Project description:BackgroundThere are several suspected environmental risk factors for non-Hodgkin lymphoma (NHL). The associations between NHL and environmental chemical exposures have typically been evaluated for individual chemicals (i.e., one-by-one).ObjectivesWe determined the association between a mixture of 27 correlated chemicals measured in house dust and NHL risk.MethodsWe conducted a population-based case-control study of NHL in four National Cancer Institute-Surveillance, Epidemiology, and End Results centers--Detroit, Michigan; Iowa; Los Angeles County, California; and Seattle, Washington--from 1998 to 2000. We used weighted quantile sum (WQS) regression to model the association of a mixture of chemicals and risk of NHL. The WQS index was a sum of weighted quartiles for 5 polychlorinated biphenyls (PCBs), 7 polycyclic aromatic hydrocarbons (PAHs), and 15 pesticides. We estimated chemical mixture weights and effects for study sites combined and for each site individually, and also for histologic subtypes of NHL.ResultsThe WQS index was statistically significantly associated with NHL overall [odds ratio (OR) = 1.30; 95% CI: 1.08, 1.56; p = 0.006; for one quartile increase] and in the study sites of Detroit (OR = 1.71; 95% CI: 1.02, 2.92; p = 0.045), Los Angeles (OR = 1.44; 95% CI: 1.00, 2.08; p = 0.049), and Iowa (OR = 1.76; 95% CI: 1.23, 2.53; p = 0.002). The index was marginally statistically significant in Seattle (OR = 1.39; 95% CI: 0.97, 1.99; p = 0.071). The most highly weighted chemicals for predicting risk overall were PCB congener 180 and propoxur. Highly weighted chemicals varied by study site; PCBs were more highly weighted in Detroit, and pesticides were more highly weighted in Iowa.ConclusionsAn index of chemical mixtures was significantly associated with NHL. Our results show the importance of evaluating chemical mixtures when studying cancer risk.
Project description:BackgroundNon-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.MethodsWe 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).ResultsRisks 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.ConclusionsUsing 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.
Project description:<p>Within the framework of the International Lymphoma Epidemiology Consortium (InterLymph) Consortium and NCI-sponsored Cohort Consortium, investigators from 22 studies came together to conduct a genome-wide association study (GWAS) of non-Hodgkin lymphoma (NHL). The goal of the study was to identify common genetic variants associated with the risk of NHL. As described previously (Berndt SI et al., Nature Genetics, 2013, PMID: <a href="http://www.ncbi.nlm.nih.gov/pubmed/?term=23770605">23770605</a> ), cases and controls from 22 studies, including nine prospective cohort studies, eight population-based case-control studies, and five clinic or hospital-based case-control studies were included in this effort. Cases of NHL were ascertained from cancer registries, clinics or hospitals, or through self-report verified by medical and pathology reports. The phenotype information for all NHL cases was reviewed centrally at the InterLymph Data Coordinating Center and harmonized according to the hierarchical classification proposed by the InterLymph Pathology Working Group based on the World Health Organization (WHO) classification (2008). Controls were frequency matched to cases on age and gender by study, and the study was limited to subjects of European ancestry. Participants were genotyped using the Illumina Omni Express.</p> <p><b>The NCI Non-Hodgkin Lymphoma GWAS is utilized in the following dbGaP sub-studies.</b> To view genotypes and derived variables collected in these sub-studies, please click on the following sub-studies below or in the "Sub-studies" box located on the right hand side of this top-level study page <a href="study.cgi?study_id=phs000801">phs000801</a> NCI Non-Hodgkin Lymphoma GWAS. <ul> <li><a href="study.cgi?study_id=phs000802">phs000802</a> NCI Non-Hodgkin Lymphoma GWAS: CLL</li> <li><a href="study.cgi?study_id=phs000818">phs000818</a> NCI Non-Hodgkin Lymphoma GWAS: Controls</li> <li><a href="study.cgi?study_id=phs000889">phs000889</a> NCI Non-Hodgkin Lymphoma GWAS: DLBCL</li> <li><a href="study.cgi?study_id=phs000890">phs000890</a> NCI Non-Hodgkin Lymphoma GWAS: FL</li> <li><a href="study.cgi?study_id=phs000891">phs000891</a> NCI Non-Hodgkin Lymphoma GWAS: MZL</li> </ul> </p>
Project description:Classical Hodgkin lymphoma (cHL) is characterized by nearly universal genetic alterations in 9p24.1, resulting in constitutive expression of PD-1 ligands. This likely underlies the unique sensitivity of cHL to PD-1 blockade, with response rates of ∼70% in relapsed/refractory disease. There are now numerous clinical trials testing PD-1 inhibitors in earlier stages of treatment and in combination with many other therapies. In general, non-Hodgkin lymphomas (NHLs) do not display a high frequency of 9p24.1 alterations and do not share cHL's vulnerability to PD-1 blockade. However, a few entities have genetic or immunologic features that may predict sensitivity to immune checkpoint blockade. These include primary mediastinal B cell lymphoma, primary central nervous system lymphoma, and primary testicular lymphoma, which harbor frequent alterations in 9p24.1, as well as Epstein Barr virus (EBV)-infected lymphomas, where EBV infection leads to increased PD-L1 expression. Although these subtypes may be specifically vulnerable to PD-1 blockade, the majority of NHLs appear to be minimally sensitive to PD-1 blockade monotherapy. Current investigations in NHL are therefore focusing on targeting other checkpoints or studying PD-1-based combination therapy. Looking forward, additional insight into the most common mechanisms of resistance to immune checkpoint inhibitors will be important to guide rational clinical trial design. In this review, we describe the biological basis for checkpoint blockade in cHL and NHL and summarize the clinical data generated to date. Guided by our rapidly evolving understanding of the pathobiology of various lymphoma subtypes, we are hopeful that the role of checkpoint inhibitors in lymphoma treatment will continue to grow.
Project description:Reed-Sternberg cells (RSCs) are hallmarks of classic Hodgkin lymphoma (cHL). However, cells with a similar morphology and immunophenotype, so-called Reed-Sternberg-like cells (RSLCs), are occasionally seen in both B cell and T cell non-Hodgkin Lymphomas (NHLs). In NHLs, RSLCs are usually present as scattered elements or in small clusters, and the typical background microenviroment of cHL is usually absent. Nevertheless, in NHLs, the phenotype of RSLCs is very similar to typical RSCs, staining positive for CD30 and EBV, and often for B cell lineage markers, and negative for CD45/LCA. Due to different therapeutic approaches and prognostication, it is mandatory to distinguish between cHL and NHLs. Herein, NHL types in which RSLCs can be detected along with clinicopathological correlation are described. Moreover, the main helpful clues in the differential diagnosis with cHL are summarized.
Project description:MicroRNAs (miRNAs), small non-coding RNAs that regulate gene expression by binding to the 3'-UTR of their target genes, can act as oncogenes or tumor suppressors. Recently, other types of non-coding RNAs-piwiRNAs and long non-coding RNAs-have also been identified. Hodgkin lymphoma (HL) is a B cell origin disease characterized by the presence of only 1% of tumor cells, known as Hodgkin and Reed-Stenberg (HRS) cells, which interact with the microenvironment to evade apoptosis. Several studies have reported specific miRNA signatures that can differentiate HL lymph nodes from reactive lymph nodes, identify histologic groups within classical HL, and distinguish HRS cells from germinal center B cells. Moreover, some signatures are associated with survival or response to chemotherapy. Most of the miRNAs in the signatures regulate genes related to apoptosis, cell cycle arrest, or signaling pathways. Here we review findings on miRNAs in HL, as well as on other non-coding RNAs.
Project description:INTRODUCTION: Despite decades of intensive research, Non-Hodgkin Lymphoma (NHL) remains poorly understood and is largely incurable. NHL is a heterogeneous group of malignancies with multiple subtypes, each of which has distinct morphologic, immunophenotypic, and clinical features. Identifying the risk factors for NHL may improve our understanding of the underlying biological mechanisms and have an impact on clinical practice. AREAS COVERED: This article provides a review of several aspects of NHL, including epidemiology and subtype classification, clinical, environmental, genetic, and genomic risk factors identified for etiology and prognosis, and available statistical and bioinformatics tools for identification of genetic and genomic risk factors from the analysis of high-throughput studies. EXPERT OPINION: Multiple clinical and environmental risk factors have been identified. However, they have failed to provide practically effective prediction. Genetic and genomic risk factors identified from high-throughput studies have suffered a lack of reproducibility. The identification of genetic/genomic risk factors demands innovative statistical and bioinformatics tools. Although multiple analysis methods have been developed, there is still room for improvement. There is a critical need for well-designed, prospective, large-scale pangenomic studies.
Project description:ObjectivesSurvivors after pediatric Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) are with lifetime risk for second primary malignancy (SPM). This necessitates a thorough analysis to better understand the potential long-term health implications for these individuals.MethodsWe used a US-wide population-based cancer registry data to quantify the SPM risk and identify its incidence patterns among pediatric lymphoma patients.ResultsWe observed 4.74-fold (95% CI 4.27-5.25) and 3.40-fold (95% CI 2.78-4.10) increased risks of SPM in survivors after pediatric HL and NHL, respectively. Through over 40 years' follow-up, the cumulative incidence of SPM for pediatric lymphoma was persistently increasing, and here we firstly report the high 40-year cumulative incidence rates of SPM, 22.2% for HL and 12.6% for NHL, suggesting that SPM accounts for a great proportion of deaths among survivors. Of 6805 pediatric lymphomas, 462 (6.36%) developed a SPM, especially second breast and thyroid cancer, followed by hematologic neoplasms including leukemia and NHL. The competing risk analysis demonstrated gender, lymphoma subtype and radiotherapy were significantly associated with SPM. Different risk patterns of SPM were identified between pediatric HL and NHL. Chemotherapy accelerated SPM development but did not increase its incidence risk.ConclusionOverall, patients after pediatric lymphoma can be with high lifetime risk of SPM, and more attention should be paid to SPM-related signs for early detection and intervention.
Project description:FDG-PET scanning has a central role in lymphoma staging and response assessment. There is a growing body of evidence that PET response assessment during and after initial systemic therapy can provide useful prognostic information, and PET response has an evolving role in guiding patient care. This review provides a perspective on the role of PET response assessment for individualised management of patients with the most common aggressive lymphomas, Hodgkin lymphoma and diffuse large B-cell lymphoma.
Project description:BackgroundEpigenetic inactivation of tumor suppressor genes (TSG) by promoter CpG island hypermethylation is a hallmark of cancer. To assay its extent in human lymphoma, methylation of 24 TSG was analyzed in lymphoma-derived cell lines as well as in patient samples.MethodsWe screened for TSG methylation using methylation-specific multiplex ligation-dependent probe amplification (MS-MLPA) in 40 lymphoma-derived cell lines representing anaplastic large cell lymphoma, Burkitt lymphoma (BL), diffuse large B-cell lymphoma (DLBCL), follicular lymphoma (FL), Hodgkin lymphoma and mantle cell lymphoma (MCL) as well as in 50 primary lymphoma samples. The methylation status of differentially methylated CD44 was verified by methylation-specific PCR and bisulfite sequencing. Gene expression of CD44 and its reactivation by DNA demethylation was determined by quantitative real-time PCR and on the protein level by flow cytometry. Induction of apoptosis by anti-CD44 antibody was analyzed by annexin-V/PI staining and flow cytometry.ResultsOn average 8 ± 2.8 of 24 TSG were methylated per lymphoma cell line and 2.4 ± 2 of 24 TSG in primary lymphomas, whereas 0/24 TSG were methylated in tonsils and blood mononuclear cells from healthy donors. Notably, we identified that CD44 was hypermethylated and transcriptionally silenced in all BL and most FL and DLBCL cell lines, but was usually unmethylated and expressed in MCL cell lines. Concordant results were obtained from primary lymphoma material: CD44 was not methylated in MCL patients (0/11) whereas CD44 was frequently hypermethylated in BL patients (18/29). In cell lines with CD44 hypermethylation, expression was re-inducible at mRNA and protein levels by treatment with the DNA demethylating agent 5-Aza-2'-deoxycytidine, confirming epigenetic regulation of CD44. CD44 ligation assays with a monoclonal anti-CD44 antibody showed that CD44 can mediate apoptosis in CD44+ lymphoma cells. CD44 hypermethylated, CD44- lymphoma cell lines were consistently resistant towards anti-CD44 induced apoptosis.ConclusionOur data show that CD44 is epigenetically regulated in lymphoma and undergoes de novo methylation in distinct lymphoma subtypes like BL. Thus CD44 may be a promising new epigenetic marker for diagnosis and a potential therapeutic target for the treatment of specific lymphoma subtypes.