Medical history, lifestyle, family history, and occupational risk factors for mycosis fungoides and Sézary syndrome: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

Geospatial analyses demonstrate variation of cutaneous T-cell lymphomas across Australia, providing insights into possible causes

BACKGROUND

Cutaneous T-cell lymphomas (CTCLs) are rare with distinct diagnostic challenges. Equitable access to cancer care is a recognized priority, internationally. To date, the geospatial distribution of CTCL has not been definitively studied. Understanding the incidence and geographical distribution of patients with CTCL are critical first steps towards the ultimate goal of equity of care. Geospatial analyses also allow the opportunity to explore environmental causative factors: for CTCL, the contribution of solar ultraviolet (UV) radiation on causation remains unclear.

OBJECTIVES

We investigate geospatial patterns of CTCL incidence across Australia, compare with all rare cancers, and consider solar UV exposure on causality and diagnosis rates.

METHODS

All CTCL diagnoses (1 January 2000 to 31 December 2019) were obtained from the nationwide dataset. Areas of residence were collected according to nationally approved definitions. Bayesian spatial incidence models were applied. Geospatial distributions were visually analysed.

RESULTS

The CTCL age-standardised incidence rate was 7.7 (95% confidence interval 7.4-7.9) per million people per year in Australia. Diagnostic disparity was seen between Australian states/territories, with lower diagnosis rates in rural/remote and socioeconomically disadvantaged areas. Incidence exceeded the national average within more densely populated capital cities. Visual comparisons of the geospatial distribution of CTCL revealed marked discordances with the geospatial patterns of all rare cancers and solar UV in Australia.

CONCLUSIONS

Geographical heterogeneity in CTCL exists across Australia. Incidence reflects population density. Geospatial patterns of CTCL differ substantially from all rare cancers, with implications for the unique diagnostic challenges and unmet needs of this patient population. The distribution of CTCL across Australia does not support a causative link with UV exposure. Further global evaluation of geospatial patterns is warranted.

Update on T-Cell Lymphoma Epidemiology

PURPOSE OF REVIEW

T-cell lymphomas (TCLs) are a group of rare subtypes of non-Hodgkin lymphoma derived from mature T-lymphocytes. Recent updates in lymphoma classification based on the cell-of-origin pathogenesis have shed new light on TCL epidemiology and outcomes. Contemporary regional consortia and international studies, including those conducted recently in Asia and South America, have provided an updated delineation of the major subtypes across various global regions.

RECENT FINDINGS

Peripheral T-cell lymphoma, not otherwise specified (PTCL-NOS), remains the most common subtype globally except in Asia, where extra-nodal NK-T cell lymphoma (ENKTL) has emerged as the most prevalent. Angioimmunoblastic T-cell lymphoma (AITL) is the second most common subtype globally except in South America where its incidence falls behind adult T-cell leukemia/lymphoma (ATLL) and ENKTL. ALK-negative anaplastic large cell lymphoma (ALCL) has been recognized as the second most common subtype in some parts of South America. Studies on the newly classified breast implant-associated ALCL (BIA-ALCL) are beginning to reveal its distribution and risk factors. Deciphering the epidemiology of TCLs is a challenging endeavor due to the rarity of these entities and ongoing refinement in classification. Collaborative efforts on prospective registries based on the most current WHO classifications will help capture the true epidemiology of TCL subtypes to better focus resources for diagnostic, prognostic, and therapeutic efforts.

Sézary Syndrome in West Sweden: Exploring Epidemiology, Clinical Features, and Treatment Patterns in a Registry-Based Retrospective Analysis

Sézary syndrome (SS) is a rare primary cutaneous T-cell lymphoma variant. Despite various treatment options, it remains incurable, with a poor prognosis. There is an urgent need for additional descriptive research to enhance our understanding and treatment of SS. The aim of this retrospective register-based study was to outline patients' demographic characteristics; investigate the clinical, histopathological, and molecular findings; and assess treatment effectiveness with a focus on time to next treatment (TTNT) and disease progression. Data on 17 patients with SS were obtained from the primary cutaneous lymphoma register in West Sweden between 2012 and 2024. The results revealed that not all patients exhibited the classical triad of symptoms at diagnosis, emphasizing the need for personalized diagnostic approaches. The median survival was only 2.1 years, which reflects the aggressive nature of SS. The longest median TTNT was observed in triple therapy involving retinoids, interferon alpha, and extracorporeal photopheresis (ECP). There was no significant difference in TTNT between various lines of treatment. Early initiation of ECP treatment did not result in improved outcomes. This study highlights the importance of combination therapy for improved outcomes and underscores the need for future studies to identify optimal treatment approaches.

Clusters, crop dusters, and myth busters: a scoping review of environmental exposures and cutaneous T-cell lymphoma

INTRODUCTION

Cutaneous T-cell lymphoma (CTCL) is a heterogenous group of non-Hodgkin lymphomas. Similar presentation to benign conditions, significant genetic variation, and lack of definitive biomarkers contributes to diagnostic delay. The etiology of CTCL is unknown, and environmental exposures, such as geographic, occupational, chemicals, sunlight, and insects have been investigated.

EVIDENCE ACQUISITION

Review of the literature for CTCL and exposures was performed in PubMed and Google Scholar in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-analyses (PRISMA) Extension for Scoping Reviews. This search yielded 193 total results, which were initially screened with defined inclusion and exclusion criteria. The 45 remaining articles were reviewed and classified by exposure type.

EVIDENCE SYNTHESIS

The most frequently investigated CTCL exposure type was geographic (13/45 articles, 29%). Chemical exposures were commonly discussed (10/45 articles, 22%), along with occupational (10/45 articles, 22%). Insect exposures (6/45, 13%) and sun exposure (3/45, 7%) were also reviewed, along with articles describing multiple exposure types (3/45, 7%). Article types ranged from cases to systematic reviews and case-control studies. Evidence linking CTCL and these exposures was mixed. Limitations of this investigation include reliance on patient reporting and frequent speculation on disease association versus causality.

CONCLUSIONS

This investigation synthesizes the current literature on exposures potentially implicated in the pathogenesis of CTCL, while offering guidance on patient history-taking to ensure potential exposures are captured. Awareness of these possible associations may improve understanding of disease pathogenesis and diagnosis. Moreover, these insights may help with public health decision-making and disease mitigation.

Evaluation of Oxidative Stress by Thiol/Disulphide Homeostasis in Patients with Mycosis Fungoides: A Prospective Double-Centre Study

Background

Mycosis fungoides (MF) is the most common cutaneous T-cell lymphoma with unknown etiopathogenesis. Oxidant and antioxidant balance is important for cell function and normal metabolism. An imbalance between pro-oxidants and antioxidants causes oxidative stress. A recent focus has been on thiol/disulphide homeostasis as a novel marker of oxidative stress.

Aims and Objectives

This study aimed to evaluate the role of oxidative stress in MF by analysing thiol/disulphide homeostasis.

Materials and Methods

A total of 103 patients (48 female, 55 male) and a control group of 120 healthy individuals (48 female, 72 male) from two tertiary care hospitals were included in our study. Serum native thiol, total thiol and disulphide levels were evaluated using novel method developed by Erel and Neeliolu.

Results

Native thiol levels were 340.30 ± 87.44 in the patient group and 401.62 ± 69.45 in the control group. Total thiol value was 374.17 ± 87.78 in the patient group and 428.54 ± 70.05 in the control group. Native thiol and total thiol levels were significantly lower in the patient group compared to the control group (P < 0.001 and P < 0.001). The disulphide value was 16.93 ± 6.46 in the patient group and 13.46 ± 5.06 in the control group. Disulphide levels were found to be significantly higher in the patient group compared to the control group (P < 0.001).

Conclusions

In our study, thiol/disulphide balance shifted towards disulphide which indicates the presence of oxidative stress especially in the early stage while 93.2% of our patients had early-stage MF. We think that this may have pathogenetic and prognostic significance.

Endolysin Inhibits Skin Colonization by Patient-Derived Staphylococcus Aureus and Malignant T-Cell Activation in Cutaneous T-Cell Lymphoma

Staphylococcus aureus is suspected to fuel disease activity in cutaneous T-cell lymphomas. In this study, we investigate the effect of a recombinant, antibacterial protein, endolysin (XZ.700), on S. aureus skin colonization and malignant T-cell activation. We show that endolysin strongly inhibits the proliferation of S. aureus isolated from cutaneous T-cell lymphoma skin and significantly decreases S. aureus bacterial cell counts in a dose-dependent manner. Likewise, ex vivo colonization of both healthy and lesional skin by S. aureus is profoundly inhibited by endolysin. Moreover, endolysin inhibits the patient-derived S. aureus induction of IFNγ and the IFNγ-inducible chemokine CXCL10 in healthy skin. Whereas patient-derived S. aureus stimulates activation and proliferation of malignant T cells in vitro through an indirect mechanism involving nonmalignant T cells, endolysin strongly inhibits the effects of S. aureus on activation (reduced CD25 and signal transducer and activator of transcription 5 phosphorylation) and proliferation (reduced Ki-67) of malignant T cells and cell lines in the presence of nonmalignant T cells. Taken together, we provide evidence that endolysin XZ.700 inhibits skin colonization, chemokine expression, and proliferation of pathogenic S. aureus and blocks their potential tumor-promoting effects on malignant T cells.

Chronic Obstructive Pulmonary Disease and Risk of Cutaneous T-cell Lymphoma: A Danish Population-based Cohort Study

Abstract is missing (Short communication)

Role of Neutrophil-to-Lymphocyte Ratio (NLR) in Patients with Mycosis Fungoides

BACKGROUND

The neutrophil/lymphocyte ratio (NLR) at baseline has been demonstrated to correlate with higher stages of disease and to be a prognostic factor in numerous cancers. However, its function as a prognostic factor for mycosis fungoides (MF) has not been yet clarified.

OBJECTIVE

Our work aimed to assess the association of the NLR with different stages of MF and to outline whether higher values of this marker are related to a more aggressive MF.

METHODS

We retrospectively calculated the NLRs in 302 MF patients at the moment of diagnosis. The NLR was obtained using the complete blood count values.

RESULTS

The median NLR among patients with early stage disease (low-grade IA-IB-IIA) was 1.88, while the median NLR for patients with high-grade MF (IIB-IIIA-IIIB) was 2.64. Statistical analysis showed positive associations of advanced MF stages with NLRs higher than 2.3.

CONCLUSIONS

Our analysis demonstrates that the NLR represents a cheap and easily available parameter functioning as a marker for advanced MF. This might guide physicians in recognizing patients with advanced stages of disease requiring a strict follow-up or an early treatment.

Occupational Exposures and Risks of Non-Hodgkin Lymphoma: A Meta-Analysis

Non-Hodgkin lymphoma (NHL) is a heterogeneous group with different types of diseases. It remains unclear as to what has led to an increase in incidences of NHL, however, chemical substance exposure is known to be one of the risk factors for the disease. Therefore, we performed a systematic review and meta-analysis including case-control, cohort, and cross-sectional observational epidemiological studies to verify the association between occupational exposure to carcinogens and NHL risk. Articles between the years 2000 and 2020 were collected. Two different reviewers performed a blind selection of the studies using the Rayyan QCRI web app. Post-completion, the selected articles were extracted and analyzed via the RedCap platform. Our review resulted in 2719 articles, of which 51 were included in the meta-analysis, resulting in an overall OR of 1.27 (95% CI 1.04-1.55). Furthermore, it was observed that the main occupation associated with the increased risk of NHL was that in which workers are exposed to pesticides. We therefore conclude that the evidence synthesis of the epidemiological literature supports an increased risk for NHL, regardless of subtype, considering occupational exposure to certain chemical compounds, mainly pesticides, benzene, and trichlorethylene, and certain classes of work, primarily in the field of agriculture.

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

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

Characteristics and Outcomes for Hospitalized Patients With Cutaneous T-Cell Lymphoma

Importance

Cutaneous T-cell lymphoma (CTCL) is a group of rare, complex cutaneous malignant neoplasms associated with significant disease burden on patients and the health care system. Currently, the population of patients with CTCL admitted to the hospital remains largely uncharacterized and poorly understood.

Objective

To characterize the clinical characteristics, course of hospitalization, and mortality outcomes of an inpatient CTCL cohort.

Design, Setting, and Participants

This multicenter retrospective cohort study reviewed medical records for adult patients (age ≥18 years) with a CTCL diagnosis per National Comprehensive Cancer Network guidelines admitted for inpatient hospitalization at 5 US academic medical centers with inpatient dermatology consult services and CTCL clinics between August 2016 and August 2020.

Main Outcomes and Measures

Patient demographics, clinical history and findings, hospitalization courses, and mortality outcomes.

Results

A total of 79 hospitalized patients with CTCL were identified, including 52 (70.3%) men and 22 (29.7%) women, with a median (IQR) age at hospitalization of 62.9 (27-92) years. The majority of admitted patients with CTCL were White (65 patients [82.3%]), had disease classified as mycosis fungoides (48 patients [61.5%]), and had advanced-stage disease (≥IIB, 70 patients [89.7%]). Most hospitalizations were complicated by infection (45 patients [57.0%]) and required intravenous antibiotic therapy (45 patients [57.0%]). In-hospital mortality occurred in 6 patients (7.6%) and was associated with higher body mass index (36.5 vs 25.3), history of thromboembolic disease (50.0% vs 12.3%), and diagnosis of sepsis on admission (66.7% vs 20.5%). At 1-year postdischarge, 36 patients (49.3%) patients had died, and mortality was associated with history of solid organ cancers (27.8% vs 10.8%), wound care as the reason for dermatology consultation (58.3% vs 24.3%), and presence of large cell transformation (58.3% vs 22.9%).

Conclusions and Relevance

The findings of this cohort study improve the understanding of hospitalized patients with CTCL and lend valuable insight into identifying factors associated with both in-hospital and long-term mortality outcomes. This refined understanding of the inpatient CTCL population provides a foundation for larger, more robust studies to identify causal risk factors associated with mortality, development of prognostic scoring systems to estimate the probability of hospital mortality. Overall, the findings may prompt physicians caring for patients with CTCL to implement preventive strategies to diminish hospitalization and improve clinical management across this unique disease spectrum.

Etiology of non-Hodgkin lymphoma: A review from epidemiologic studies

Non-Hodgkin lymphoma (NHL) contributes to significant cancer burden and mortality globally. In recent years, much insight into the causes of NHL has been gained by evaluating global differences through international collaboration and data pooling. NHL comprises different subtypes that are known to behave differently, exhibit different prognoses, and start in distinct cell types (B-cell, T-cell, and NK-cell, predominantly), and there is increasing evidence that NHL subtypes have different etiologies. Classification of NHL can be complex, with varying subtype frequencies, and is a consideration when evaluating geographic differences. Because of this, international pooling of well-executed epidemiologic studies has conferred power to evaluate NHL by subtype and confidence with minimal misclassification. Given the decreasing burden in some regions while cases rise in Asia, and especially China, this report focuses on a review of the established etiology of NHL from the epidemiologic literature in recent decades, highlighting work from China. Topics covered include demographic patterns and genetic determinants including family history of NHL, as well as infection and immunosuppression, lifestyle, environment, and certain occupational exposures contributing to increased disease risk.

Staphylococcus aureus Induces Signal Transducer and Activator of Transcription 5‒Dependent miR-155 Expression in Cutaneous T-Cell Lymphoma

Staphylococcal enterotoxins are believed to fuel disease activity in cutaneous T-cell lymphoma. Recent data support this by showing that antibiotics inhibit malignant T cells in skin lesions in mycosis fungoides and Sézary syndrome, the most common forms of cutaneous T-cell lymphoma. Yet, it remains incompletely characterized how staphylococcal enterotoxins fuel disease activity. In this study, we show that staphylococcal enterotoxins induce the expression of the oncogenic microRNA miR-155 in primary malignant T cells. Thus, staphylococcal enterotoxins and Staphyloccocus aureus isolates from lesional skin of patients induce miR-155 expression at least partly through the IL-2Rg‒Jak‒signal transducer and activator of transcription 5 pathway, and the effect is augmented by the presence of nonmalignant T cells. Importantly, mycosis fungoides lesions harbor S. aureus, express Y-phosphorylated signal transducer and activator of transcription 5, and display enhanced miR-155 expression, when compared with nonlesional and healthy skin. Preliminary data show that aggressive antibiotic therapy is associated with decreased Y-phosphorylated signal transducer and activator of transcription 5 and miR-155 expression in lesional skin in two patients with Sézary syndrome. In conclusion, we show that S. aureus and its enterotoxins induce enhanced expression of oncogenic miR-155, providing mechanistic insight into the role of S. aureus in cutaneous T-cell lymphoma. Our findings support that environmental stimuli such as bacteria can fuel disease progression in cutaneous T-cell lymphoma.

Epidemiology of Non-Hodgkin's Lymphoma

Non-Hodgins’s lymphoma (NHL) is the most common hematological malignancy worldwide, accounting for nearly 3% of cancer diagnoses and deaths. NHL is the seventh most prevalent cancer and has the sixth highest mortality among cancers in the US. NHL accounts for 4% of US cancer diagnoses, and incidence has increased 168% since 1975 (while survival has improved 158%). NHL is more common among men, those >65 years old, and those with autoimmune disease or a family history of hematological malignancies. NHL is a heterogenous disease, with each subtype associated with different risk factors. Marginal zone lymphoma (MZL) is strongly associated with Sjogren’s syndrome (SS) and Hashimoto’s thyroiditis, while peripheral T-cell lymphoma (PTCL) is most associated with celiac disease. Occupational exposures among farm workers or painters increases the risk of most of the common subtypes. Prior radiation treatment, obesity, and smoking are most highly associated with diffuse large B-cell lymphoma (DLBCL), while breast implants have been rarely associated with anaplastic large cell lymphoma (ALCL). Infection with Epstein–Barr Virus (EBV) is strongly associated with endemic Burkitts lymphoma. HIV and human herpes virus 8 (HHV-8), is predisposed to several subtypes of DLBCL, and human T-cell lymphoma virus (HTLV-1) is a causative agent of T-cell lymphomas. Obesity and vitamin D deficiency worsen NHL survival. Atopic diseases and alcohol consumption seem to be protective against NHL.

Mycosis Fungoides and Its Relationship to Atopy, Serum Total IgE, and Eosinophil Counts

INTRODUCTION

A recent serologic study and reports of increased serum total IgE (IgE-t) and eosinophil counts have suggested that the prevalence of atopy is more common in patients with mycosis fungoides (MF) than previously recognized.

PATIENTS AND METHODS

Patients with clinicopathologic features that were diagnostic and/or consistent with MF and/or the presence or absence of an atopic disorder (eg, allergic rhinitis, asthma, eczematous dermatitis), which was determined by patient history, eosinophil counts, and serum IgE-t obtained at evaluation, were selected from a patient registry. The MF population was divided into those with atypical and typical clinical presentations. We performed matching of controls using age, sex, and race from the 2005 to 2006 National Health Education Survey.

RESULTS

A history of allergic rhinitis was recorded for 186 of 728 patients (25.5%) with typical MF and 71 of 229 patients (31%) with atypical MF. However, the prevalence of asthma and eczema was low. The IgE-t and eosinophil counts were higher for patients with typical MF than for controls and for patients with atopic diathesis than for patients without atopy. The IgE-t and eosinophil counts were higher for the patients with advanced-stage MF compared with those for the patients with less-advanced disease for both atopic and nonatopic cohorts. In the Cox model with age and clinical stage as covariates, a history of atopy, increased IgE-t, and blood eosinophilia (> 500 cells/mm3) did not correlate with overall survival.

CONCLUSION

The findings from the present study did not reveal a significant association of atopy in patients with MF. However, atopy is a factor in the increased IgE-t and eosinophil counts observed in MF. Another factor is related to the disease stage, including possibly the influence of cytokines secreted by T-helper type 2-polarized neoplastic cells.

The relationship between physical activity and lymphoma: a systematic review and meta analysis

Background

The literature suggests an increased risk between anthropometrics including higher body mass index and lymphoma incidence; however, the association with physical activity remains unclear. A systematic review/meta-analysis was therefore performed to examine this association with physical activity (total, recreational or occupational).

Methods

PubMed, Web of Science and Embase were reviewed from inception to October 2019 identifying relevant observational studies. Non-Hodgkin lymphoma (NHL) including subtypes diffuse large B cell lymphoma, follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, and Hodgkin lymphoma (HL) were analyzed. Included studies reported activity, lymphoma cases, effect size and variability measures, and were restricted to human subjects of any age. Data was pooled generating summary relative risk (RR) estimates with 95% confidence intervals (CI) using random-effects models with primary outcome of histologically confirmed incident lymphoma.

Results

One thousand four hundred studies were initially identified with 18 studies (nine cohort, nine case-control) included in final analysis. Comparing highest vs. lowest activity categories was protective for all lymphoma (RR 0.89, 95%CI 0.81–0.98). Sensitivity analysis demonstrated effect persistence within case-control studies (RR 0.82, 95% CI 0.71–0.96), but not cohort studies (RR 0.95, 95%CI 0.84–1.07). Borderline protective effect was seen for NHL (RR 0.92, 95%CI 0.84–1.00), but not HL (RR 0.72, 95%CI 0.50–1.04). Analysis by NHL subtype or gender showed no effect. Dose response analysis demonstrated a protective effect (p = 0.034) with a 1% risk reduction per 3 MET hours/week (RR 0.99, 95%CI 0.98–1.00).

Conclusions

Physical activity may have a protective effect against lymphoma development; further studies are required to generate recommendations regarding health policy.

Trial registration

This study was registered prospectively at PROSPERO: CRD42020156242.

Early-stage Mycosis Fungoides: Epidemiology and Prognosis

Most patients with mycosis fungoides are diagnosed with early-stage disease. However, prevalence of early-stage disease is unknown, and evidence of its burden is scarce. The aim of this study is to estimate the prevalence of early-stage mycosis fungoides, how long patients live with early-stage disease and to characterise these patients. Data were obtained from 4 key publications and from US cancer registries (Surveillance, Epidemiology and End Results Program; SEER). The derived incidence of early-stage mycosis fungoides was 0.26/100,000 (UK), 0.29/100,000 (US) and 0.38/100,000 (US-SEER) and the prevalence was 4.8/100,000 (UK), 5.2/100,000 (US) and 6.6/100,000 (US-SEER). Early-stage disease may last for 18 years. From SEER registries, 3,132 were diagnosed at early stage (mostly stage IA). Median age at diagnosis was 58 years. Compared with stage IA, the relative risk of death was 1.3 for stage IB and 3.5 for stage IIA. We confirm the rarity of early-stage mycosis fungoides, a differential prognosis and the potential for elevated burden of disease.

Prevalence of atopy and staphylococcal superantigen-specific immunoglobulin E (IgE) antibodies and total serum IgE in primary cutaneous T- and B-cell lymphoma

The prevalence of atopy was investigated in 20 patients with Sézary syndrome (SS), 20 patients with plaque phase mycosis fungoides (MF), 9 patients with primary cutaneous marginal zone lymphoma (pcMZL) and 8 patients with primary cutaneous follicle center lymphoma (pcFCL) with the Phadiatop multi-allergen test. The relationship among serologic atopy, IgE reactivity against Staphyloccocal enterotoxin superantigens, and serum total IgE (IgE-t) levels and their prognostic implications in SS was investigated. Phadiatop test was positive in 45%, 15%, 33% and 0% of samples of SS, MF, pcMZL and pcFCL, respectively. IgE-t levels were also increased in SS, pcMZL and marginally MF. No correlation was found with patients' history of atopic disorders. Staphylococcal superantigen-specific IgE ≥ 0.35 kUa/L, most often against toxic shock syndrome toxin-1, was detected in 40% of Sézary samples followed by MF (20%). In the absence of serologic atopy (negative Phadiatop test), IgE-t levels for patients with SS and MF were not significantly higher than controls whereas the levels for pcMZL remained high. Furthermore, even with a negative Phadiatop test, IgE-t values were higher in sera of patients with SSAg-IgE ≥ 0.35 kUa/L vis-à-vis < 0.35 kUa/L across all diagnostic categories including controls albeit the difference was statistically significant only for SS. The presence of specific IgE antibodies ≥ 0.35 kUa/L, IgE-t > 122 kU/L or eosinophils > 500/µL had no impact on survival of patients with SS. These results indicate that a pathogenic link may exist between an atopic diathesis and development of SS and possibly pcMZL.

Epidemiology and Pathology of T- and NK-Cell Lymphomas

PURPOSE

This review will describe and update readers on the recent changes in the 2017 WHO classification regarding peripheral T-cell lymphomas.

RECENT FINDINGS

Signficant advances in molecular studies have resulted in revisions to the classification as well as introduction to provisional entities such as breast implant-associated ALCL and nodal PTCL with T-follicular helper phenotype.

SUMMARY

Major advances in molecular and gene expression profiling has expanded our knowledge of these rare and aggressive diseases.

Major Comorbidities of Atopic Dermatitis: Beyond Allergic Disorders

The consequences of atopic dermatitis reach beyond the skin and past childhood. Patients with atopic dermatitis are at risk of developing allergic comorbidities, but less is known about the associations between atopic dermatitis and non-allergic conditions. Understanding these non-allergic comorbidities has the potential to improve patient outcomes and to help mitigate the cost and burdens associated with these conditions. Atopic dermatitis is associated with cutaneous bacterial infections, more severe forms/courses of cutaneous viral infections, and extra-cutaneous infections. Atopic dermatitis is also associated with several mental health comorbidities particularly attention-deficit hyperactivity disorder, anxiety, and depression. Data are largely inconsistent for specific cancers, but atopic dermatitis appears to protect against malignancy overall; severe long-term atopic dermatitis is associated with adult lymphomas. Atopic dermatitis may also be associated with obesity, cardiovascular disease, and autoimmune disease, particularly alopecia areata and gastrointestinal immune-mediated disorders. Although the causative mechanisms underlying these associations are poorly understood, treating physicians should be aware of associations in seeking to alleviate the burden for patients with atopic dermatitis.

T-cell Lymphoma Epidemiology: the Known and Unknown

T-cell lymphoma, a collection of subtypes of Non-Hodgkin lymphoma, is a rare malignancy. The low prevalence of this disease has made it challenging to identify subtype-specific risk factors. Potential risk factors could enable us to identify high-risk patients and predict patient outcomes. Here, we report on the current epidemiologic and prognostic factors data associated with the individual subtypes both of peripheral T-cell lymphoma (PTCL) and cutaneous T-cell lymphoma (CTCL) found in large cohort and case studies. Additionally, with recent findings, as well as updates in the new World Health Organization (WHO) classification of lymphoid neoplasms, we consider what this could do to change our approach to this group of diseases.

Occupational mycosis fungoides - a case series

BACKGROUND

Mycosis fungoides (MF) is the most frequent type of cutaneous T-cell lymphoma. MF has long been considered to develop as the result of a combination of genetic defects and exogenous triggers. Although no specific MF-associated environmental trigger has been established to date, some studies have suggested that occupational exposures may occasionally trigger the onset of MF.

OBJECTIVE

In this observational study, we aimed at underscoring the potential association between occupational exposure and MF.

METHODS

We ascertained a cohort of 150 MF patients for possible occupational exposure.

RESULTS

Five MF patients with occupational exposure were identified in our cohort. Three patients had intensive contact with aromatic hydrocarbons; two of them were working in the same plant and in the same unit for more than 30 years. The third patient had been in contact with aromatic hydrocarbons for a total of 8 years. Patient 4 had additional contact for 12 years with hydrazine, and patient 5 had been exposed for 3 years to formaldehyde.

CONCLUSION

The clustering of two cases of MF, an exceptionally rare disease, in the same plant unit, as well as the long-term, intense occupational exposure in other cases, substantiates the notion that occupational exposures may contribute to the pathogenesis of MF.

2016 US lymphoid malignancy statistics by World Health Organization subtypes

Collectively, lymphoid neoplasms are the fourth most common cancer and the sixth leading cause of cancer death in the United States. The authors provide contemporary lymphoid neoplasm statistics by subtype based on the 2008 World Health Organization classifications, including the most current US incidence and survival data. Presented for the first time are estimates of the total numbers of US lymphoid neoplasm cases by subtype as well as a detailed evaluation of incidence and survival statistics. In 2016, 136,960 new lymphoid neoplasms are expected. Overall lymphoma incidence rates have declined in recent years, but trends vary by subtype. Precursor lymphoid neoplasm incidence rates increased from 2001 to 2012, particularly for B-cell neoplasms. Among the mature lymphoid neoplasms, the fastest increase was for plasma cell neoplasms. Rates also increased for mantle cell lymphoma (males), marginal zone lymphoma, hairy cell leukemia, and mycosis fungoides. Like incidence, survival for both mature T-cell lymphomas and mature B-cell lymphomas varied by subtype and by race. Patients with peripheral T-cell lymphomas had among the worst 5-year relative survival (36%-56%, depending on race/sex), while those with mycosis fungoides had among the best survival (79%-92%). For B-cell lymphomas, 5-year survival ranged from 83% to 91% for patients with marginal zone lymphoma and from 78% to 92% for those with hairy cell leukemia; but the rates were as low as 47% to 63% for patients with Burkitt lymphoma and 44% to 48% for those with plasma cell neoplasms. In general, black men had the lowest survival across lymphoid malignancy subtypes. These contemporary incidence and survival statistics are useful for developing management strategies for these cancers and can offer clues regarding their etiology. CA Cancer J Clin 2016;66:443-459. © 2016 American Cancer Society.

Comprehensive Evaluation of Medical Conditions Associated with Risk of Non-Hodgkin Lymphoma using Medicare Claims ("MedWAS")

BACKGROUND

Certain medical conditions affect risk of non-Hodgkin lymphoma (NHL), but the full range of associations is unknown. We implemented a novel method ("medical condition-wide association study," MedWAS) to comprehensively evaluate medical risk factors for NHL documented in administrative health claims.

METHODS

Using Surveillance, Epidemiology, and End Results (SEER)-Medicare data, we conducted a case-control study comparing NHL cases [N = 52,691, age 66+ years, with five subtypes: chronic lymphocytic leukemia/small lymphocytic lymphoma, diffuse large B-cell lymphoma (DLBCL), follicular lymphoma, marginal zone lymphoma (MZL), T-cell lymphoma (TCL)] to controls (N = 200,000). We systematically screened for associations with 5,926 medical conditions documented in Medicare claims more than 1 year before selection.

RESULTS

Fifty-five conditions were variously associated with NHL. Examples include well-established associations of human immunodeficiency virus, solid organ transplantation, and hepatitis C virus with increased DLBCL risk (ORs 3.83, 4.27, and 1.74, respectively), and autoimmune conditions with DLBCL and MZL (e.g., ORs of 2.10 and 4.74, respectively, for Sjögren syndrome). Risks for all NHL subtypes were increased after diagnoses of nonmelanoma skin cancer (ORs 1.19-1.55), actinic keratosis (1.12-1.25), or hemolytic anemia (1.64-4.07). Nine additional skin conditions increased only TCL risk (ORs 2.20-4.12). Diabetes mellitus was associated with increased DLBCL risk (OR 1.09). Associations varied significantly across NHL subtypes for 49 conditions (89%).

CONCLUSION

Using an exploratory method, we found numerous medical conditions associated with NHL risk, and many associations varied across NHL subtypes.

IMPACT

These results point to etiologic heterogeneity among NHL subtypes. MedWAS is a new method for assessing the etiology of cancer and other diseases. Cancer Epidemiol Biomarkers Prev; 25(7); 1105-13. ©2016 AACR.

Adolescent weight and height are predictors of specific non-Hodgkin lymphoma subtypes among a cohort of 2,352,988 individuals aged 16 to 19 years

BACKGROUND

The age-adjusted annual incidence of non-Hodgkin lymphoma (NHL) has risen worldwide. This trend may be affected by the secular increase in height and the sharp upswing in adolescent overweight; these drive increased insulinlike growth factor 1 and chronic inflammation, which may play an etiologic role. This study examined the association of the body mass index (BMI) and height of adolescents with NHL subtypes, which have been insufficiently evaluated.

METHODS

Health-related data on 2,352,988 Israeli adolescents, aged 16 to 19 years, who were examined between 1967 and 2011 were linked to the Israel National Cancer Registry to derive the NHL incidence up to December 31, 2012 (4021 cases). Cox proportional hazards modeling was used to estimate the multivariate-adjusted hazard ratio (HR) for NHL subtypes associated with the BMI and height of adolescents.

RESULTS

Adolescent overweight and obesity were associated with an HR of 1.25 (95% confidence interval [CI], 1.13-1.37; P = 1.14 × 10(-5) ) for NHL in comparison with normal weight. There was a graded association of height with NHL (P = 4.29 × 10(-9) ), with the tallest adolescents (≥ 95th percentile vs 25th to < 50th percentiles [US Centers for Disease Control and Prevention]) exhibiting an HR of 1.28 (95% CI, 1.04-1.56). Marginal zone lymphoma, primary cutaneous lymphoma (PCL), and diffuse large B-cell lymphoma (DLBCL) showed the strongest associations for overweight/obesity, and DLBCL and PCL showed the strongest associations for height.

CONCLUSIONS

The findings of this large cohort study add to the growing body of evidence showing that higher body weight and taller stature during adolescence are associated with an increased risk of NHL and may modestly contribute to its increasing incidence. Further studies are needed to elucidate the mechanisms linking anthropometric measures and NHL risk.

Staphylococcal enterotoxin A (SEA) stimulates STAT3 activation and IL-17 expression in cutaneous T-cell lymphoma

Cutaneous T-cell lymphoma (CTCL) is characterized by proliferation of malignant T cells in a chronic inflammatory environment. With disease progression, bacteria colonize the compromised skin barrier and half of CTCL patients die of infection rather than from direct organ involvement by the malignancy. Clinical data indicate that bacteria play a direct role in disease progression, but little is known about the mechanisms involved. Here, we demonstrate that bacterial isolates containing staphylococcal enterotoxin A (SEA) from the affected skin of CTCL patients, as well as recombinant SEA, stimulate activation of signal transducer and activator of transcription 3 (STAT3) and upregulation of interleukin (IL)-17 in immortalized and primary patient-derived malignant and nonmalignant T cells. Importantly, SEA induces STAT3 activation and IL-17 expression in malignant T cells when cocultured with nonmalignant T cells, indicating an indirect mode of action. In accordance, malignant T cells expressing an SEA-nonresponsive T-cell receptor variable region β chain are nonresponsive to SEA in monoculture but display strong STAT3 activation and IL-17 expression in cocultures with SEA-responsive nonmalignant T cells. The response is induced via IL-2 receptor common γ chain cytokines and a Janus kinase 3 (JAK3)-dependent pathway in malignant T cells, and blocked by tofacitinib, a clinical-grade JAK3 inhibitor. In conclusion, we demonstrate that SEA induces cell cross talk-dependent activation of STAT3 and expression of IL-17 in malignant T cells, suggesting a mechanism whereby SEA-producing bacteria promote activation of an established oncogenic pathway previously implicated in carcinogenesis.

Primary cutaneous lymphomas: diagnosis and treatment

Primary cutaneous lymphomas (CLs) are a heterogeneous group of lymphoproliferative neoplasms, with lymphatic proliferation limited to the skin with no involvement of lymph nodes, bone marrow or viscera at the diagnosis. Cutaneous lymphomas originate from mature T-lymphocytes (65% of all cases), mature B-lymphocytes (25%) or NK cells. Histopathological evaluation including immunophenotyping of the skin biopsy specimen is the basis of the diagnosis, which must be complemented with a precise staging of the disease and identification of prognostic factors, to allow for the choice of the best treatment method as well as for the evaluation of the treatment results.

To Each Its Own: Linking the Biology and Epidemiology of NHL Subtypes

Non-Hodgkin lymphoma (NHL) constitutes a diverse group of more than 40 subtypes, each characterized by distinct biologic and clinical features. Until recently, pinpointing genetic and epidemiologic risk factors for individual subtypes has been limited by the relative rarity of each. However, several large pooled case-control studies have provided sufficient statistical power for detecting etiologic differences and commonalities between subtypes and thus yield new insight into their unique epidemiologic backgrounds. Here, we review the subtype-specific medical, lifestyle, and biologic components identified in these studies, which suggest that a complex interplay between host genetics, autoimmune disorders, modifiable risk factors, and occupation contributes to lymphomagenesis.

New insights into the epidemiology of non-Hodgkin lymphoma and implications for therapy

Non-Hodgkin lymphoma (NHL) comprises numerous biologically and clinically heterogeneous subtypes, with limited data examining the risk factors for these distinct disease entities. Many limitations exist when studying lymphoma epidemiology; therefore, until recently, little was known regarding the etiology of NHL subtypes. This review highlights the results of recent pooled analyses examining the risk factors for NHL subtypes. We outline the heterogeneity and commonality among the risk factors for NHL subtypes, with proposed subtype-specific as well as shared etiologic mechanisms. In addition, we describe how the study of lymphoma epidemiology may translate into prevention or therapeutic targeting as we continue to explore the complexities of lifestyle and genetic factors that impact lymphomagenesis.

Epidemiology and etiology of non-hodgkin lymphoma

Non-Hodgkin lymphoma (NHL) consists of many histologically and biologically distinct lymphoid malignancies with poorly understood, but possibly distinct, etiologies. The patterns of incidence and time trend vary not only by age, sex, and race/ethnicity in the USA, but also show significant geographic differences, suggesting the potential role of infectious agents, environmental factors, and lifestyle factors in addition to host genetic status in the development of NHL. Important pathogenetic mechanisms include immune modulation and chronic antigen stimulation. Epidemiologic studies in the past two decades have provided intriguing new insights on the possible causes of lymphoma and support the idea that there is some mechanistic commonality of lymphomagenesis, but significant etiologic heterogeneity clearly exists. This review presents a summary of the current understanding of the descriptive epidemiology and etiology of NHL and suggests areas of focus for future epidemiologic research.

Etiologic heterogeneity among non-Hodgkin lymphoma subtypes: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Non-Hodgkin lymphoma (NHL) comprises biologically and clinically heterogeneous subtypes. Previously, study size has limited the ability to compare and contrast the risk factor profiles among these heterogeneous subtypes.

METHODS

We pooled individual-level data from 17 471 NHL cases and 23 096 controls in 20 case-control studies from the International Lymphoma Epidemiology Consortium (InterLymph). We estimated the associations, measured as odds ratios, between each of 11 NHL subtypes and self-reported medical history, family history of hematologic malignancy, lifestyle factors, and occupation. We then assessed the heterogeneity of associations by evaluating the variability (Q value) of the estimated odds ratios for a given exposure among subtypes. Finally, we organized the subtypes into a hierarchical tree to identify groups that had similar risk factor profiles. Statistical significance of tree partitions was estimated by permutation-based P values (P NODE).

RESULTS

Risks differed statistically significantly among NHL subtypes for medical history factors (autoimmune diseases, hepatitis C virus seropositivity, eczema, and blood transfusion), family history of leukemia and multiple myeloma, alcohol consumption, cigarette smoking, and certain occupations, whereas generally homogeneous risks among subtypes were observed for family history of NHL, recreational sun exposure, hay fever, allergy, and socioeconomic status. Overall, the greatest difference in risk factors occurred between T-cell and B-cell lymphomas (P NODE < 1.0×10(-4)), with increased risks generally restricted to T-cell lymphomas for eczema, T-cell-activating autoimmune diseases, family history of multiple myeloma, and occupation as a painter. We further observed substantial heterogeneity among B-cell lymphomas (P NODE < 1.0×10(-4)). Increased risks for B-cell-activating autoimmune disease and hepatitis C virus seropositivity and decreased risks for alcohol consumption and occupation as a teacher generally were restricted to marginal zone lymphoma, Burkitt/Burkitt-like lymphoma/leukemia, diffuse large B-cell lymphoma, and/or lymphoplasmacytic lymphoma/Waldenström macroglobulinemia.

CONCLUSIONS

Using a novel approach to investigate etiologic heterogeneity among NHL subtypes, we identified risk factors that were common among subtypes as well as risk factors that appeared to be distinct among individual or a few subtypes, suggesting both subtype-specific and shared underlying mechanisms. Further research is needed to test putative mechanisms, investigate other risk factors (eg, other infections, environmental exposures, and diet), and evaluate potential joint effects with genetic susceptibility.

Rationale and Design of the International Lymphoma Epidemiology Consortium (InterLymph) Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Non-Hodgkin lymphoma (NHL), the most common hematologic malignancy, consists of numerous subtypes. The etiology of NHL is incompletely understood, and increasing evidence suggests that risk factors may vary by NHL subtype. However, small numbers of cases have made investigation of subtype-specific risks challenging. The International Lymphoma Epidemiology Consortium therefore undertook the NHL Subtypes Project, an international collaborative effort to investigate the etiologies of NHL subtypes. This article describes in detail the project rationale and design.

METHODS

We pooled individual-level data from 20 case-control studies (17471 NHL cases, 23096 controls) from North America, Europe, and Australia. Centralized data harmonization and analysis ensured standardized definitions and approaches, with rigorous quality control.

RESULTS

The pooled study population included 11 specified NHL subtypes with more than 100 cases: diffuse large B-cell lymphoma (N = 4667), follicular lymphoma (N = 3530), chronic lymphocytic leukemia/small lymphocytic lymphoma (N = 2440), marginal zone lymphoma (N = 1052), peripheral T-cell lymphoma (N = 584), mantle cell lymphoma (N = 557), lymphoplasmacytic lymphoma/Waldenström macroglobulinemia (N = 374), mycosis fungoides/Sézary syndrome (N = 324), Burkitt/Burkitt-like lymphoma/leukemia (N = 295), hairy cell leukemia (N = 154), and acute lymphoblastic leukemia/lymphoma (N = 152). Associations with medical history, family history, lifestyle factors, and occupation for each of these 11 subtypes are presented in separate articles in this issue, with a final article quantitatively comparing risk factor patterns among subtypes.

CONCLUSIONS

The International Lymphoma Epidemiology Consortium NHL Subtypes Project provides the largest and most comprehensive investigation of potential risk factors for a broad range of common and rare NHL subtypes to date. The analyses contribute to our understanding of the multifactorial nature of NHL subtype etiologies, motivate hypothesis-driven prospective investigations, provide clues for prevention, and exemplify the benefits of international consortial collaboration in cancer epidemiology.