Personal use of hair dye and the risk of certain subtypes of non-Hodgkin lymphoma

Anthropometric indicators may explain the high incidence of follicular lymphoma in Europeans: Results from a bidirectional two-sample two-step Mendelian randomisation

BACKGROUND

Non-Hodgkin's lymphoma incidence rates vary between European and Asian populations. The reasons remain unclear. This two-sample two-step Mendelian randomisation (MR) study aimed to investigate the causal relationship between anthropometric indicators (AIs) and diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) and the possible mediating role of basal metabolic rate (BMR) in Europe.

METHODS

We used the following AIs as exposures: body mass index (BMI), whole-body fat mass (WBFM), whole-body fat-free mass (WBFFM), waist circumference(WC), hip circumference(HC), standing height (SH), and weight(Wt). DLBCL and FL represented the outcomes, and BMR was a mediator. A two-sample MR analysis was performed to examine the association between AIs and DLBCL and FL onset. We performed reverse-MR analysis to determine whether DLBCL and FL interfered with the AIs. A two-step MR analysis was performed to determine whether BMR mediated the causality.

FINDINGS

WBFFM and SH had causal relationships with FL. A causal association between AIs and DLBCL was not observed. Reverse-MR analysis indicated the causal relationships were not bidirectional. Two-step MR suggested BMR may mediate the causal effect of WBFFM and SH on FL.

CONCLUSIONS

We observed a causal relationship between WBFFM and SH and the onset of FL in Europeans, Which may explain the high incidence of follicular lymphoma in Europeans.

Assessing haematological parameters and probable toxicity analysis in two coastal fish species at harbouring areas of Digha coastal belt, West Bengal, India

Coastal ecosystems are vital for maintaining the biodiversity and human livelihoods, but they are increasingly subjected to anthropogenic pressures, including pollution from various sources. Present work intends to assess the possible threats in coastal ecosystem as well as coastal fish species, in particular, through haematological parameters caused due to exposure of environmental contaminants like polycyclic aromatic hydrocarbons (PAHs), potentially toxic metals (PTMs), etc. This study analysed the haematological parameters and probable toxicity levels in two important coastal fish species, viz., Mystus sp. and Mugil sp. widely available in Digha coastal belt. Different haematological parameters, such as WBCs (White Blood Cells), Lym (Lymphocytes), Gran (Granulocytes), Mid (Monocytes), RBCs (Red Blood Cells), HCT (Haematocrit) value, MCV (Mean Corpuscular Volume), MCH (Mean Corpuscular Haemoglobin), MCHC (Mean Corpuscular Haemoglobin Concentration), RDW- CV (Red Cells Distribution Width-Co-efficient of Variation), RDW- SD (Red Cells Distribution Width-Standard Deviation), PLT (Total Platelet Count), MPV (Mean Platelet Volume), PDW- SD (Platelet Distribution Width-Standard Deviation), PDW- CV (Platelet Distribution Width-Co-efficient of Variation), PCT (Plateletcrit), PLCR (Platelet Large Cell Ratio), PLCC (Platelet Large Cell Count) and many others were measured directly through Erba H360 Haematology Analyser, simultaneously air dried blood smear was stained by Haematoxylin-Eosin(H-E) and Giemsa stain for assessing morphometric alterations of RBCs, WBCs, platelets as well as to determine the differential counts of WBCs by observing through Leica DM2000 microscope. Evidence of several abnormalities in the erythrocyte's nucleus (ENAs) and the abundance of abnormal celled erythrocytes (ECAs), carcinoma (lymphoproliferative disorder, polycythaemia vera, Hodgkin lymphoma and non-Hodgkin lymphoma), elevation of WBCs content, Lym %(Lymphocyte percentage), Eo(Eosinophils), monocytes, HCT and gross depletion of Ne(Neutrophils), basophils, and PLCR levels indicated a sign of major impact of contamination to two intoxicated fishes which may also affect the human being through food chain and may result into leukaemia in mammalian species, finally. However, comprehensive evaluation of the long-term impacts of the contaminants like PAHs and/or PTMs, etc., on fish populations, human health risk and coastal ecosystem is required to be addressed.

Epidemiology and etiology of diffuse large B-cell lymphoma

As the most common non-Hodgkin lymphoma subtype, diffuse large B-cell lymphoma (DLBCL) incidence patterns generally parallel that for NHL overall. Globally, DLBCL accounts for a third of all NHLs, ranging between 20% and 50% by country. Based on United States (U.S.) cancer registry data, age-standardized incidence rate for DLBCL was 7.2 per 100,000. DLBCL incidence rises with age and is generally higher in males than females; in the U.S., incidence is highest among non-Hispanic whites (9.2/100,000). Like NHL incidence, DLBCL incidence rose in the first half of the 20th century but has largely plateaued. However, there is some evidence that incidence rates are rising in areas of historically low rates, such as Asia; there are also estimates for rising DLBCL incidence in the near future due to the changing demographics in developed countries whose aging population is growing. Established risk factors for DLBCL include those that result in severe immune deficiency such as HIV/AIDS, inherited immunodeficiency syndromes, and organ transplant recipients. Factors that lead to chronic immune dysregulations are also established risk factors, and include a number of autoimmune conditions (eg, Sjögren syndrome, systemic lupus erythematosus, rheumatoid arthritis), viral infections (eg, HIV, KSHV/HHV8, HCV, EBV), and obesity. Family history of NHL/DLBCL, personal history of cancer, and multiple genetic susceptibility loci are also well-established risk factors for DLBCL. There is strong evidence for multiple environmental exposures in DLBCL etiology, including exposure to trichloroethylene, benzene, and pesticides and herbicides, with recent associations noted with glyphosate. There is also strong evidence for associations with other viruses, such as HBV. Recent estimates suggest that obesity accounts for nearly a quarter of DLBCLs that develop, but despite recent gains in the understanding of DLBCL etiology, the majority of disease remain unexplained. An understanding of the host and environmental contributions to disease etiology, and concerted efforts to expand our understanding to multiple race/ethnic groups, will be essential for constructing clinically relevant risk prediction models and develop effective strategies for disease prevention.

A Systematic Review on Childhood Non-Hodgkin Lymphoma: An Overlooked Phenomenon in the Health and Research Sector of Bangladesh

Globally, childhood cancer, particularly non-Hodgkin lymphomas (NHLs), is a prevalent concern. However, the difficulty becomes even more distressing in lower-middle-income nations such as Bangladesh. The insufficiency of research, resources, inadequate guidelines, expensive treatment costs, and specialized knowledge exacerbate the challenges associated with the treatment of certain types of cancers. Our investigation looked extensively into the circumstances prevailing in Bangladesh, with the objective of providing a comprehensive overview of the current status and approaches to managing NHL in the country. Through this work, our intention was to illuminate the domains that require immediate focus and assistance. To get insight into the present state of NHL in Bangladesh, our analysis focused on a selection of seven research articles and two case reports published between 2018 and 2023. In order to ensure the integrity and consistency of our review, we conducted a detailed selection procedure, employing the systematic PRISMA review methodology. From a pool of 294 papers, we selected the ones that met our predetermined criteria. These papers were sourced from reputable academic databases, such as Google Scholar and PubMed. The findings of our study indicate a higher prevalence of NHL among children in Bangladesh compared to Hodgkin lymphoma (HL). Additionally, this phenomenon exhibits a higher prevalence among male individuals. Our study revealed that in Bangladesh, there is a lack of a dedicated guideline or research center specifically focused on NHL. Additionally, the number of research centers and research dedicated to cancer treatment as a whole is limited. Our research aims to offer a complete analysis of NHL in the context of Bangladesh, with the intention of offering valuable guidance to healthcare professionals and policymakers. The utilization of our research outcomes has the potential to enhance patient care, facilitate the development of more effective clinical protocols, and promote greater accessibility and affordability of therapies. This has the potential to provide improved cancer care not only in Bangladesh but also in other comparable contexts worldwide.

Potential Pathogenic Impact of Cow’s Milk Consumption and Bovine Milk-Derived Exosomal MicroRNAs in Diffuse Large B-Cell Lymphoma

Epidemiological evidence supports an association between cow’s milk consumption and the risk of diffuse large B-cell lymphoma (DLBCL), the most common non-Hodgkin lymphoma worldwide. This narrative review intends to elucidate the potential impact of milk-related agents, predominantly milk-derived exosomes (MDEs) and their microRNAs (miRs) in lymphomagenesis. Upregulation of PI3K-AKT-mTORC1 signaling is a common feature of DLBCL. Increased expression of B cell lymphoma 6 (BCL6) and suppression of B lymphocyte-induced maturation protein 1 (BLIMP1)/PR domain-containing protein 1 (PRDM1) are crucial pathological deviations in DLBCL. Translational evidence indicates that during the breastfeeding period, human MDE miRs support B cell proliferation via epigenetic upregulation of BCL6 (via miR-148a-3p-mediated suppression of DNA methyltransferase 1 (DNMT1) and miR-155-5p/miR-29b-5p-mediated suppression of activation-induced cytidine deaminase (AICDA) and suppression of BLIMP1 (via MDE let-7-5p/miR-125b-5p-targeting of PRDM1). After weaning with the physiological termination of MDE miR signaling, the infant’s BCL6 expression and B cell proliferation declines, whereas BLIMP1-mediated B cell maturation for adequate own antibody production rises. Because human and bovine MDE miRs share identical nucleotide sequences, the consumption of pasteurized cow’s milk in adults with the continued transfer of bioactive bovine MDE miRs may de-differentiate B cells back to the neonatal “proliferation-dominated” B cell phenotype maintaining an increased BLC6/BLIMP1 ratio. Persistent milk-induced epigenetic dysregulation of BCL6 and BLIMP1 expression may thus represent a novel driving mechanism in B cell lymphomagenesis. Bovine MDEs and their miR cargo have to be considered potential pathogens that should be removed from the human food chain.

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.

Hair Dye Ingredients and Potential Health Risks from Exposure to Hair Dyeing

Given the worldwide popularity of hair dyeing, there is an urgent need to understand the toxicities and risks associated with exposure to chemicals found in hair dye formulations. Hair dyes are categorized as oxidative and nonoxidative in terms of their chemical composition and ingredients. For several decades, the expert panel's Cosmetic Ingredient Review (CIR) has assessed the safety of many of the chemicals used in hair dyes; however, a comprehensive review of hair dye ingredients and the risk of exposure to hair dyeing has not been documented. Herein, we review the safety of the various chemicals in oxidative and nonoxidative hair dyes, toxicities associated with hair dyeing, and the carcinogenic risks related to hair dyeing. While many compounds are considered safe for users at the concentrations in hair dyes, there are conflicting data about a large number of hair dye formulations. The CIR expert panel has ratified a number of coloring ingredients for hair dyes and banned a series of chemicals as carcinogenic to animals and unsafe for this application. The use of these chemicals as raw materials for producing hair dyes may result in the synthesis of other contaminants with potential toxicities and increased risk of carcinogenesis. It is an open question whether personal or occupational hair dyeing increases the risk of cancer; however, in specific subpopulations, a positive association between hair dye use and cancer occurrence has been reported. To address this question, a better understanding of the chemical and mechanistic basis of the reported toxicities of hair dye mixtures and individual hair dye ingredients is needed. It is anticipated that in-depth chemical and systems toxicology studies harnessing modern and emerging techniques can shed light on this public health concern in the future.

Epidemiology beyond its limits

In 1995, journalist Gary Taubes published an article in Science titled "Epidemiology faces its limits," which questioned the utility of nonrandomized epidemiologic research and has since been cited more than 1000 times. He highlighted numerous examples of research topics he viewed as having questionable merit. Studies have since accumulated for these associations. We systematically evaluated current evidence of 53 example associations discussed in the article. Approximately one-quarter of those presented as doubtful are now widely viewed as causal based on current evaluations of the public health consensus. They include associations between alcohol consumption and breast cancer, residential radon exposure and lung cancer, and the use of tanning devices and melanoma. This history should inform current debates about the reproducibility of epidemiologic research results.

Association between hair dye use and cancer in women: a systematic review and meta-analysis of case-control studies

Background

The use of hair dye for cosmetic purposes appears to be increasing worldwide. As 50-80% of women use hair dye throughout their lifetimes, the possible association between hair dye use and cancer is a public health concern.

Method

This systematic review was performed by retrieving studies from PubMed, Scopus, WOS, and ProQuest databases. The inclusion criteria were case-control studies evaluating the association between hair dye use and cancer in women. Women with cancer who have used any hair dye were the focus of our study.

Results

The present study combined 28 studies, to assess the association between hair dye use and cancer. The pooled odds ratio (OR) of hematopoietic system cancers among those who have generally ever used any type of hair dyes was 1.10 (95% CI:1.01-1.20) in 17 studies. In 11 studies investigating hair dye made before and after 1980 as a risk factor for cancer, the pooled OR for cancer was 1.31(95% CI:1.08-1.59). Likewise, in the 13 studies that evaluated the association of light and dark hair dye with cancer, the risk among those using dark hair dye increased by 9%, compared to non-users (OR=1.09; 95% CI:0.95-1.25).

Conclusion

The present study suggests that, although the use of hair dye may increase the risk of cancer among users, a more detailed evaluation is required to assess the type of hair dye use in terms of guidelines and metrics.

Associations of hair dye and relaxer use with breast tumor clinicopathologic features: Findings from the Women's circle of Health Study

BACKGROUND

Building upon our earlier findings of significant associations between hair dye and relaxer use with increased breast cancer risk, we evaluated associations of select characteristics of use with breast tumor clinicopathology.

METHODS

Using multivariable-adjusted models we examined the associations of interest in a case-only study of 2998 women with breast cancer, overall and stratified by race and estrogen receptor (ER) status, addressing multiple comparisons using Bonferroni correction.

RESULTS

Compared to salon application of permanent hair dye, home kit and combination application (both salon and home kit application) were associated with increased odds of poorly differentiated tumors in the overall sample. This association was consistent among Black (home kit: OR 2.22, 95 % CI: 1.21-5.00; combination: OR 2.46, 95 % CI: 1.21-5.00), but not White women, and among ER+ (home kit: OR 1.47, 95 % CI: 0.82-2.63; combination: OR 2.98, 95 % CI: 1.62-5.49) but not ER-cases. Combination application of relaxers was associated with increased odds of tumors >2.0 cm vs. <1.0 cm (OR = 1.82, 95 % CI: 1.23-2.69). Longer duration and earlier use of relaxers and combination application of permanent hair dyes and relaxers were associated with breast tumor features including higher tumor grade and larger tumor size, which often denote more aggressive phenotypes, although the findings did not maintain significance with Bonferroni correction.

CONCLUSIONS

These novel data support reported associations between hair dye and relaxer use with breast cancer, showing for the first time, associations with breast tumor clinicopathologic features. Improved hair product exposure measurement is essential for fully understanding the impact of these environmental exposure with breast cancer and to guide risk reduction strategies in the future.

Thermostable bacterial laccase for sustainable dyeing using plant phenols

Laccase is regarded as an efficacious eco-friendly enzyme in various industries. Thus, various laccases have been explored to mitigate the environmental effects of conventional industrial processing; however, the prospects of laccase in hair dyeing have not been thoroughly explored to date. On account of the adverse environmental and health-related issues posed by chemical hair dyeing, laccase as a natural alternative in dyeing hair has recently gained attention. In this study, we executed hair dyeing with different colours and shades of hair dyes developed from natural plant phenols, including ferulic acid, gallic acid, catechol, and syringaldehyde, catalysed by a novel thermostable bacterial laccase (LacT) from Brevibacillus agri. The dyed hair was characterised in terms of its colourimetric parameters (L*, a*, and b*), colour strength (K/S), reflectance (R) and colour durability. L* means luminosity and is defined by L* values from 0 (black) to 100 (white). A positive value of a* means red shades and a negative value indicates green shades. A positive value of b* shows yellow shades and a negative value indicates blue shades. Optical microscopy of circular and longitudinal sections of the dyed hair revealed that the laccase-catalysed dyes did not merely stick to the surface; instead, they well-penetrated the hair. Furthermore, the dyeing process did not affect the surface morphology of the dyed hair. The dyed hair also exhibited a desirable range of colour diversity in terms of market-driven demands and showed considerable resistance to fading during shampooing and pH alterations. Post-dyeing, the texture and tensile strength of the dyed hair remained nearly unchanged. Overall, the outcomes suggest that LacT holds high potential to be exploited extensively in the hair dyeing industry as an alternative to chemical hair dyes.

Laccase is regarded as an efficacious eco-friendly enzyme in various industries.

Seaweed-Based Molecules and Their Potential Biological Activities: An Eco-Sustainable Cosmetics

Amongst the countless marine organisms, seaweeds are considered as one of the richest sources of biologically active ingredients having powerful biological activities. Seaweeds or marine macroalgae are macroscopic multicellular eukaryotic photosynthetic organisms and have the potential to produce a large number of valuable compounds, such as proteins, carbohydrates, fatty acids, amino acids, phenolic compounds, pigments, etc. Since it is a prominent source of bioactive constituents, it finds diversified industrial applications viz food and dairy, pharmaceuticals, medicinal, cosmeceutical, nutraceutical, etc. Moreover, seaweed-based cosmetic products are risen up in their demands by the consumers, as they see them as a promising alternative to synthetic cosmetics. Normally it contains purified biologically active compounds or extracts with several compounds. Several seaweed ingredients that are useful in cosmeceuticals are known to be effective alternatives with significant benefits. Many seaweeds' species demonstrated skin beneficial activities, such as antioxidant, anti-melanogenesis, antiaging, photoprotection, anti-wrinkle, moisturizer, antioxidant, anti-inflammatory, anticancer and antioxidant properties, as well as certain antimicrobial activities, such as antibacterial, antifungal and antiviral activities. This review presents applications of bioactive molecules derived from marine algae as a potential substitute for its current applications in the cosmetic industry. The biological activities of carbohydrates, proteins, phenolic compounds and pigments are discussed as safe sources of ingredients for the consumer and cosmetic industry.

Iron Gall Ink Revisited: A Surfactant-Free Emulsion Technology for Black Hair-Dyeing Formulation

Inspired by the redox reactions in the preparation of the iron gall ink that has been used in Europe since the Middle Ages, we developed a technology for forming the oil-in-water emulsions, without any surfactants and emulsifiers, by homogenizing a mixture of tannic acid, gallic acid, Fe(D-gluconate)2, and natural oil, which are all approved as cosmetic ingredients. Various plant-derived oils, such as argan oil, olive oil, sunflower oil, grape seed oil, hemp seed oil, peppermint oil, rosemary oil, and ylang-ylang oil, were used as an oil phase for the emulsion formation, and all the fabricated emulsions exhibited the capability of black hair-dyeing. This surfactant-free emulsion technology for combining the hair-dyeing capability of Fe3+–tannin complex with the hair-fortifying property of natural oil would have great impact on the hair-cosmetic industry.

Linking Environmental Exposures to Molecular Pathogenesis in Non-Hodgkin Lymphoma Subtypes

Non-Hodgkin lymphoma comprises a heterogeneous group of hematologic malignancies, with about 60 subtypes that arise via various pathogenetic mechanisms. Although establishing etiology for specific NHL subtypes has been historically difficult given their relative rarity, environmental exposures have been repeatedly implicated as risk factors across many subtypes. Large-scale epidemiologic investigations have pinpointed chemical exposures in particular, but causality has not been established, and the exact biologic mechanisms underpinning these associations are unclear. Here we review chemical exposures that have been associated with development of NHL subtypes and discuss their biologic plausibility based on current research.

Epidemiology and Etiology of Leukemia and Lymphoma

Available evidence suggests that the incidence of leukemia and lymphoma tends to be higher in highly developed regions of the world and among Whites in the United States. Temporal trends in incidence are dynamic and multifactorial; for instance, the incidence of non-Hodgkin's lymphoma increased around the turn of the century, in part because of the acquired immune deficiency syndrome (AIDS) epidemic. Most leukemias and lymphomas are sporadic and the specific etiology remains elusive. Still, research shows that these malignancies often develop in the context of genetic abnormalities, immunosuppression, and exposure to risk factors like ionizing radiation, carcinogenic chemicals, and oncogenic viruses. The prognosis varies by subtype, with poorer survival outcomes for acute leukemias among adults, and more favorable outcomes for Hodgkin's lymphoma. At a time when specific prevention efforts targeting these malignancies are nonexistent, there is a great need to ensure equitable access to diagnostic services and treatments worldwide.

Epidemiology of Follicular Lymphoma

Follicular lymphoma (FL) is a common indolent lymphoma subtype in Western countries. FL incidence increases with age, and shows considerable variation by race/ethnicity and geography. In the United States and France, FL incidence has been stable since 2000, whereas in other Western and Asian countries it has been increasing. Five-year relative survival rates have been increasing in Western and Asian countries. Progress on identifying FL-specific risk factors has accelerated with the implementation of the InterLymph nested classification and the availability of larger epidemiologic studies and pooled analyses. Identification of risk factors for FL requires further research.

Therapeutics of premature hair graying: A long journey ahead

Premature graying of hair has major psychosocial and socioeconomic repercussion, as it is considered as a sign of hastily progressing old age, ill health and often leads to loss of self-esteem. Hair is said to gray prematurely when it happens before the age of 20 years in Caucasians, 25 years in Asians, and 30 years in Africans. The hair color chiefly depends on melanin pigment, and fabrication of this pigment takes place in melanosomes through the process of melanogenesis. This complex biochemical pathway (melanogenesis) is further dependent on tyrosinase which acts as fuel.The normal human scalp is subjected to various factors categorized as intrinsic and extrinsic leading to graying of hair. Intrinsic factors comprise of variants responsible for changes at genetic level while extrinsic factors include air pollution, ultraviolet radiation, smoking, and nutrition. It has been proposed that direct or indirect effect of all these factors results in the generation of reactive oxygen species (ROS), thus leading to further damage. Though research has expanded in last few years in terms of microscopic, biochemical (hormonal, enzymatic), and molecular changes happening within hair follicle/shaft, still the exact mechanism leading to premature graying of hair is not well understood. Probable solutions toward this quandary are diet, herbal remedies, and temporary hair colorants. Ironically, the latter one being the most common has various side effects such as allergic reactions, inflammation, and hair loss. The aim of this paper was to review the manifestation and probable future interventions in preventing premature hair graying.

Diagnosis and management of follicular lymphoma: A comprehensive review

Follicular Lymphoma (FL) is an indolent lymphoma and may have various clinical courses. Worldwide, FL is the second most common non-Hodgkin lymphoma (NHL) type after diffuse large B-cell lymphoma. In this review article, the author is discussing relevant diagnostic tools, prognostic factors, and updated study results on the management of patients with newly diagnosed and relapsed/refractory FL. Controversies in the treatment, maintenance therapy, stem cell transplantation, and novel treatment approaches will be comprehensively discussed.

Distinctive incidence patterns of follicular lymphoma in Taiwan: Implications of ethnic differences

BACKGROUND

Follicular lymphoma (FL) is less prevalent in Asians, but detailed epidemiological analyses were not available. This study aimed to characterize the epidemiologic features of FL in Taiwan to explore the factors relevant to disease development and prognosis.

METHODS

We obtained epidemiological data for Taiwanese citizens during 1990-2012 from Taiwan's National Cancer Registry Database, and the corresponding data for US Caucasians from the Surveillance, Epidemiology, and End Results Program. Changes in incidence rates were evaluated with age-period-cohort (APC) analyses. Patient outcomes were compared with 5-year relative survival rates (RS) estimates.

RESULTS

Incidence rates of FL in Taiwan increased continuously during the study period (0.34 to 0.91 per 100 000 person-year from 1993-1997 to 2008-2012 in men, and from 0.29 [1993-1997] to 0.81 [2008-2012] in women), while rates in the US remained stable in both sexes, ranging between 3.73 and 3.96 in men and between 3.24 and 3.55 in women. Estimates of average annual percentage changes in incidence were significantly positive in Taiwan, but not in US Caucasians. Notably, the APC analysis identified a strong birth-cohort effect in Taiwan, corresponding to environmental alterations present during the study period. The estimated 5-year RS rates in both populations showed steady improvement, but the RS in Taiwanese patients was consistently 10% lower than in US Caucasians.

CONCLUSION

A distinct increasing trend of incidence with a strong birth-cohort effect was identified in Taiwan, providing evidence of the association between environmental factors and disease development.

A Meta-Analysis on the Relationship Between Hair Dye and the Incidence of Non-Hodgkin's Lymphoma

BACKGROUND

Epidemiologic studies have suggested hair dye to be a risk factor for many cancers. However, previous studies on the association between the personal use of hair dye and risk of non-Hodgkin's lymphoma (NHL) have been inconclusive.

METHODS

The PubMed, Embase, Cochrane Library, and Web of Science databases, as well as the references cited in included studies, were searched for relevant studies up to February 10, 2015. Odds ratios (OR) with 95% confidence intervals (CI) were applied to assess the strength of the association. Publication bias was evaluated using a funnel plot by Egger's and Begg's tests.

RESULTS

A total of 16 studies were included in the analysis, including 13 case-control studies and 3 cohort studies. The present meta-analysis results revealed that the risk of NHL in a high population of hair dye users was 14% (OR 1.14, 95% CI 1.01-1.29). Furthermore, individuals who used more than 20 pack-years of hair dye had increased risk of NHL.

CONCLUSION

The outcomes indicate that hair dye use increases the risk of NHL, especially for females. Hence, people who frequently use hair dyes or have been using hair dyes for more than 20 years should minimize their exposure to hair dye products to prevent the risk of NHL.

Use of flow cytometry in the phenotypic diagnosis of hodgkin's lymphoma

Hodgkin's lymphoma (HL) has a unique immunophenotype derived from immunohistochemistry (positive for CD15, CD30, and Pax-5; negative for CD3, CD20 in most cases, and CD45). The knowledge gained over recent years enables better diagnosis, prognosis, and treatment of HL. Flow cytometry as a tool for the diagnosis of classic HL has not been useful in the past due to the difficulty in isolating Reed-Sternberg cells as they are admixed in a rich inflammatory background which consists mainly of T cells, B cells, eosinophils, histiocytes, and plasma cells. However, in the recent past, several studies have tried to identify Reed-Sternberg cells using flow cytometry on fine needle aspiration or tissue biopsy of lymph nodes to confirm or supplement immunohistochemistry staining in diagnosis. Newer and more sensitive tools such as flow cytometry can be used for diagnosis, technology that may have been difficult in the past for diagnosis of this lymphoma subtype. Using flow cytometry, diagnosis is faster and could lead to point-of-care technology especially where we have typical immunophenotype signatures. © 2018 International Clinical Cytometry Society.

Personal use of hair dyes and risk of leukemia: a systematic literature review and meta-analysis

The objective of this study was to examine the association between personal use of hair dyes and the risk of leukemia. We conducted a systematic literature review of epidemiology studies reporting leukemia‐specific cancer risks among hair dye users, and estimated the meta‐relative risk (meta‐RR) and corresponding 95% confidence interval (95% CI) of leukemia, comparing hair dye users to nonusers. When data from all 20 studies that met the inclusion criteria were combined, ever use of hair dye was associated with a nonstatistically significant increased risk of leukemia, meta‐RR = 1.09 (95% CI: 0.97–1.22). When restricted to studies that adjusted for smoking, ever use of hair dye was not associated with leukemia, meta‐RR = 0.99 (95% CI: 0.76–1.29). A statistically significant increased risk of leukemia was associated with permanent hair dye use (meta‐RR = 1.19 [95% CI: 1.07–1.33]), dark hair dye use (meta‐RR = 1.29 [95% CI: 1.11–1.50]), hair dye use among males (meta‐RR = 1.42 [95% CI: 1.01–2.00]), hair dye use pre‐1980 (meta‐RR = 1.49 [95% CI: 1.21–1.83]), and hair dye use for ≥15 years (meta‐RR = 1.35 [95% CI: 1.13–1.62]). Overall, findings suggest that ever use of hair dye is not a significant risk factor for leukemia. Certain hair dye use characteristics were associated with a statistically significant increased risk, but further research is required to determine whether these associations truly reflect a risk of leukemia due to methodological limitations in the underlying studies.

Non-Hodgkin lymphoma

Lymphomas can affect any organ in the body, present with a wide range of symptoms, and be seen by primary care physicians and physicians from most specialties. They are traditionally divided into Hodgkin's lymphoma (which accounts for about 10% of all lymphomas) and non-Hodgkin lymphoma, which is the topic of this Seminar. Non-Hodgkin lymphoma represents a wide spectrum of illnesses that vary from the most indolent to the most aggressive malignancies. They arise from lymphocytes that are at various stages of development, and the characteristics of the specific lymphoma subtype reflect those of the cell from which they originated. Since this topic was last reviewed in The Lancet in 2012, advances in understanding the biology and genetics of non-Hodgkin lymphoma and the availability of new diagnostic methods and therapies have improved our ability to manage patients with this disorder.

Relations Between Residential Proximity to EPA-Designated Toxic Release Sites and Diffuse Large B-Cell Lymphoma Incidence

OBJECTIVES

Examining the spatial patterns of diffuse large B-cell lymphoma (DLBCL) incidence and residential proximity to toxic release locations may provide insight regarding environmental and sociodemographic risk factors.

METHODS

We linked and geocoded cancer incidence data for the period 1999-2008 from the Georgia Comprehensive Cancer Registry with population data from the US Census and the Environmental Protection Agency's Toxics Release Inventory. We conducted cluster analyses and constructed Poisson regression models to assess DLBCL incidence as a function of mean distance to the toxic release sites.

RESULTS

In total, 3851 incident DLBCL cases occurred among adults residing in Georgia between 1999 and 2008. Significant focal clustering was observed around 57% of ethylene oxide sites, 5% of benzene sites, 9% of tetrachloroethylene sites, 7% of styrene sites, 10% of formaldehyde sites, 5% of trichloroethylene sites, and 10% of all release sites. Mean distance to sites was significantly associated with DLBCL risk for all chemicals.

CONCLUSIONS

Proximity to Toxics Release Inventory sites can be linked to increased DLBCL risk as assessed through focal clustering and Poisson regression, and confirmatory studies using geospatial mapping can aid in further specifying risk factors for DLBCL.

Occupation and Risk of Non-Hodgkin Lymphoma and Its Subtypes: A Pooled Analysis from the InterLymph Consortium

BACKGROUND

Various occupations have been associated with an elevated risk of non-Hodgkin lymphoma (NHL), but results have been inconsistent across studies.

OBJECTIVES

We investigated occupational risk of NHL and of four common NHL subtypes with particular focus on occupations of a priori interest.

METHODS

We conducted a pooled analysis of 10,046 cases and 12,025 controls from 10 NHL studies participating in the InterLymph Consortium. We harmonized the occupational coding using the 1968 International Standard Classification of Occupations (ISCO-1968) and grouped occupations previously associated with NHL into 25 a priori groups. Odds ratios (ORs) adjusted for center, age, and sex were determined for NHL overall and for the following four subtypes: diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL), and peripheral T-cell lymphoma (PTCL).

RESULTS

We confirmed previously reported positive associations between NHL and farming occupations [field crop/vegetable farm workers OR = 1.26; 95% confidence interval (CI): 1.05, 1.51; general farm workers OR = 1.19; 95% CI: 1.03, 1.37]; we also confirmed associations of NHL with specific occupations such as women's hairdressers (OR = 1.34; 95% CI: 1.02, 1.74), charworkers/cleaners (OR = 1.17; 95% CI: 1.01, 1.36), spray-painters (OR = 2.07; 95% CI: 1.30, 3.29), electrical wiremen (OR = 1.24; 95% CI: 1.00, 1.54), and carpenters (OR = 1.42; 95% CI: 1.04, 1.93). We observed subtype-specific associations for DLBCL and CLL/SLL in women's hairdressers and for DLBCL and PTCL in textile workers.

CONCLUSIONS

Our pooled analysis of 10 international studies adds to evidence suggesting that farming, hairdressing, and textile industry-related exposures may contribute to NHL risk. Associations with women's hairdresser and textile occupations may be specific for certain NHL subtypes.

CITATION

't Mannetje A, De Roos AJ, Boffetta P, Vermeulen R, Benke G, Fritschi L, Brennan P, Foretova L, Maynadié M, Becker N, Nieters A, Staines A, Campagna M, Chiu B, Clavel J, de Sanjose S, Hartge P, Holly EA, Bracci P, Linet MS, Monnereau A, Orsi L, Purdue MP, Rothman N, Lan Q, Kane E, Seniori Costantini A, Miligi L, Spinelli JJ, Zheng T, Cocco P, Kricker A. 2016. Occupation and risk of non-Hodgkin lymphoma and its subtypes: a pooled analysis from the InterLymph Consortium. Environ Health Perspect 124:396-405; http://dx.doi.org/10.1289/ehp.1409294.

Morbidity and Mortality in 7,684 Women According to Personal Hair Dye Use: The Copenhagen City Heart Study followed for 37 Years

Background

Permanent hair dye contains aromatic amines which are carcinogenic, and can cause allergic skin reactions. In the long term personal use of hair dye might therefore influence both morbidity and mortality.

Objectives

We tested the hypothesis that personal use of hair dye in women is associated with increased morbidity and mortality in the general population.

Methods

We included 7,684 women from the Copenhagen City Heart Study with information on the use of personal hair dye. We assessed the risk of cancer, skin diseases, other morbidities, and mortality during a median follow-up of 27 years (range 0–37).

Results

The multivariable adjusted hazard ratio for malignant melanoma in women with versus without personal use of hair dye was 2.07 (95% confidence interval 1.25–3.42). There was no increased risk of other cancer types. For other skin diseases and other major causes of morbidity we found no differences between the two groups, except for a minor excess of digestive diseases and increased risk of Parkinson’s disease among women using hair dye. Finally, we found no difference in all-cause mortality comparing women using personal hair dye or not. After correction for multiple comparisons, none of the results remained significant. However, in sensitivity analysis the excess risk of malignant melanoma remained increased with a hazard ratio of 2.58 (95%CI 1.33–5.03) among users of personal hair dye.

Conclusions

Personal use of hair dye does not have major influences on morbidity and mortality. Our finding of a 2-fold risk of malignant melanoma in women using hair dye is hypothesis generating.

CD19 chimeric antigen receptor (CD19 CAR)-redirected adoptive T-cell immunotherapy for the treatment of relapsed or refractory B-cell Non-Hodgkin's Lymphomas

Recovery rates for B-cell Non-Hodgkin's Lymphoma (NHL) are up to 70% with current standard-of-care treatments including rituximab (chimeric anti-CD20 monoclonal antibody) in combination with chemotherapy (R-CHOP). However, patients who do not respond to first-line treatment or develop resistance have a very poor prognosis. This signifies the need for the development of an optimal treatment approach for relapsed/refractory B-NHL. Novel CD19- chimeric antigen receptor (CAR) T-cell redirected immunotherapy is an attractive option for this subset of patients. Anti-CD19 CAR T-cell therapy has already had remarkable efficacy in various leukemias as well as encouraging outcomes in phase I clinical trials of relapsed/refractory NHL. In going forward with additional clinical trials, complementary treatments that may circumvent potential resistance mechanisms should be used alongside anti-CD19 T-cells in order to prevent relapse with resistant strains of disease. Some such supplementary tactics include conditioning with lymphodepletion agents, sensitizing with kinase inhibitors and Bcl-2 inhibitors, enhancing function with multispecific CAR T-cells and CD40 ligand-expressing CAR T-cells, and safeguarding with lymphoma stem cell-targeted treatments. A therapy regimen involving anti-CD19 CAR T-cells and one or more auxiliary treatments could dramatically improve prognoses for patients with relapsed/refractory B-cell NHL. This approach has the potential to revolutionize B-NHL salvage therapy in much the same way rituximab did for first-line treatments.

Lifestyle factors and risk of leukemia and non-Hodgkin's lymphoma: a case-control study

PURPOSE

Risk factors for leukemia and lymphomas in adults are largely unknown. This study was aimed at evaluating the association between lifestyle factors and the risk of hematological malignancies in an adult population.

METHODS

Data were drawn from a population-based case-control study carried out in Italy and included 294 cases (199 lymphoid and 95 myeloid) and 279 controls. Analyses were performed using standard multivariable logistic regression.

RESULTS

Hair dye use for at least 15 years was associated with a higher risk of lymphoid malignancies among females (OR 2.3, 95 % CI 1.0-4.9, p = 0.036, test for trend). Furthermore, a protective effect of a moderate to heavy tea consumption on the risk of myeloid malignancies was observed (OR 0.4, 95 % CI 0.2-0.9, p = 0.017). No association was found for the use of alcoholic beverages and tobacco smoking.

CONCLUSIONS

Our results confirm the potential carcinogenic effect of prolonged hair dye use observed in previous investigations. The excess risk could be explained by exposure to a higher concentration of toxic compounds in hair products used in the past. The protective effect of regular tea consumption observed in an area with a very high prevalence of black tea consumers deserves further investigation.

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

BACKGROUND

The etiology of mantle cell lymphoma (MCL), a distinctive subtype accounting for 2%-10% of all non-Hodgkin lymphoma, is not known.

METHODS

We investigated associations with self-reported medical history, lifestyle, family history, and occupational risk factors in a pooled analysis of 557 patients with MCL and 13766 controls from 13 case-control studies in Europe, North America, and Australia. Odds ratios (ORs) and 95% confidence intervals (CIs) associated with each exposure were examined using multivariate logistic regression models.

RESULTS

The median age of the MCL patients was 62 years and 76% were men. Risk of MCL was inversely associated with history of hay fever (OR = 0.63, 95% CI = 0.48 to 0.82), and the association was independent of other atopic diseases and allergies. A hematological malignancy among first-degree relatives was associated with a twofold increased risk of MCL (OR = 1.99, 95% CI = 1.39 to 2.84), which was stronger in men (OR = 2.21, 95% CI = 1.44 to 3.38) than women (OR = 1.61, 95% CI = 0.82 to 3.19). A modestly increased risk of MCL was also observed in association with ever having lived on a farm (OR = 1.40, 95% CI = 1.03 to 1.90). Unlike some other non-Hodgkin lymphoma subtypes, MCL risk was not statistically significantly associated with autoimmune disorders, tobacco smoking, alcohol intake, body mass index, or ultraviolet radiation.

CONCLUSIONS

The novel observations of a possible role for atopy and allergy and farm life in risk of MCL, together with confirmatory evidence of a familial link, suggest a multifactorial etiology of immune-related environmental exposures and genetic susceptibility. These findings provide guidance for future research in MCL etiology.

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.

Medical history, lifestyle, family history, and occupational risk factors for follicular lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Follicular lymphoma (FL) has been linked with cigarette smoking and, inconsistently, with other risk factors.

METHODS

We assessed associations of medical, hormonal, family history, lifestyle, and occupational factors with FL risk in 3530 cases and 22639 controls from 19 case-control studies in the InterLymph consortium. Age-, race/ethnicity-, sex- and study-adjusted odds ratios (ORs) and 95% confidence intervals (CIs) were estimated using logistic regression.

RESULTS

Most risk factors that were evaluated showed no association, except for a few modest or sex-specific relationships. FL risk was increased in persons: with a first-degree relative with non-Hodgkin lymphoma (OR = 1.99; 95% CI = 1.55 to 2.54); with greater body mass index as a young adult (OR = 1.15; 95% CI = 1.04 to 1.27 per 5 kg/m(2) increase); who worked as spray painters (OR = 2.66; 95% CI = 1.36 to 5.24); and among women with Sjögren syndrome (OR = 3.37; 95% CI = 1.23 to 9.19). Lower FL risks were observed in persons: with asthma, hay fever, and food allergy (ORs = 0.79-0.85); blood transfusions (OR = 0.78; 95% CI = 0.68 to 0.89); high recreational sun exposure (OR = 0.74; 95% CI = 0.65 to 0.86, fourth vs first quartile); who worked as bakers or millers (OR = 0.51; 95% CI = 0.28 to 0.93) or university/higher education teachers (OR = 0.58; 95% CI = 0.41 to 0.83). Elevated risks specific to women included current and longer duration of cigarette use, whereas reduced risks included current alcohol use, hay fever, and food allergies. Other factors, including other autoimmune diseases, eczema, hepatitis C virus seropositivity, hormonal drugs, hair dye use, sun exposure, and farming, were not associated with FL risk.

CONCLUSIONS

The few relationships observed provide clues suggesting a multifactorial etiology of FL but are limited in the extent to which they explain FL occurrence.

Medical history, lifestyle, family history, and occupational risk factors for marginal zone lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Marginal zone lymphoma (MZL), comprised of nodal, extranodal, and splenic subtypes, accounts for 5%-10% of non-Hodgkin lymphoma cases. A detailed evaluation of the independent effects of risk factors for MZL and its subtypes has not been conducted.

METHODS

Data were pooled from 1052 MZL cases (extranodal [EMZL] = 633, nodal [NMZL] = 157, splenic [SMZL] = 140) and 13766 controls from 12 case-control studies. Adjusted unconditional logistic regression was used to compute odds ratios (ORs) and 95% confidence intervals (CIs).

RESULTS

Novel findings for MZL subtypes include increased risk for B-cell activating autoimmune conditions (EMZL OR = 6.40, 95% CI = 4.24 to 9.68; NMZL OR = 7.80, 95% CI = 3.32 to 18.33; SMZL OR = 4.25, 95% CI = 1.49 to 12.14), hepatitis C virus seropositivity (EMZL OR = 5.29, 95% CI = 2.48 to 11.28), self-reported peptic ulcers (EMZL OR = 1.83, 95% CI = 1.35 to 2.49), asthma without other atopy (SMZL OR = 2.28, 95% CI = 1.23 to 4.23), family history of hematologic cancer (EMZL OR = 1.90, 95% CI = 1.37 to 2.62) and of non-Hodgkin lymphoma (NMZL OR = 2.82, 95% CI = 1.33 to 5.98), permanent hairdye use (SMZL OR = 6.59, 95% CI = 1.54 to 28.17), and occupation as a metalworker (NMZL OR = 3.56, 95% CI = 1.67 to 7.58). Reduced risks were observed with consumption of any alcohol (EMZL fourth quartile OR = 0.48, 95% CI = 0.28 to 0.82) and lower consumption of wine (NMZL first to third quartile ORs < 0.45) compared with nondrinkers, and occupation as a teacher (EMZL OR = 0.58, 95% CI = 0.37 to 0.88).

CONCLUSION

Our results provide new data suggesting etiologic heterogeneity across MZL subtypes although a common risk of MZL associated with B-cell activating autoimmune conditions was found.

Medical history, lifestyle, family history, and occupational risk factors for diffuse large B-cell lymphoma: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Although risk factors for diffuse large B-cell lymphoma (DLBCL) have been suggested, their independent effects, modification by sex, and association with anatomical sites are largely unknown.

METHODS

In a pooled analysis of 4667 cases and 22639 controls from 19 studies, we used stepwise logistic regression to identify the most parsimonious multivariate models for DLBCL overall, by sex, and for selected anatomical sites.

RESULTS

DLBCL was associated with B-cell activating autoimmune diseases (odds ratio [OR] = 2.36, 95% confidence interval [CI] = 1.80 to 3.09), hepatitis C virus seropositivity (OR = 2.02, 95% CI = 1.47 to 2.76), family history of non-Hodgkin lymphoma (OR = 1.95, 95% CI = 1.54 to 2.47), higher young adult body mass index (OR = 1.58, 95% CI = 1.12 to 2.23, for 35+ vs 18.5 to 22.4 kg/m(2)), higher recreational sun exposure (OR = 0.78, 95% CI = 0.69 to 0.89), any atopic disorder (OR = 0.82, 95% CI = 0.76 to 0.89), and higher socioeconomic status (OR = 0.86, 95% CI = 0.79 to 0.94). Additional risk factors for women were occupation as field crop/vegetable farm worker (OR = 1.78, 95% CI = 1.22 to 2.60), hairdresser (OR = 1.65, 95% CI = 1.12 to 2.41), and seamstress/embroider (OR = 1.49, 95% CI = 1.13 to 1.97), low adult body mass index (OR = 0.46, 95% CI = 0.29 to 0.74, for <18.5 vs 18.5 to 22.4 kg/m(2)), hormone replacement therapy started age at least 50 years (OR = 0.68, 95% CI = 0.52 to 0.88), and oral contraceptive use before 1970 (OR = 0.78, 95% CI = 0.62 to 1.00); and for men were occupation as material handling equipment operator (OR = 1.58, 95% CI = 1.02 to 2.44), lifetime alcohol consumption (OR = 0.57, 95% CI = 0.44 to 0.75, for >400 kg vs nondrinker), and previous blood transfusion (OR = 0.69, 95% CI = 0.57 to 0.83). Autoimmune disease, atopy, and family history of non-Hodgkin lymphoma showed similar associations across selected anatomical sites, whereas smoking was associated with central nervous system, testicular and cutaneous DLBCLs; inflammatory bowel disease was associated with gastrointestinal DLBCL; and farming and hair dye use were associated with mediastinal DLBCL.

CONCLUSION

Our results support a complex and multifactorial etiology for DLBCL with some variation in risk observed by sex and anatomical site.

Medical history, lifestyle, family history, and occupational risk factors for sporadic Burkitt lymphoma/leukemia: the Interlymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

The etiologic role of medical history, lifestyle, family history, and occupational risk factors in sporadic Burkitt lymphoma (BL) is unknown, but epidemiologic and clinical evidence suggests that risk factors may vary by age.

METHODS

We investigated risk factors for sporadic BL in 295 cases compared with 21818 controls in a pooled analysis of 18 case-control studies in the International Lymphoma Epidemiology Consortium (InterLymph). Cases were defined to include typical BL or Burkitt-like lymphoma. Odds ratios (ORs) and 95% confidence intervals (CIs) for associations were calculated separately for younger (<50 years) and older (≥ 50 years) BL using multivariate logistic regression.

RESULTS

Cases included 133 younger BL and 159 older BL (age was missing for three cases) and they were evenly split between typical BL (n = 147) and Burkitt-like lymphoma (n = 148). BL in younger participants was inversely associated with a history of allergy (OR = 0.58; 95% CI = 0.32 to 1.05), and positively associated with a history of eczema among individuals without other atopic conditions (OR = 2.54; 95% CI = 1.20 to 5.40), taller height (OR = 2.17; 95% CI = 1.08 to 4.36), and employment as a cleaner (OR = 3.49; 95% CI = 1.13 to 10.7). BL in older participants was associated with a history of hepatitis C virus seropositivity (OR = 4.19; 95% CI = 1.05 to 16.6) based on three exposed cases. Regardless of age, BL was inversely associated with alcohol consumption and positively associated with height.

CONCLUSIONS

Our data suggest that BL in younger and older adults may be etiologically distinct.

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.

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.

Racial differences in three major NHL subtypes: descriptive epidemiology

BACKGROUND

NHL (non-Hodgkin lymphoma) consists of over 60 subtypes, ranging from slow-growing to very aggressive. The three largest subtypes are DLBCL (diffuse large B-cell lymphoma), FL (follicular lymphoma), and CLL/SLL (chronic lymphocytic leukemia/small lymphocytic lymphoma). For each subtype, different racial groups have different presentations, etiologies, and prognosis patterns.

METHODS

SEER (Surveillance, Epidemiology, and End Results) data on DLBCL, FL, and CLL/SLL patients diagnosed between 1992 and 2010 were analyzed. Racial groups studied included NHW (non-Hispanic whites), HW (Hispanic whites), blacks, and API (Asians and Pacific Islanders). Patient characteristics, age-adjusted incidence rate, and survival were compared across races. Stratification and multivariate analysis were conducted.

RESULTS

There are significant racial differences for patients' characteristics, including gender, age at diagnosis, stage, lymph site, and age, and the patterns vary across subtypes. NHWs have the highest incidence rates for all three subtypes, followed by HWs (DLBCL and FL) and blacks (CLL/SLL). The dependence of the incidence rate on age and gender varies across subtypes. For all three subtypes, NHWs have the highest five-year relative survival rates, followed by HWs. When stratified by stage, racial difference is significant in multiple multivariate Cox regression analyses.

CONCLUSIONS

Racial differences exist among DLBCL, FL, and CLL/SLL patients in the U.S. in terms of characteristics, incidence, and survival. The patterns vary across subtypes. More data collection and analysis are needed to more comprehensively describe and interpret the across-race and subtype differences.

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.

Polymorphisms in DNA repair genes, hair dye use, and the risk of non-Hodgkin lymphoma

PURPOSE

Genetic polymorphisms in DNA repair genes and hair dye use may both have a role in the development of non-Hodgkin lymphoma (NHL). We aimed to examine the interaction between variants in DNA repair genes and hair dye use with risk of NHL in a population-based case-control study of Connecticut women.

METHODS

We examined 24 single nucleotide polymorphisms in 16 DNA repair genes among 518 NHL cases and 597 controls and evaluated the associations between hair dye use and risk of overall NHL and common NHL subtypes, stratified by genotype, using unconditional logistic regression.

RESULTS

Women who used hair dye before 1980 had a significantly increased risk of NHL, particularly for the follicular lymphoma (FL) subtype, but not for diffuse large B-cell lymphoma. The following genotypes in combination with hair dye use before 1980 were associated with FL risk: BRCA2 rs144848 AC+CC [odds ratio (OR) (95% confidence interval (CI)) 3.28(1.27-8.50)], WRN rs1346044 TT [OR(95% CI) 2.70(1.30-5.65)], XRCC3 rs861539 CT+TT [OR(95% CI) 2.76(1.32-5.77)], XRCC4 rs1805377 GG [OR(95% CI) 2.07(1.10-3.90)] and rs1056503 TT [OR(95% CI) 2.17(1.16-4.07)], ERCC1 rs3212961 CC [OR(95% CI) 1.93(1.00-3.72)], RAD23B rs1805329 CC [OR(95% CI) 2.28(1.12-4.64)], and MGMT rs12917 CC, rs2308321 AA, and rs2308327 AA genotypes [OR(95% CI) 1.96(1.06-3.63), 2.02(1.09-3.75), and 2.23(1.16-4.29), respectively]. In addition, a significant interaction with risk of overall NHL was observed between WRN rs1346044 and hair dye use before 1980 (p(interaction) = 0.032).

CONCLUSIONS

Our results indicated that genetic variation in DNA repair genes modifies susceptibility to NHL in relation to hair dye use, particularly for the FL subtype and in women who began using hair dye before 1980. Further studies are needed to confirm these observations.

Occupation and risk of lymphoid and myeloid leukaemia in the European Prospective Investigation into Cancer and Nutrition (EPIC)

OBJECTIVES

Established risk factors for leukaemia do not explain the majority of leukaemia cases. Previous studies have suggested the importance of occupation and related exposures in leukaemogenesis. We evaluated possible associations between job title and selected hazardous agents and leukaemia in the European Prospective Investigation into Cancer and Nutrition.

METHODS

The mean follow-up time for 241 465 subjects was 11.20 years (SD 2.42 years). During the follow-up period, 477 incident cases of myeloid and lymphoid leukaemia occurred. Data on 52 occupations considered a priori to be at high risk of developing cancer were collected through standardised questionnaires. Occupational exposures were estimated by linking the reported occupations to a job exposure matrix. Cox proportional hazard models were used to explore the association between occupation and related exposures and risk of leukaemia.

RESULTS

The risk of lymphoid leukaemia significantly increased for working in chemical laboratories (HR 8.35, 95% CI 1.58 to 44.24), while the risk of myeloid leukaemia increased for working in the shoe or other leather goods industry (HR 2.54, 95% CI 1.28 to 5.06). Exposure-specific analyses showed a non-significant increased risk of myeloid leukaemias for exposure to benzene (HR 1.15, 95% CI 0.75 to 1.40; HR=1.60, 95% CI 0.95 to 2.69 for the low and high exposure categories, respectively). This association was present both for acute and chronic myeloid leukaemia at high exposure levels. However, numbers were too small to reach statistical significance.

CONCLUSIONS

Our findings suggest a possible role of occupational exposures in the development of both lymphoid and myeloid leukaemia. Exposure to benzene seemed to be associated with both acute and chronic myeloid leukaemia.

A Review of Aspects of Oxidative Hair Dye Chemistry with Special Reference to N-Nitrosamine Formation

This review discusses a new aspect to the safety profile of oxidative hair dyes using data already in the public domain. These dyes contain secondary amines that are capable of forming potentially carcinogenic nitrosamine derivatives when exposed to atmospheric pollution. Numerous scientific articles confirm the existence of secondary amines in hair dyes (and their intermediates), the possibility of nitrosation by atmospheric NO_x of secondary amines to give the N-nitrosamines, and the significant safety risks on N-nitrosamines. It is believed that such nitrosamine derivatives should be investigated more fully in the interests of consumer safety.

Is there a true concern regarding the use of hair dye and malignancy development?: a review of the epidemiological evidence relating personal hair dye use to the risk of malignancy

Many advances in the cosmetic industry have increased our ability to enhance youth and beauty. Hair-coloring products are one such innovation. Over the past several decades, a significant amount of work has been dedicated to understanding the possible long-term side effects associated with hair-dye use, specifically looking at cancer risk. This paper describes the hair-coloring process, highlights the potentially carcinogenic ingredients in various hair-dying products, and reviews the epidemiological evidence relating personal hair-dye use to the risk of developing several types of malignancies.

Hematopathology in Sprague-Dawley rats following sub-chronic topical application of para-phenylenediamine

The aim of the present study was to analyze the hematological profile of male SD rats treated topically with aqueous solution of para-phenylenediamine (PPD), a component of almost all hair dye formulations. The rats were painted with different concentration of PPD (0, 1, 2 and 3 mg Kg(-1) Day(-1)) for 90 days and then sacrificed. The hematological profile indicated severe anemia characterized by significant (p < 0.05, 0.001) reduction of total RBC count (59%), packed cell volume (PCV, 50%) and haemoglobin level (70%) in the peripheral blood of PPD treated animals when compared to control group. The leucocytes profile exhibited an overall elevation of around twofold as compared to the control group with significant lymphocytosis (44.4%) and a higher percentage of blast cells (8.5%) as well as smudge (10.3%) and hairy cells (6.2%) in the peripheral blood of treated animals. Histopathological examination of spleen from treated rat's exhibit red pulp congestion, expansion of the germinal centre, hyperplasia of the membrane capsule and extensive accumulation of hemosidderin pigments in the red pulp of the spleen. Overall this study indicated an abnormal pathophysiological condition indicating adverse effect of PPD in the treated animal groups. The risk assessment of hair dye formulation needs to be reviewed in view of widespread usage of paraphenylenediamine in almost all hair dye formulation.

Current understanding of lifestyle and environmental factors and risk of non-hodgkin lymphoma: an epidemiological update

The incidence rates of non-Hodgkin lymphoma (NHL) have steadily increased over the last several decades in the United States, and the temporal trends in incidence can only be partially explained by the HIV epidemic. In 1992, an international workshop sponsored by the United States National Cancer Institute concluded that there was an “emerging epidemic” of NHL and emphasized the need to investigate the factors responsible for the increasing incidence of this disease. Over the past two decades, numerous epidemiological studies have examined the risk factors for NHL, particularly for putative environmental and lifestyle risk factors, and international consortia have been established in order to investigate rare exposures and NHL subtype-specific associations. While few consistent risk factors for NHL aside from immunosuppression and certain infectious agents have emerged, suggestive associations with several lifestyle and environmental factors have been reported in epidemiologic studies. Further, increasing evidence has suggested that the effects of these and other exposures may be limited to or stronger for particular NHL subtypes. This paper examines the progress that has been made over the last twenty years in elucidating the etiology of NHL, with a primary emphasis on lifestyle factors and environmental exposures.