Outcomes and prognostic factors in African American and black patients with mycosis fungoides/Sézary syndrome: Retrospective analysis of 157 patients from a referral cancer center

Racial Disparities in Mycosis Fungoides/Sézary Syndrome-A Single-Center Observational Study of 292 Patients

BACKGROUND

Clinical presentation of Mycosis fungoides/Sézary syndrome (MF/SS) in Black and African American (AA) patients can be heterogeneous with poor survival reported in AA/black patients. In this study, we aim to characterize differences between AA/black and white patients with MF/SS.

PATIENTS AND METHODS

A retrospective single-center hospital-based case-control study including 292 MF/SS patients (146 AA/black matched with 146 white patients). We analyzed demographic, clinical and survival differences.

RESULTS

AA/black patients were diagnosed at an earlier age (9 years younger), were predominantly females, had higher rates of Medicaid/Medicare insurance and lower income compared to matched white patients (P <.001). Adjusting for age, sex, insurance type, and income bracket, AA/black patients had significantly worse overall survival (hazard ratio [HR] 2.88, 95%CI 1.21-6.85, P = .017). Association of clinical MF phenotype with survival showed that hypopigmentation was associated with survival in AA/black patients but not in white patients. Erythroderma and ulceration were associated with worse survival risk in AA/black patients.

CONCLUSIONS

AA/black patients with MF/SS have a significant worse survival outcome compared to white patients. The association between clinical phenotypes and survival differed between these groups. Further studies are required to investigate whether race-specific pathogenesis or genetic factors may explain these differences.

Evaluation of the prognostic significance of clinical features of tumoral lesions in an extensive series of mycosis fungoides

BACKGROUND

Tumors indicating the advanced stage of mycosis fungoides (MF) have a rich clinical spectrum. Although it is known that the prognosis of MF generally worsens following the development of tumors, some cases may have a relatively indolent course, and the role of clinical characteristics regarding prognosis has still not been well understood.

METHODS

MF patients were retrospectively evaluated regarding the development of tumors. Besides demographic characteristics, data of the subtype and stage of the disease were recorded. The clinical features of tumors, including number (<5, 5-10, 11-20, or >20), location, dimension (diameter of ≥5 cm), presence of ulceration, and surrounding inflammation, were noted. Univariate and multivariate analyses evaluated the relationship between overall survival (OS) with demographic and clinical features.

RESULTS

Among 730 consecutive MF patients, tumors developed in 8.2% (n = 60), of whom 46.7% were diagnosed with advanced-stage MF from the beginning. The most common subtype was folliculotropic MF (53.3%). Most patients (55%) had multiple tumors, and the most frequent localization was the trunk (71.7%). Most tumors presented as smooth-surfaced, indurated papules and/or nodules (70%), while others were reddish-purple, occasionally accompanied by ulceration (50%), perilesional inflammation (23.3%), and attaining large dimensions (25%). Mortality was recorded in 51.7% of patients, and the 5-year OS rate from the diagnosis of tumors was 49%. Independent poor prognostic factors for OS in multivariate analysis included older age at the time of diagnosis, presence of tumors at the initial MF diagnosis, presence of over 20 tumors, and the existence of large tumors.

CONCLUSIONS

Tumoral MF seen in older patients, the first diagnosis of MF in this stage, presenting with generalized and large tumors, seems to be a predictive factor for OS.

Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

Skin of color in dermatopathology: does color matter?

Skin of color (SoC) remains an understudied and under taught area of dermatology despite its rising importance. Race and ethnicity play a particularly important role in dermatology as skin pigmentation can affect the manifestation and presentation of many common dermatoses. With this review, we seek to review pertinent differences in SoC histology, as well as highlight the histopathology of conditions more common in SoC and address inherent bias that may affect accurate dermatopathology sign out.

Primary cutaneous T-cell lymphoma: a review of the most common entities with focus on recent updates

Cutaneous T-cell lymphomas are an heterogeneous group of uncommon lymphoid neoplasms that are challenging to diagnose and require close collaboration between dermatologists, pathologists and hematologists/oncologists. This article reviews the most common cutaneous T-cell lymphomas: mycosis fungoides (both classic and variant forms) as well as its leukemic counterpart Sézary syndrome, CD30+ T-cell lymphoproliferative disorders including the ever-expanding group of lymphomatoid papulosis and primary cutaneous anaplastic large cell lymphoma, and primary cutaneous CD4+ small/medium lymphoproliferative disorder. We discuss the classic clinical and histopathologic features of these lymphomas and review how they can be distinguished from reactive entities. In particularly, updates to these diagnostic categories and current controversies in classification are highlighted. Moreover, we review the prognosis and treatment for each entity. These lymphomas exhibit variable prognosis, and therefore it is important to correctly classify atypical cutaneous T-cell infiltrates for appropriate patient treatment and prognosis. Cutaneous T-cell lymphomas are at the interface of several medical specialties; this review seeks to summarize key features of these lymphomas and highlight new and emerging insights into these lymphomas.

Hyperpigmented Mycosis Fungoides Masquerading as Longstanding Lichen Planus Pigmentosus: A Diagnostic Pitfall

BACKGROUND

Mycosis fungoides (MF) is a rare primary cutaneous T-cell lymphoma, accounting for 50%-60% of all cutaneous T-cell lymphoma cases. It has a prevalence of approximately 5-6 cases per 1 million people annually and a higher incidence in dark-skinned populations.

CASE PRESENTATION

We report a case of hyperpigmented MF in a 72-year-old dark-skinned man with a 5-year history of progressive, widespread poikilodermatous patches and thin plaques on the back and bilateral legs. The patient had been treated for lichen planus pigmentosus for 5 years without significant response to therapy.

ASSESSMENT

Multiple biopsies revealed a band-like lymphoid infiltrate in the dermis, accompanied by intraepidermal lymphocytes, some of which had larger hyperchromatic nuclei. CD4+ T lymphocytes were predominant over CD8+ T-positive cells located along the epidermis, dermoepidermal junction, and in the dermis.

DIAGNOSIS

A diagnosis of hyperpigmented MF was made based on the clinical, histopathological, and immunohistochemical findings.

CONCLUSION

This case report highlights the importance of considering hyperpigmented MF as a differential diagnosis in patients with longstanding lichen planus pigmentosus, particularly when there is a lack of response to therapy.

Mycosis fungoides and Sézary syndrome

Mycosis fungoides (MF) and Sézary syndrome (SS) are a distinct disease entity of cutaneous T-cell lymphoma with heterogenous clinical features and prognosis. MF mainly involves skin and usually shows an indolent and favorable clinical course. In patients with advanced-stage disease, extracutaneous involvement including lymph nodes, viscera, and blood, or large cell transformation may be observed. SS is a leukemic form of advanced-stage MF, characterized by generalized erythroderma. Early-stage MF can be treated with skin-directed therapy. However, patients with refractory or advanced-stage disease are associated with severe symptoms or poor prognosis, requiring systemic therapy. Recent progress in understanding the pathogenesis of MF/SS has contributed to advances in the management of these rare diseases. This review aims to describe the clinical manifestations, diagnosis, risk stratification, and treatment strategy of MF/SS, focusing on the recent updates in the management of these diseases.

Cutaneous lymphomas in African American/Black patients: pitfalls and presentations

This review describes and highlights differences in clinical presentations of cutaneous lymphomas (CLs), particularly in darker skin types, i.e., Skin of Color (SOC). We illustrate differences in clinical features on physical exam that can be a diagnostic challenge and suggest ways to recognize and identify these conditions at an early stage through a high level of suspicion. The review includes a summary of the epidemiology of various CLs, specifically highlighting the presentation and incidence in African American/Black patients, where the data are available. We also include a discussion of adult HTLV-1-associated T-cell leukemia/lymphoma (ATLL) which, although a systemic T-cell lymphoma, may present with skin manifestations and mimic MF, other CTCL subtypes, or other inflammatory dermatoses. Finally, this review highlights the possible use of imaging modalities, such as dermoscopy and reflectance-confocal microscopy, in diagnosing and recognizing cutaneous lymphomas in patients with darker skin types.

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

BACKGROUND

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

METHODS

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

RESULTS

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

CONCLUSIONS

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

Retrospective analysis of sepsis in cutaneous T-cell lymphoma reveals significantly greater risk in Black patients

BACKGROUND

Sepsis is a leading cause of morbidity, mortality, and resource utilization among patients with cutaneous T-cell lymphoma (CTCL).

OBJECTIVE

To characterize the demographic, clinical, and microbial attributes distinguishing patients with CTCL sepsis from other patients with non-Hodgkin lymphoma (NHL) sepsis and patients with CTCL in general.

METHODS

Two-part retrospective cohort study at an academic medical center from 2001-2019 involving patients with CTCL (n = 97) and non-CTCL NHL (n = 88) admitted with sepsis, and a same-institution CTCL patient database (n = 1094). Overall survival was estimated by Kaplan-Meier analyses.

RESULTS

Patients with CTCL sepsis were more likely to be older, Black, experience more sepsis episodes, die or be readmitted within 30 days of an inpatient sepsis episode, and develop Gram-positive bacteremia than patients with non-CTCL NHL sepsis. Staphylococcus aureus and Escherichia coli were the most frequently speciated organisms in CTCL (26%) and non-CTCL NHL (14%), respectively. No between-group differences were identified regarding sex, presence of central line, chemotherapy use, or disease stage. Compared with general patients with CTCL, patients with sepsis were Black and exhibited advanced-stage disease, higher body surface area involvement, and higher lactate dehydrogenase levels.

LIMITATIONS

Single institution, retrospective nature may limit generalizability.

CONCLUSION

Awareness of CTCL-specific risk factors is crucial for guiding sepsis prevention and improving patient outcomes.

Perspectives on and Quality of Life in Skin of Color Patients With Mycosis Fungoides/Sézary Syndrome: A Qualitative Analysis

Background Prior quantitative studies have described the diminished health-related quality of life (HRQoL) faced by the overall mycosis fungoides (MF)/Sézary syndrome (SS) population; yet, little is known about how the disease affects HRQoL in skin of color (SOC) patients. This qualitative study sought to explore the lived experiences of SOC patients with MF/SS and gain deeper insights into the impact the disease has on various facets of HRQoL.  Methodology Interviews with SOC patients with MF/SS ≥18 were recruited from a cutaneous lymphoma clinic. A thematic analysis was performed to identify overarching themes. Results Ten patients were invited to participate from July to September 2021. One patient with SS and seven patients with MF (four in the early stage and four in the advanced stage), with a median age of 60.5 years, agreed to participate. Emerging themes included diagnostic and therapeutic delays frequently due to initial misdiagnoses with other skin conditions. Physical and functional burdens significantly hindered participants' abilities to carry out daily responsibilities and maintain employment, and impacts on physical appearance (e.g., darkened skin) led to increased self-consciousness and lack of social acceptance. Participants regarded family and faith as main sources of support in addition to developing healthy coping strategies, such as self-acceptance and adaptability. All participants reported feeling satisfied with their access to healthcare information and the quality of care received. Conclusions Our findings provide greater insights into how HRQoL is impacted across SOC patients with MF/SS, which can help raise awareness among healthcare providers and assist with creating interdisciplinary healthcare approaches to better support the needs of this population.

Cutaneous T-cell lymphomas: 2023 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multidisciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or the blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Clinical Presentation and Outcome Differences Between Black Patients and Patients of Other Races and Ethnicities With Mycosis Fungoides and Sézary Syndrome

Importance

Mycosis fungoides and Sézary syndrome (MF/SS) has an increased incidence in Black patients, but clinical characteristics, treatments, and outcomes have been poorly characterized.

Objective

To assess racial differences in presentation and outcome and identify drivers for racial disparities in MF/SS.

Design, Setting, and Participants

A retrospective cohort analysis was conducted of 566 patients with MF/SS diagnosed from 1990 to 2020 and seen at the Winship Cancer Institute of Emory University and Grady Memorial Hospital, both in Atlanta, Georgia. Self-reported race and ethnicity were obtained from patient medical records and analyzed as 2 groups: non-Hispanic Black (Black) and all other races and ethnicities, including Asian, Hispanic, White, and unknown/undeclared (non-Black).

Main Outcomes and Measures

Univariate and multivariable models and Kaplan-Meier assessments were analyzed for overall survival and time to next treatment. The primary outcome was to assess differences in overall survival by racial and ethnic group. The hypotheses were formulated prior to data collection.

Results

Of the 566 patients with MF/SS identified (mean [SD] age 55 [16.4] years; 270 (47.7%) female), 257 were Black and 309 were non-Black. Black race was associated with increased rates of progression to a higher TNMB stage (39.8% in Black patients vs 29.1% in non-Black patients; P < .001) but not survival. Black patients were younger and had increased female predominance, higher TNMB stage, higher tumor stage, nodal involvement, and higher lactate dehydrogenase level compared with non-Black patients with MF/SS. Hypopigmented MF (HMF) was found in 62 patients, who were mostly Black (n = 59). Hypopigmented MF was significantly associated with survival on univariate and multivariable models, with 10-year survival of 100% in patients with HMF compared with 51.8% in patients without HMF. Black race was only associated with inferior outcomes after excluding patients with HMF who were younger than 60 years (hazard ratio [HR], 1.61; 95% CI, 1.02-2.55; P = .04), but not in patients older than 60 years (HR, 1.20; 95% CI, 0.80-1.81; P = .37). On multivariate analysis, among the cohort without HMF who were younger than 60 years, Black race remained statistically significant when controlling for cancer stage and large-cell transformation (HR, 1.27; 95% CI, 1.08-2.87; P = .43).

Conclusions and Relevance

In this cohort study, Black patients with MF/SS showed distinct clinical presentations and patterns of progression with heterogeneous outcomes depending on age at presentation and presence of HMF.

African American and Caucasian patients with Sézary syndrome have no differences in outcomes at an ethnically diverse urban medical center

Sézary syndrome (SS) is an aggressive cutaneous T-cell lymphoma with poor survival. We performed a retrospective review of SS patients at Emory University from 1990 to 2020. We collected data on race, clinical characteristics, therapy, and social determinants of health. Clinical endpoints were overall survival (OS) and time to next treatment (TTNT). Univariate association and multivariable analyses were assessed by Cox proportional hazards models. Among 62 patients, 45.2% were AA. The median OS and TTNT were 3.1 years and 6.3 months, respectively, with no difference by race. AA patients had a higher median baseline LDH (360 vs. 232, p = 0.002) and a longer delay in initiation of systemic therapy compared to CC patients (3.17 vs. 2.14 months, p = 0.039), but a shorter commute (<10 miles) and no difference in insurance coverage (p = 0.260). AA patients at an academic center had unique clinical features and treatment patterns, but similar survival to CC SS patients.

Skin Cancer in People of Color: A Systematic Review

BACKGROUND

People of African, Asian, Hispanic or Latino, Pacific Islander, and Native Indian descent are considered people of color by the Skin of Color Society (SOCS).

OBJECTIVES

In this study, we assess incidence, risk factors, clinical characteristics, histopathology, treatment, and survival for skin malignancies in people of color as defined by the SOCS, by systematically reviewing the literature.

METHODS

An electronic literature search of the PubMed, EMBASE, and MEDLINE databases was performed. Articles published from 1 January 1990 through 12 December 2020 were included in the search.

RESULTS

We identified 2666 publications potentially meeting the study criteria. Titles and abstracts of these studies were reviewed and 2353 were excluded. The full text of 313 articles were evaluated and 251 were included in this review.

CONCLUSION

Differences in incidence, patterns, treatment, and survival exist among people of color for cutaneous malignancies. Further research and initiatives are needed to account for and mitigate these differences.

Cutaneous T-cell lymphomas: 2021 update on diagnosis, risk-stratification, and management

DISEASE OVERVIEW

Cutaneous T-cell lymphomas are a heterogenous group of T-cell neoplasms involving the skin, the majority of which may be classified as Mycosis Fungoides (MF) or Sézary Syndrome (SS).

DIAGNOSIS

The diagnosis of MF or SS requires the integration of clinical and histopathologic data.

RISK-ADAPTED THERAPY

TNMB (tumor, node, metastasis, blood) staging remains the most important prognostic factor in MF/SS and forms the basis for a "risk-adapted," multi-disciplinary approach to treatment. For patients with disease limited to the skin, expectant management or skin-directed therapies is preferred, as both disease-specific and overall survival for these patients is favorable. In contrast, patients with advanced-stage disease with significant nodal, visceral or blood involvement are generally approached with systemic therapies, including biologic-response modifiers, histone deacetylase inhibitors, or antibody-based strategies, in an escalating fashion. In highly-selected patients, allogeneic stem-cell transplantation may be considered, as this may be curative in some patients.

Cutaneous T cell lymphoma

Primary cutaneous T cell lymphomas (CTCLs) are a heterogeneous group of lymphomas that present in the skin with no evidence of extracutaneous disease at the time of diagnosis. CTCL subtypes demonstrate a variety of clinical, histological, and molecular features, and can follow an indolent or a very aggressive course. The underlying pathogenetic mechanisms are not yet entirely understood. The pathophysiology of CTCL is complex and a single initiating factor has not yet been identified. Diagnosis is based on clinicopathological correlation and requires an interdisciplinary team. Treatment decision is made based on short-term and long-term goals. Therapy options comprise skin-directed therapies, such as topical steroids or phototherapy, and systemic therapies, such as monoclonal antibodies or chemotherapy. So far, the only curative treatment approach is allogeneic haematopoietic stem cell transplantation. Novel therapies, such as chimeric antigen receptor T cells, monoclonal antibodies or small molecules, are being investigated in clinical trials. Patients with CTCL have reduced quality of life and a lack of effective treatment options. Further research is needed to better identify the underlying mechanisms of CTCL development and course as well as to better tailor treatment strategies to individual patients.

Clinical characteristics and outcomes of black patients with mycosis fungoides and Sézary syndrome: a subgroup analysis of the phase III MAVORIC trial

Treatment-specific responses and comprehensive disease characteristics are limited in black patients with cutaneous T-cell lymphoma (CTCL). These shortcomings prompted us to perform a subgroup analysis of black patients enrolled in the MAVORIC trial - an international, randomized, phase 3 trial comparing mogamulizumab vs. vorinostat in relapsed/refractory mycosis fungoides (MF) and Sézary syndrome (SS). Ten percent (N = 37) of the entire MAVORIC population (N = 372) identified as black. Significant clinical differences in black patients when compared to non-black patients included a younger median age at enrollment (53 vs. 66 years; p < 0.001), an increased frequency of MF as opposed to SS (73% vs. 52.8%; p < 0.001), and higher rates of earlier-stage disease (IB-IIA) at enrollment (37.8% vs. 21.2%; p = 0.022). Mogamulizumab offered similar response rates and progression-free survival in black patients (7.57 months) compared to the entire MAVORIC population (7.7 months) and was associated with a similar safety profile.

Diagnosis and Management of Cutaneous Lymphomas Including Cutaneous T-cell Lymphoma

The cutaneous lymphomas are malignancies of T-cell and B-cell lymphocytes in which the skin is the primary organ of involvement. The cutaneous T-cell lymphomas include variants that can mimic the presentation of common skin diseases or arthropod bites. Mycosis fungoides, the most common cutaneous T-cell lymphoma, usually presents as fixed asymptomatic patches or plaques in sun-protected areas. The cutaneous B-cell lymphomas have fewer variants that often present as papules or nodules that can mimic nonmelanoma skin cancers. Some therapies for cutaneous lymphoma have unique side effects such as central hypothyroidism, hyperlipidemia, and peripheral neuropathy.

The impact of gender, age, race/ethnicity, and stage on quality of life in a spectrum of cutaneous lymphomas

PURPOSE

Cutaneous lymphomas (CLs) are a group of rare, potentially disfiguring and disabling cancers that can have a significant impact on quality of life (QoL). While previous studies have shown that mycosis fungoides (MF) and Sézary syndrome (SS) impair QoL, the effect of other types of CL on QoL has not been evaluated.

OBJECTIVE

To determine the impact of disease on QoL in all CL patients and to assess how QoL between the CL sub-types varies by demographic and clinical factors.

METHODS

The Cutaneous Lymphoma Distress Questionnaire (CL-DQ) was used to assess QoL. All CL patients seen in a multidisciplinary CL clinic were screened for eligibility. Questionnaire responses were collected over a 22-month period between 2017 and 2019. A cross-sectional analysis of CL-DQ scores from an initial visit was performed to determine the effect of disease on QoL across CL sub-types and the potential impact of patient demographics, CL sub-type, and type of treatment.

RESULTS

The study population consisted of 151 patients presenting with distinct types of cutaneous B- and T-cell lymphomas. Notable across the study population were the findings of frustration (44%), worry about progress/spread (43%), itching/pruritus (32%), and embarrassment/shame (28%). QoL was found to be most negatively affected in SS patients, females, younger patients, Black patients, and those with advanced stages of MF/SS.

CONCLUSIONS

Impairment of QoL due to CL correlates with gender, age, race/ethnicity, and stage of MF/SS. While the negative impact on QoL is most pronounced in SS patients, other CL sub-types also affect QoL and impact psychosocial distress. Our findings highlight the need for QoL assessment in all CL patients and further examination of disparities noted across demographic groups.

Epidemiology of Cutaneous T-Cell Lymphomas: A Systematic Review and Meta-Analysis of 16,953 Patients

Simple Summary

Cutaneous T-cell lymphomas (CTCL) are rare malignant diseases. In this study we have compared the cutaneous lymphoma registries of different countries, which included information on at least 100 patients. The frequencies of each CTCL subtype were compared within and between continents. We found that the registries differed importantly in terms of size and quality. Some rare CTCL subtypes, such as NK/T-cell lymphoma or subcutaneous panniculitis-like lymphomas, were more frequent in Asian countries, while others were evenly distributed. We discuss possible reasons for this and provide suggestions on how to build future CTCL registries.

Abstract

Cutaneous T-cell lymphomas (CTCL) are a heterogenous group of rare diseases. Many studies have reported on local epidemiology or geographic clustering, however we lack information from a global perspective. A systematic review and meta-analysis was conducted in Medline and the Cochrane Library based on a previously registered protocol and according to the preferred reporting of items for systematic reviews and meta-analyses (PRISMA). We selected publications that enrolled at least 100 patients with primary cutaneous lymphomas according to the current classifications. The relative frequencies (proportions) of subtypes were compared between studies and geographic regions in a meta-analysis. In total, 26 studies met our inclusion criteria, reporting on altogether 16,953 patients. Within primary cutaneous lymphomas, CTCL appeared to be 15% more frequent in Asian populations. Mycosis fungoides (MF) accounted for 62% of CTCL, with an important heterogeneity in frequencies between studies and continents. The proportion of Sézary syndrome (SS) was 3%, stable worldwide. Rare CTCL, such as NK/T-cell lymphoma or subcutaneous panniculitis-like lymphoma, were more frequent in Asian studies. This global meta-analysis of CTCL confirmed the predominance of CTCL among primary cutaneous lymphomas (83% on average) in the three analyzed continents, most of which were MF cases. It revealed the same proportions of SS across continents, and the heterogeneity of MF frequencies, suggesting the possible role of environmental factors in the pathophysiology of the latter. Registration number: CRD42020148295 (PROSPERO).

Hypopigmented Mycosis Fungoides: Loss of Pigmentation Reflects Antitumor Immune Response in Young Patients

Hypopigmented mycosis fungoides (HMF) is a form of cutaneous T-cell lymphoma (CTCL), a heterogeneous group of extranodal non-Hodgkin's lymphomas. HMF has a unique set of defining features that include light colored to achromic lesions, a predilection for darker skin phototypes, an early onset of disease, and predominance of CD8⁺ T-cells, among others. In the current review, we detail the known pathways of molecular pathogenesis for this lymphoma and posit that an active Th1/cytotoxic antitumor immune response in part explains why this variant is primarily seen in children/adolescents and young adults, who do not exhibit signs of immunosenescence. As a result of this potent cytotoxic response, HMF patients experience mostly favorable overall prognosis, while hypopigmentation may in fact represent a useful surrogate marker of cytotoxic immunity targeting the malignant cells. Understanding the molecular processes behind the specific features that define HMF may lead to improved diagnostic accuracy, personalized prognosis by risk stratification, and improved management of HMF. Moreover, improving our knowledge of HMF may aid our further understanding of other cutaneous lymphomas.