Análisis de supervivencia en pacientes con micosis fungoide foliculotropa de un centro latinoamericano

Introduction Folliculotropic mycosis fungoides is a variant that has poor prognosis and a variable clinical presentation. Concerns have been expressed that the current TNMB staging of this tumor may not be useful. A recently developed classification system based on clinical and histologic variables classifies this tumor as early or advanced, a distinction found to correlate with prognosis. The aim of this study was to compare survival in FMF in Colombia between patients with early versus advanced tumors. Material and methods Retrospective, observational study of clinical course and outcomes in patients with FMF treated at the National Cancer Institute of Colombia between 2008 and 2020. Survival was compared between early and advanced disease. Results Twenty-one patients (11 with early FMF and 10 with advanced FMF) were studied. Seven patients, all with advanced disease, died. Survival at 5 years was 62% overall and 40% for patients with advanced FMF. No differences were observed when survival was analyzed according to TNMB stage. Conclusions TNMB staging is not useful in FMF. The new classification system based on clinicopathologic features appears to provide reliable information for assessing prognosis and guiding treatment decisions (AU)

Introducción La micosis fungoide foliculotropa es una variante de mal pronóstico y presentación clínica variada. Se ha planteado que la estadificación TNMB usada para esta neoplasia no es útil. En una propuesta reciente basada en aspectos clínicos e histológicos, se clasifica en enfermedad temprana y avanzada, encontrando diferencias pronósticas entre las 2categorías. El objetivo de este estudio fue comparar la supervivencia de estos 2 grupos en nuestra población. Materiales y métodos Se realizó un estudio observacional retrospectivo de serie de casos donde se evaluó la evolución clínica de los pacientes con micosis fungoide foliculotropa tratados en el Instituto Nacional de Cancerología entre el 2008 y el 2020, realizando un análisis comparativo de supervivencia entre aquellos que tienen enfermedad temprana y enfermedad avanzada. Resultados Se incluyó a un total de 21 pacientes, 11 de los cuales presentaban enfermedad temprana y 10 enfermedad avanzada. Se identificaron 7 decesos, todos ellos en los pacientes con enfermedad avanzada. La supervivencia global de la población total a 5 años fue del 62%, mientras que para la población con enfermedad avanzada fue del 40%. No hubo diferencias en la supervivencia según la estadificación TNMB. Conclusión La estadificación TNMB no es útil para los pacientes con una micosis fungoide foliculotropa. Por el contrario, la nueva clasificación clínico-patológica parece brindar información pronóstica fiable y permite tomar medidas terapéuticas acordes (AU)

Association of marital status with stage and survival in patients with mycosis fungoides: A population-based study.

BACKGROUND: Previous studies have shown that marital status was associated with stages and survival in patients with melanoma or Merkel cell carcinoma. To date, the impacts of marital status on stage and survival in patients with mycosis fungoides (MF) have not been determined yet. METHODS: A total of 3375 eligible cases diagnosed from 2004 to 2015 were included from the Surveillance, Epidemiology, and End Results (SEER) database. Association of marital status with stage and survival in patients with MF was analyzed. RESULTS: Married patients were more likely to be diagnosed at T1 stage (p = 0.041). And married patients were less likely to present with lymph node involvement (p = 0.007). More favorable overall survival (p < 0.001) and cancer-specific survival (p < 0.001) were demonstrated in married patients as compared with divorced patients or widowed patients. A clinically feasible prognostic model including marital status, age, sex, race, and stage at presentation was constructed. CONCLUSION: Married marital status was associated with earlier stage at diagnosis and longer survival compared with divorced or widowed marital status in patients with MF.

Mycosis Fungoides and Sézary Syndrome: Updates and Review of Current Therapy.

OPINION STATEMENT: While most patients with early-stage mycosis fungoides (MF) follow an indolent course, patients with advanced-stage MF/Sézary syndrome (SS) have a poor prognosis with a median survival of less than 5 years. Although there are a number of treatments currently available, achieving and maintaining a durable response remain challenging, especially in advanced-stage MF/SS. The choice of frontline therapy is dependent on the stage of disease. For early-stage MF, the treatment concept is to control skin lesions mainly by skin-directed therapies, such as topical therapies, phototherapies, and radiotherapies. For advanced-stage MF/SS, systemic treatments by biological or targeted therapies including bexarotene and interferon either alone or in combination are tried first, with more immunosuppressive chemotherapies being reserved for refractory or rapidly progressive disease. Recent improvements in biological or targeted therapies include brentuximab vedotin and mogamulizumab. When biopsy samples have 10% or more CD30-positive malignant cells, brentuximab vedotin, an anti-CD30 antibody conjugated to monomethyl auristin E, can be a desirable treatment option. For cases with blood involvement, mogamulizumab, an antibody binding to C-C chemokine receptor 4, is effective with high response rates. In the refractory setting, alemtuzumab, histone deacetylase inhibitors, pralatrexate, gemcitabine, and doxorubicin are considered as the treatment option. Because only allogeneic hematopoietic stem cell transplantation can offer a chance of cure with durable complete remission, advanced-stage patients with a markedly short life expectancy should be evaluated for eligibility. Given that there are few randomized controlled studies in the literature, it is necessary to investigate which therapy is preferable for each patient with MF/SS by comparative prospective trials.

Role of chromatin assembly factor-1/p60 and poly [ADP-ribose] polymerase 1 in mycosis fungoides.

Mycosis fungoides (MF) represents the most common type of cutaneous lymphoma. In the majority of patients, the disease has a slow evolution and a protracted course; however, a subset of patients shows poor oncologic outcomes. Unfortunately, there are no reliable prognostic markers for MF, and the currently available treatments are only effective in a minority of patients. This study aimed to evaluate the expression and clinical significance of PARP-1 and CAF-1/p60 in MF. Sixty-four MF representatives of the different stages of disease were assessed by immunohistochemistry for PARP-1 and CAF-1/p60. The association of PARP-1 and CAF-1/p60 with the MF stage and outcome was assessed by using Fisher's exact test and Kaplan-Meier survival analysis with the Log-rank test; a p value < 0.05 was considered significant. PARP-1 was overexpressed in 57.9% of MF and was significantly associated with a MF stage > II (p = 0.034) but not with the risk of death (p = 0.237). CAF-1/p60 was overexpressed in 26.8% of MF and was significantly associated with decreased overall survival (p < 0.001) but not with the MF stage (p = 1). A significant association was found between PARP-1 overexpression and CAF-1/p60 overexpression (p = 0.0025). Simultaneous overexpression of PARP-1 and CAF-1/p60 was significantly associated with decreased overall survival (p < 0.001), although less strongly than CAF-1/p60 alone (χ2 = 14.916 vs 21.729, respectively). In MF, PARP-1 is overexpressed in advanced stages, while CAF-1/p60 is overexpressed in the cases with shorter overall survival, appearing as a significant prognostic marker. A role for PARP-1 inhibitors and anti-CAF-1/p60 targeted therapy may be reasonably hypothesized in MF.

Differential SATB1 Expression Reveals Heterogeneity of Cutaneous T-Cell Lymphoma.

SATB1 is an important T-cell specific chromatin organizer in cutaneous T-cell lymphoma, whereas its expression and function in mycosis fungoides (MF) remain ambiguous. Our study aimed to investigate the clinicopathological significance of SATB1 in a cohort of 170 patients with MF. SATB1 expression was heterogeneous among the patients with MF in each clinical stage. High SATB1 expression was associated with epidermal hyperplasia, eosinophil infiltration, less large-cell transformation, and favorable prognosis in MF cases. SATB1 and CD30 coexpression distinguished cutaneous CD30+ lymphoproliferative disorders from MF large-cell transformation. SATB1 silencing in MF lines showed that SATB1 upregulated the genes involved in eosinophil recruitment, including signal transducer and activator of transcription 3 and IL13, and downregulated the genes in cell-cycle progression, which may explain the inferior prognosis for low SATB1-expressing cases. Moreover, SATB1 was inversely correlated with PD-1 expression, indicating an exhausted status of SATB1-negative malignant T cells. SATB1 was positively correlated with toll-like receptors expression, suggesting innate immune activation in high SATB1-expressing MF cases. Therefore, variable SATB1 expression promotes heterogeneity in pathology and clinical outcome of patients with MF.

Mycosis fungoides and Sézary syndrome: Australian clinical practice statement.

Primary cutaneous lymphomas represent a heterogeneous group of T- and B-cell lymphomas with distinct clinical presentations, histopathologic features, treatment approaches and outcomes. The cutaneous T-cell lymphomas, which include mycosis fungoides and Sézary syndrome, account for the majority of the cutaneous lymphomas. This Clinical Practice Statement is reflective of the current clinical practice in Australia. An expanded form of the Clinical Practice Statement (and updates), along with helpful patient resources and access to support groups, can be found at the following (http://www.australasianlymphomaalliance.org.au).

Phenotypical Markers, Molecular Mutations, and Immune Microenvironment as Targets for New Treatments in Patients with Mycosis Fungoides and/or Sézary Syndrome.

Primary cutaneous lymphomas encompass a wide spectrum of rare lymphoproliferative disorders originating in the skin, among which, mycosis fungoides (MF) is the most common subtype. The treatment of this disease is based on skin-directed therapies eventually in association with biologic response modifiers in the early phases, whereas in patients with the advanced stages, several therapeutic strategies can be used including mono and/or polychemotherapy and bone marrow transplantation. In recent years, the identification of specific markers (phenotypical, immunological, and molecular) has led to the development of several studies (including two randomized phase III trials). The results of these studies are modifying our therapeutic strategy toward a personalized treatment approach in which the clinical characteristics of the patients and tumor-node-metastasis-blood stage are considered together with the expression of specific markers (i.e., a CD30-positive expression for the use of brentuximab vedotin). This review will provide a comprehensive scenario of the main phenotypical, molecular, and immunological markers related to MF pathogenesis and disease evolution, which could represent the target for the development of innovative effective treatments in this disease.

The immunopathogenesis and immunotherapy of cutaneous T cell lymphoma: Pathways and targets for immune restoration and tumor eradication.

Cutaneous T cell lymphomas (CTCLs) are malignancies of skin-trafficking T cells. Patients with advanced CTCL manifest immune dysfunction that predisposes to infection and suppresses the antitumor immune response. Therapies that stimulate immunity have produced superior progression-free survival compared with conventional chemotherapy, reinforcing the importance of addressing the immune deficient state in the care of patients with CTCL. Recent research has better defined the pathogenesis of these immune deficits, explaining the mechanisms of disease progression and revealing potential therapeutic targets. The features of the malignant cell in mycosis fungoides and Sézary syndrome are now significantly better understood, including the T helper 2 cell phenotype, regulatory T cell cytokine production, immune checkpoint molecule expression, chemokine receptors, and interactions with the microenvironment. The updated model of CTCL immunopathogenesis provides understanding into clinical progression and therapeutic response.

Survival prediction model for patients with mycosis fungoides/Sezary syndrome.

Aim: A nomogram was constructed to forecast the overall survival (OS) of patients with mycosis fungoides/Sezary syndrome. Patients & methods: The clinicopathological information of patients was obtained from the Surveillance, Epidemiology and End Results (SEER) database. A model was established based on the independent prognostic factors. Predictive ability of the model was evaluated with the concordance index and calibration curves. Risk stratification was conducted for patients with similar tumor node metastasis (TNM) stages. Results: The model included 1997 eligible patients and seven prognostic factors for OS. The concordance index of the nomogram was 0.84 in the training and external validation cohorts, which indicated good predictive ability of the model and reliability of the results. The high agreement between the model predictions and actual observations was identified by calibration curves, which demonstrated the prediction accuracy of the model. Risk stratification displayed significant differences for patients with similar TNM stages, which suggested that the OS of patients with similar TNM stages could be further distinguished. Conclusion: We established a reliable nomogram to predict the OS of patients with mycosis fungoides/Sezary syndrome, which highlighted the advantages of nomograms over the conventional TNM staging system and promoted the application of individualized therapeutic strategies.

Outcome of allogeneic hematopoietic stem cell transplantation for mycosis fungoides and Sézary syndrome.

Although allogeneic hematopoietic stem cell transplantation (HSCT) has been reported to provide prolonged remission of relapsed/refractory mycosis fungoides (MF) and Sézary syndrome (SS), its role has not been fully evaluated. Here, the outcomes of allogeneic HSCT for patients with MF/SS were retrospectively evaluated by using the registry database of the Japan Society for Hematopoietic Cell Transplantation. Forty-eight patients were evaluable and enrolled in the analysis. Median age was 45.5 years. Eighteen patients (38%) received myeloablative conditioning, and 33 (69%) received HSCT from an alternative donor. Disease status was complete or partial response in 25% of the patients and relapsed or refractory in the others. At the time of analysis, 18 patients were alive, with a median follow-up of 31.0 months (range, 3.8-31.1). Three-year overall survival (OS) and progression-free survival (PFS) were 30% (95%CI, 16-45%) and 19% (95%CI, 9-31%), respectively. Disease progression was not observed later than 17 months after transplantation. Both disease status and performance status at transplant significantly affected OS and PFS. Although our findings suggest that allogeneic HSCT provides long-term PFS in patients with MF/SS, the timing of transplantation should be decided carefully based on the disease status and the patient's condition in order to improve the outcome.

Plaque stage folliculotropic mycosis fungoides: histopathologic features and prognostic factors in a series of 40 patients.

BACKGROUND: Folliculotropic mycosis fungoides (FMF) is a distinct variant of mycosis fungoides. Recent studies recognized indolent and aggressive subgroups of FMF, but there is controversy how patients presenting with plaques should be classified. The present study describes the histopathologic features of 40 FMF plaques. The aim of the study was to identify risk factors for disease progression and poor outcome in this group. METHODS: Clinical, histopathological, and immunophenotypical data from 40 patients with plaque stage FMF were reviewed and analysed for risk factors for disease progression and survival. RESULTS: After a median follow-up of 80 months, disease progression occurred in 20 of 40 patients. Percentage of atypical cells, cell size, percentage of Ki-67+ cells, and co-existent interfollicular epidermotropism, but not the extent of perifollicular infiltrates, were associated with disease progression and reduced survival, while extensive follicular mucinosis was associated with increased survival. CONCLUSIONS: This study underlines that FMF patients presenting with plaques represent a heterogeneous group and that a subgroup of these patients may have an indolent clinical course. It further shows that histological examination is a valuable tool to differentiate between indolent and aggressive disease.

Radiotherapy Eradicates Malignant T Cells and Is Associated with Improved Survival in Early-Stage Mycosis Fungoides.

PURPOSE: Mycosis fungoides is the most common subtype of cutaneous T-cell lymphoma. Skin-directed treatments often improve but do not cure mycosis fungoides skin lesions. The purpose of this study was to (i) assess whether remission was associated with malignant T-cell clone depletion at treated sites using either low-dose radiotherapy (LDRT, 8 Gy) or topical steroids and (ii) assess whether a clone-ablative therapy, like LDRT, is associated with overall survival in patients with high-risk early-stage CTCL. EXPERIMENTAL DESIGN: Pre- and posttreatment biopsies from 20 lesional skin samples of 18 patients with mycosis fungoides who received either 8 Gy LDRT (n = 16) or topical steroids (n = 4) underwent high-throughput T-cell receptor sequencing of the TCRB gene to quantify the malignant T-cell clone. For the retrospective chart review, overall survival of 47 high-risk early-stage patients was compared between patients who did or did not receive radiation. RESULTS: LDRT eradicated the clone in 5 of 16 lesions and reduced it >90% in 11 of 16; there were no recurrences in these lesions. Patients treated with topical steroids appeared to clinically improve, but the malignant clone persisted. We found that the number of residual malignant T cells predicted lesion recurrence. A retrospective review showed that early-stage high-risk patients who received radiation as part of their treatment regimen had prolonged overall survival compared with patients who did not. CONCLUSIONS: These findings demonstrate that LDRT can eradicate malignant T cells in mycosis fungoides, provides robust disease control, and is associated with improved survival in high-risk early-stage patients.

Efficacy of Allogeneic Hematopoietic Cell Transplantation in Cutaneous T Cell Lymphoma: Results of a Systematic Review and Meta-Analysis.

Mycosis fungoides and Sézary syndrome are the most common types of primary cutaneous T cell lymphomas. The clinical presentation of mycosis fungoides is generally indolent, whereas Sézary syndrome represents a more aggressive disease variant. Stage at diagnosis is the most important determinant of long-term survival outcome. Although most patients present with early-stage disease, those who develop progressive disease or have an advanced stage represent a therapeutic challenge because of a lack of effective therapies. Allogeneic hematopoietic cell transplantation (allo-HCT) has been used as a potentially curative treatment modality with encouraging long-term outcomes. However, a lack of randomized controlled data remains, and the published literature is limited to mostly retrospective studies. We performed a comprehensive search of the medical literature using PubMed/Medline, EMBASE, and Cochrane reviews on September 13, 2018. We extracted data on clinical outcomes related to benefits (overall [OS] and progression-free [PFS] survival) and harms (relapse and nonrelapse mortality [NRM]) independently by 2 authors. Our search strategy identified 289 references. Five studies (266 patients) were included in this systematic review and meta-analysis. Reduced-intensity and nonmyeloablative regimens were more commonly prescribed (76%). Mobilized peripheral blood stem cells were the preferred graft source (78%). The pooled OS and PFS rates were 59% (95% confidence interval [CI], 50% to 69%) and 36% (95% CI, 27% to 45%), respectively. Pooled relapse rate was 47% (95% CI, 41% to 53%) and pooled NRM rate 19% (95% CI, 13% to 27%). Results of this systematic review and meta-analysis show that allo-HCT yields encouraging OS and PFS rates; however; relapse remains a significant cause of allo-HCT failure. Novel strategies to further improve outcomes should focus on offering allo-HCT before the development of resistant disease and reducing relapse by incorporating post-transplant maintenance therapies.