Smoking, variation in N-acetyltransferase 1 (NAT1) and 2 (NAT2), and risk of non-Hodgkin lymphoma: a pooled analysis within the InterLymph consortium

Global burden, risk factors, and trends of non-Hodgkin lymphoma: A worldwide analysis of cancer registries

BACKGROUND

Non-Hodgkin lymphoma (NHL) accounts for 90% of all malignant lymphomas. This study aimed to evaluate the global incidence, mortality, associated risk factors, and temporal trends of NHL by sex, age, and country.

METHODS

Data from 185 countries globally were used for analysis. NHL incidence and mortality were collected via the GLOBOCAN (2020), CI5 series I-X, WHO mortality database, the Nordic Cancer Registries, and the SEER Program. The WHO Global Health Observatory provided country-level, age-standardized prevalence of lifestyle and metabolic risk factors. Trends were examined and reported based on average annual percentage change (AAPC) calculated using Joinpoint regression analysis. Incidence and AAPC are based on data for the last 10 years across countries.

RESULTS

Globally, age-standardized incidence and mortality rates for NHL were recorded at 5.8 and 2.6 per 100,000 individuals, respectively. At country-level, NHL incidence was significantly associated with various factors, including HDI (Human Development Index), GDP per capita, prevalence of tobacco and alcohol consumption, sedentary lifestyle, obesity, hypertension, diabetes and hypercholesterolaemia. Rising trend in NHL incidence was observed, with the highest increase recorded in Estonia (AAPCmale  = 4.15, AAPCfemale  = 5.14), Belarus (AAPCfemale  = 5.13), and Lithuania (AAPCfemale  = 4.68). While overall NHL mortality has been decreasing, certain populations experienced increased mortality over the decade. In Thailand, AAPC for mortality was 31.28% for males and 30.26% for females. Estonia saw an AAPC of 6.46% for males, while Slovakia experienced an AAPC of 4.24% for females. Colombia's AAPC was 1.29% for males and 1.51% for females.

CONCLUSIONS

This study indicates a rising trend of NHL incidence over the past decade- particularly in developed countries, older males, and younger populations. Further research should investigate deeper insights into specific etiology and prognosis of NHL across subtypes, and potential contributors towards these epidemiologic trends.

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.

Association between anthropometry and lifestyle factors and risk of B-cell lymphoma: An exposome-wide analysis

To better understand the role of individual and lifestyle factors in human disease, an exposome-wide association study was performed to investigate within a single-study anthropometry measures and lifestyle factors previously associated with B-cell lymphoma (BCL). Within the European Prospective Investigation into Cancer and nutrition study, 2402 incident BCL cases were diagnosed from 475 426 participants that were followed-up on average 14 years. Standard and penalized Cox regression models as well as principal component analysis (PCA) were used to evaluate 84 exposures in relation to BCL risk. Standard and penalized Cox regression models showed a positive association between anthropometric measures and BCL and multiple myeloma/plasma cell neoplasm (MM). The penalized Cox models additionally showed the association between several exposures from categories of physical activity, smoking status, medical history, socioeconomic position, diet and BCL and/or the subtypes. PCAs confirmed the individual associations but also showed additional observations. The PC5 including anthropometry, was positively associated with BCL, diffuse large B-cell lymphoma (DLBCL) and MM. There was a significant positive association between consumption of sugar and confectionary (PC11) and follicular lymphoma risk, and an inverse association between fish and shellfish and Vitamin D (PC15) and DLBCL risk. The PC1 including features of the Mediterranean diet and diet with lower inflammatory score showed an inverse association with BCL risk, while the PC7, including dairy, was positively associated with BCL and DLBCL risk. Physical activity (PC10) was positively associated with DLBCL risk among women. This study provided informative insights on the etiology of BCL.

Autoimmune/Inflammatory Arthritis Associated Lymphomas: Who Is at Risk?

Specific autoimmune and inflammatory rheumatic diseases have been associated with an increased risk of malignant lymphomas. Conditions such as rheumatoid arthritis (RA), primary Sjögren's syndrome (pSS), systemic lupus erythematosus (SLE), dermatomyositis, and celiac disease have been consistently linked to malignant lymphomas. Isolated cases of lymphomas associated with spondyloarthropathies and autoinflammatory diseases have also been reported. Direct association between autoimmunity and lymphomagenesis has been reinforced by large epidemiological studies. It is still uncertain whether disease specific determinants or phenotypic or treatment related characteristics increase likelihood of lymphomagenesis in these patients. For example, recent literature has indicated a positive correlation between severity of inflammation and risk of lymphomas among RA and Sjögren's syndrome patients. It is also debated whether specific lymphoma variants are more commonly seen in accordance with certain chronic autoimmune arthritis. Previous studies have revealed a higher incidence of diffuse large B-cell lymphomas in RA and SLE patients, whereas pSS has been linked with increased risk of mucosa-associated lymphoid tissue lymphoma. This review summarizes recent literature evaluating risk of lymphomas in arthritis patients and disease specific risk determinants. We also elaborate on the association of autoimmune arthritis with specific lymphoma variants along with genetic, environmental, and therapeutic risk factors.

Mature B cell neoplasms: retrospective analysis of 93 cases diagnosed between 2011 and 2014 in a University Hospital in southern Brazil

Background

According to the 2008 World Health Organization classification, mature B-cell neoplasms are a heterogeneous group of diseases that include B-cell lymphomas and plasma cell disorders. These neoplasms can have very different clinical behaviors, from highly aggressive to indolent, and therefore require diverse treatment strategies.

Objective

The aim of this study was to assess the profile of 93 patients diagnosed with mature B-cell neoplasms monitored between 2011 and 2014.

Methods

A review of patients’ charts was performed and laboratory results were obtained using the online system of the Universidade Federal de Santa Catarina.

Results

The study included 93 adult patients with mature B-cell neoplasms. The most frequent subtypes were multiple myeloma, chronic lymphocytic leukemia, diffuse large B-cell lymphoma, follicular lymphoma, and Burkitt's lymphoma. The median age at diagnosis was 58 years with a male-to-female ratio of 1.3:1. There were statistical differences in terms of age at diagnosis, lactate dehydrogenase activity and Ki-67 expression among the subtypes of B-cell lymphoma. According to the prognostic indexes, the majority of multiple myeloma patients were categorized as high risk, while the majority of chronic lymphocytic leukemia patients were classified as low risk.

Conclusions

This study demonstrates the profile of patients diagnosed with mature B-cell neoplasms in a south Brazilian university hospital. Of the B-cell lymphoma, Burkitt's lymphoma presented particular features regarding lactate dehydrogenase activity levels, Ki-67 expression, age at diagnosis, and human immunodeficiency virus infection.

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.

Medical history, lifestyle, family history, and occupational risk factors for peripheral T-cell lymphomas: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Accounting for 10%-15% of all non-Hodgkin lymphomas in Western populations, peripheral T-cell lymphomas (PTCL) are the most common T-cell lymphoma but little is known about their etiology. Our aim was to identify etiologic risk factors for PTCL overall, and for specific PTCL subtypes, by analyzing data from 15 epidemiologic studies participating in the InterLymph Consortium.

METHODS

A pooled analysis of individual-level data for 584 histologically confirmed PTCL cases and 15912 controls from 15 case-control studies conducted in Europe, North America, and Australia was undertaken. Data collected from questionnaires were harmonized to permit evaluation of a broad range of potential risk factors. Odds ratios (OR) and 95% confidence intervals (CI) were calculated using logistic regression.

RESULTS

Risk factors associated with increased overall PTCL risk with a P value less than .05 included: a family history of hematologic malignancies (OR = 1.92, 95% CI = 1.30 to 2.84); celiac disease (OR = 17.8, 95% CI = 8.61 to 36.79); eczema (OR = 1.41, 95% CI = 1.07 to 1.85); psoriasis (OR = 1.97, 95% CI = 1.17 to 3.32); smoking 40 or more years (OR = 1.92, 95% CI = 1.41 to 2.62); and employment as a textile worker (ever) (OR = 1.58, 95% CI = 1.05 to 2.38) and electrical fitter (ever) (OR = 2.89, 95% CI = 1.41 to 5.95). Exposures associated with reduced overall PTCL risk included a personal history of allergies (OR = 0.69, 95% CI = 0.54 to 0.87), alcohol consumption (ever) (OR = 0.64, 95% CI = 0.49 to 0.82), and having ever lived or worked on a farm (OR = 0.72, 95% CI = 0.55% to 0.95%). We also observed the well-established risk elevation for enteropathy-type PTCL among those with celiac disease in our data. Conclusions Our pooled analyses identified a number of new potential risk factors for PTCL and require further validation in independent series.

Medical history, lifestyle, family history, and occupational risk factors for chronic lymphocytic leukemia/small lymphocytic lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Chronic lymphocytic leukemia (CLL) and small lymphocytic lymphoma (SLL) are two subtypes of non-Hodgkin lymphoma. A number of studies have evaluated associations between risk factors and CLL/SLL risk. However, these associations remain inconsistent or lacked confirmation. This may be due, in part, to the inadequate sample size of CLL/SLL cases.

METHODS

We performed a pooled analysis of 2440 CLL/SLL cases and 15186 controls from 13 case-control studies from Europe, North America, and Australia. We evaluated associations of medical history, family history, lifestyle, and occupational risk factors with CLL/SLL risk. Multivariate logistic regression analyses were used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

We confirmed prior inverse associations with any atopic condition and recreational sun exposure. We also confirmed prior elevated associations with usual adult height, hepatitis C virus seropositivity, living or working on a farm, and family history of any hematological malignancy. Novel associations were identified with hairdresser occupation (OR = 1.77, 95% CI = 1.05 to 2.98) and blood transfusion history (OR = 0.79, 95% CI = 0.66 to 0.94). We also found smoking to have modest protective effect (OR = 0.9, 95% CI = 0.81 to 0.99). All exposures showed evidence of independent effects.

CONCLUSIONS

We have identified or confirmed several independent risk factors for CLL/SLL supporting a role for genetics (through family history), immune function (through allergy and sun), infection (through hepatitis C virus), and height, and other pathways of immune response. Given that CLL/SLL has more than 30 susceptibility loci identified to date, studies evaluating the interaction among genetic and nongenetic factors are warranted.

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.

Biomarkers of susceptibility to chemical carcinogens: the example of non-Hodgkin lymphomas

BACKGROUND

Genetic susceptibly to suspected chemical and environmental carcinogens may modify the response to exposure. The aim of this review was to explore the issues involved in the study of gene-environment interactions, and to consider the use of susceptibility biomarkers in cancer epidemiology, using non-Hodgkin lymphoma (NHL) as an example.

SOURCES OF DATA

PubMed, EMBASE and Web of Science were searched for peer-reviewed articles considering biomarkers of susceptibility to chemical, agricultural and industrial carcinogens in the aetiology of NHL.

AREAS OF AGREEMENT

The results suggest a modifying role for genetic susceptibility to a number of occupational and environmental exposures including organochlorines, chlorinated solvents, chlordanes and benzene in the aetiology of NHL. The potential importance of these gene-environment interactions in NHL may help to explain the lack of definitive carcinogens identified to date for this malignancy.

AREAS OF CONTROVERSY

Although a large number of genetic variants and gene-environment interactions have been explored for NHL, to date replication is lacking and therefore the findings remain to be validated.

GROWING POINTS AND AREAS TIMELY FOR DEVELOPING RESEARCH

These findings highlight the need for novel standardized methodologies in the study of genetic susceptibility to chemical carcinogens.

Inter-ethnic differences in genetic polymorphisms of xenobiotic-metabolizing enzymes (CYP1A1, CYP2D6, NAT1 and NAT2) in healthy populations: correlation with the functional in silico prediction

Several studies have shown that many polymorphisms of the xenobiotic-metabolizing enzymes (XME) affect either enzymatic functions or are associated with various aspects of human health. Owing to the presence of these single nucleotide variants (SNVs), differences in detoxification capacity have been observed between many ethnicities. The aim of this investigation was to study the prevalence of four polymorphisms in XME among various ethnic groups. Attention was focused on polymorphisms of CYP2D6 (rs1058172, G>A, p.Arg365His), CYP1A1 (rs4646421, c.-26-728C>T), NAT1 (rs4921880, c.-85-1014T>A) and NAT2 (rs1208, A>G, p.Arg268Lys). These polymorphisms were analyzed in 261 healthy Tunisians individuals in comparison with different ethnic backgrounds from hapmap database. In addition, in silico functional prediction was also performed to determine the loss of function variants. Our results demonstrated that population's origins widely affect the genetic variability of XME enzymes and Tunisians show a characteristic pattern. In silico predictions showed a deleterious effect for p.Arg268Lys substitution on CYP2D6 function, findings confirmed its key role played in cancer susceptibility. These data show that detoxification genes structures depend on the studied population. This suggests that ethnic differences impact on disease risk or response to drugs and therefore should be taken into consideration in genetic association studies focusing on XME enzymes. Our results provide the first report on these SNV in Tunisian population and could be useful for further epidemiological investigations including targeted therapy.

Leukemia, lymphoma and multiple myeloma mortality (1950-1999) and incidence (1969-1999) in the Eldorado uranium workers cohort

Uranium workers are chronically exposed to low levels of radon decay products (RDP) and gamma (γ) radiation. Risks of leukemia from acute and high doses of γ-radiation are well-characterized, but risks from lower doses and dose-rates and from RDP exposures are controversial. Few studies have evaluated risks of other hematologic cancers in uranium workers. The purpose of this study was to analyze radiation-related risks of hematologic cancers in the cohort of Eldorado uranium miners and processors first employed in 1932-1980 in relation to cumulative RDP exposures and γ-ray doses. The average cumulative RDP exposure was 100.2 working level months and the average cumulative whole-body γ-radiation dose was 52.2 millisievert. We identified 101 deaths and 160 cases of hematologic cancers in the cohort. Overall, male workers had lower mortality and cancer incidence rates for all outcomes compared with the general Canadian male population, a likely healthy worker effect. No statistically significant association between RDP exposure or γ-ray doses, or a combination of both, and mortality or incidence of any hematologic cancer was found. We observed consistent but non-statistically significant increases in risks of chronic lymphocytic leukemia (CLL) and Hodgkin lymphoma (HL) incidence and non-Hodgkin lymphoma (NHL) mortality with increasing γ-ray doses. These findings are consistent with recent studies of increased risks of CLL and NHL incidence after γ-radiation exposure. Further research is necessary to understand risks of other hematologic cancers from low-dose exposures to γ-radiation.

Lymphoma development in patients with autoimmune and inflammatory disorders--what are the driving forces?

For decades, it has been known that patients with certain autoimmune and inflammatory disorders, such as rheumatoid arthritis (RA) and primary Sjögren's syndrome (pSS), have an increased risk of developing malignant lymphoma. Although the clinico-biological reasons for this association remain largely unknown, our knowledge has improved and new insights have been obtained. First, the direct link between autoimmunity and lymphomagenesis has been strengthened by large epidemiological studies showing a consistent risk increase of lymphoma associated with certain autoimmune/inflammatory conditions in independent cohorts from different countries. Second, a number of local and systemic disease-related risk factors in these diseases have been repeatedly linked to lymphoma development, with the prime examples being disease severity and the degree of inflammatory activity. Considering the key role of B- and T-cell activation in the pathogenesis of both autoimmunity and lymphoma, it is perhaps not surprising that longstanding chronic inflammation and/or antigen stimulation have emerged as major predisposing factors of lymphoma in patients with active autoimmune disease. Finally, increasing evidence suggests that lymphomas associated with autoimmunity constitute a different spectrum of entities compared to lymphomas arising in patients without any known autoimmune or inflammatory conditions, pointing to a different pathobiology. In this review, we summarize the recent literature that supports a direct or indirect link between immune-mediated disease and lymphoma and describe the characteristics of lymphomas developing in the different diseases. We also discuss molecular, genetic and microenvironmental factors that may come into play in the pathobiology of these disorders.

Occupational extremely low-frequency magnetic field exposure and selected cancer outcomes in a prospective Dutch cohort

PURPOSE

To investigate the association between exposure to occupational extremely low-frequency magnetic fields (ELF-MF) and the risk of a priori selected cancer outcomes within the prospective Netherlands Cohort Study.

METHODS

120,852 men and women aged 55-69 years at time of enrollment in 1986 were followed up (17.3 years) for incident lung, breast and brain cancer, and hemato-lymphoproliferative malignancies. Information on occupational history and potential confounders such as sex, age, smoking, alcohol use, and attained educational level were collected at baseline through a self-administered questionnaire. Occupational ELF-MF exposure was assigned with a job-exposure matrix. Using a case-cohort approach, associations with cancer incidence were analyzed with Cox regression stratified by sex, using three exposure metrics: (1) ever had a job with low or high exposure to ELF-MF versus background, (2) duration of exposure, and (3) cumulative exposure.

RESULTS

None of the exposure metrics showed an effect on incidence for lung, breast, and brain cancer, nor any of the assessed subtypes in men and women. Of the hemato-lymphoproliferative malignancies in men, ever high exposed to ELF-MF showed a significant association with acute myeloid leukemia (AML) [hazard ratio (HR) 2.15; 95 % confidence interval (CI) 1.06-4.35] and follicular lymphoma (FL) (HR 2.78; 95 % CI 1.00-5.77). Cumulative exposure to ELF-MF showed a significant, positive association with FL but not AML among men.

CONCLUSIONS

In this large prospective cohort study, we found some indications of an increased risk of AML and FL among men with occupational ELF-MF exposure. These findings warrant further investigation.