H2AFX encodes a histone variant involved in signaling sites of DNA damage and recruiting repair factors. Genetic variants in H2AFX may influence risk of non-Hodgkin lymphoma (NHL), a heterogeneous group of lymphoid tumors that are characterized by chromosomal translocations. We previously reported that rs2509049, a common variant in the promoter of H2AFX, was associated with risk for NHL in the British Columbia population. Here we report results for 13 single nucleotide polymorphisms (SNPs) in 100 Kb surrounding H2AFX in an expanded collection of 568 NHL cases and 547 controls. After correction for multiple testing, significant associations were present for mantle cell lymphoma (p=0.007 for rs604714) and all B-cell lymphomas (p=0.046 for rs2509049). Strong linkage disequilibrium in the 5 Kb upstream of H2AFX limited the ability to determine which specific SNP (rs2509049, rs7759, rs8551, rs643788, rs604714, or rs603826), if any, was responsible. There was a significant interaction between sex and rs2509049 in the all B-cell lymphomas group (p=0.002); a sex-stratified analysis revealed that the association was confined to females (p=0.001). Neither the overall nor the female-specific association with rs2509049 was replicated in any of four independent NHL sample sets. Meta-analysis of all five study populations (3,882 B-cell NHL cases and 3,718 controls) supported a weak association with B-cell lymphoma (OR=0.92, 95% CI=0.86-0.99, p=0.034), although this association was not significant after exclusion of the British Columbia data. Further research into the potential sex-specificity of the H2AFX-NHL association may identify a subset of NHL cases that are influenced by genotype at this locus.
Prospective studies of lifestyle and non-Hodgkin lymphoma (NHL) are conflicting, and some are inconsistent with case-control studies. The Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial was used to evaluate risk of NHL and its subtypes in association with anthropometric factors, smoking, and alcohol consumption in a prospective cohort study. Lifestyle was assessed via questionnaire among 142,982 male and female participants aged 55–74 years enrolled in the PLCO Trial during 1993–2001. Hazard ratios and 95% confidence intervals were calculated using Cox proportional hazards regression. During 1,201,074 person-years of follow-up through 2006, 1,264 histologically confirmed NHL cases were identified. Higher body mass index (BMI; weight (kg)/height (m)2) at ages 20 and 50 years and at baseline was associated with increased NHL risk (Ptrend < 0.01 for all; e.g., for baseline BMI ≥30 vs. 18.5–24.9, hazard ratio = 1.32, 95% confidence interval: 1.13, 1.54). Smoking was not associated with NHL overall but was inversely associated with follicular lymphoma (ever smoking vs. never: hazard ratio = 0.62, 95% confidence interval: 0.45, 0.85). Alcohol consumption was unrelated to NHL (drinks/week: Ptrend = 0.187). These data support previous studies suggesting that BMI is positively associated with NHL, show an inverse association between smoking and follicular lymphoma (perhaps due to residual confounding), and do not support a causal association between alcohol and NHL.
alcoholic beverages; anthropometry; body height; body mass index; body weight; life style; lymphoma; non-Hodgkin; smoking
Both LMO2 mRNA and protein expression in diffuse large B-cell lymphoma (DLBCL) have been associated with superior survival; however, a role for germline genetic variation in LMO2 has not been previously reported. Immunohistochemistry (IHC) for LMO2 was conducted on tumor tissue from diagnostic biopsies, and 20 tag single nucleotide polymorphisms (SNPs) from LMO2 were genotyped from germline DNA. LMO2 IHC positivity was associated with superior survival (HR=0.55; 95% CI 0.31–0.97). Four LMO2 SNPs (rs10836127, rs941940, rs750781, rs1885524) were associated with survival after adjusting for LMO2 IHC and clinical factors (p<0.05), and one of these SNPs (rs941940) was also associated with IHC positivity (p=0.02). Compared to a model with clinical factors only (c-statistic=0.676), adding the 4 SNPs (c-statistic=0.751) or LMO2 IHC (c-statistic=0.691) increased the predictive ability of the model, while inclusion of all 3 factors (c-statistic=0.754) did not meaningfully add predictive ability above a model with clinical factors and the 4 SNPs. In conclusion, germline genetic variation in LMO2 was associated with DLBCL prognosis and provided slightly stronger predictive ability relative to LMO2 IHC status.
Diffuse large B-cell lymphoma; LMO2; prognosis; single nucleotide polymorphisms
Reasons for higher incidence of lymphoid neoplasms among men than women are unknown. Because female sex hormones have immunomodulatory effects, reproductive factors and exogenous hormone use may affect risk for lymphoid malignancies. Previous epidemiologic studies on this topic have yielded conflicting results. Within the National Institutes of Health-AARP Diet and Health Study cohort, we prospectively analyzed detailed, questionnaire-derived information on menstrual and reproductive factors and use of oral contraceptives and menopausal hormone therapy among 134,074 US women. Using multivariable proportional hazards regression models, we estimated relative risks (RRs) for 85 plasma cell neoplasms and 417 non-Hodgkin lymphomas (NHLs) identified during follow-up from 1996-2002. We observed no statistically significant associations between plasma cell neoplasms, NHL, or the three most common NHL subtypes and age at menarche, parity, age at first birth, oral contraceptive use, or menopausal status at baseline. For menopausal hormone therapy use, overall associations between NHL and unopposed estrogen and estrogen plus progestin were null, with the potential exception of an inverse association (RR=0.49, 95% CI, 0.25-0.96) between use of unopposed estrogen and diffuse large B-cell lymphoma (DLBCL), the most common NHL subtype, among women with a hysterectomy. These data do not support an important role for reproductive factors or exogenous hormones in modulating lymphomagenesis.
Aromatic amine components in hair dyes, and polymorphisms in genes that encode enzymes responsible for hair dye metabolism, may be related to bladder cancer risk. We evaluated the association between hair dye use and bladder cancer risk and effect modification by NAT1, NAT2, GSTM1, and GSTT1 genotypes in a population-based case-control study of 1,193 incident cases and 1,418 controls from Maine, Vermont, and New Hampshire enrolled between 2001 and 2004. Individuals were interviewed in person using a computer-assisted personal interview to assess hair dye use and information on potential confounders and effect modifiers. No overall association between age at first use, year of first use, type of product, color, duration, or number of applications of hair dyes and bladder cancer among women or men was apparent but increased risks were observed in certain subgroups. Women who used permanent dyes and had a college degree, a marker of socioeconomic status, had an increased risk of bladder cancer (OR=3.3, 95% CI: 1.2, 8.9). Among these women, we found an increased risk of bladder cancer among exclusive users of permanent hair dyes who had NAT2 slow acetylation phenotype (OR=7.3, 95% CI: 1.6, 32.6) compared to never users of dye with NAT2 rapid/intermediate acetylation phenotype. While we found no relation between hair dye use and bladder cancer risk in women overall, we detected evidence of associations and gene-environment interaction with permanent hair dye use; however, this was limited to educated women. These results need confirmation with larger numbers, requiring pooling data from multiple studies.
hair dyes; bladder; cancer; aromatic amines; genetics
The t(14;18) chromosomal translocation is the most common cytogenetic abnormality in NHL, occurring in 70–90% of follicular lymphomas (FL) and 30–50% of diffuse large B-cell lymphomas (DLBCL). Previous t(14;18)-NHL studies have not evaluated risk factors for NHL defined by both t(14;18) status and histology. In this population-based case-control study, t(14;18) status was determined in DLBCL cases using fluorescence in situ hybridization on paraffin-embedded tumor sections. Polytomous logistic regression was used to evaluate the association between a wide variety of exposures and t(14;18)-positive (N=109) and −negative DLBCL (N=125) and FL (N=318), adjusting for sex, age, race and study center. Taller height, more lifetime surgeries, and PCB180 exposure were associated with t(14;18)-positivity. Taller individuals (3rd tertile vs. 1st tertile) had elevated risks of t(14;18)-positive DLBCL [odds ratio (OR)=1.8, 95% confidence interval (CI) 1.1–3.0] and FL (OR=1.4, 95%CI 1.0–1.9) but not t(14;18)-negative DLBCL. Similar patterns were seen for individuals with more lifetime surgeries [13+ versus 0–12 surgeries; t(14;18)-positive DLBCL OR=1.4, 95%CI 0.7–2.7; FL OR=1.6, 95%CI 1.1–2.5] and individuals exposed to PCB180 greater than 20.8 ng/g [t(14;18)-positive DLBCL OR=1.3, 95%CI 0.6–2.9; FL OR=1.7, 95%CI 1.0–2.8]. In contrast, termite treatment and high alpha-chlordane levels were associated with t(14;18)-negative DLBCL only, suggesting that these exposures do not act through t(14;18). Our findings suggest that putative associations between NHL and height, surgeries, and PCB180 may be t(14;18)-mediated and provide support for case-subtyping based on molecular and histologic subtypes. Future efforts should focus on pooling data to confirm and extend previous research on risk factors for t(14;18)-NHL subtypes.
lymphoma; non-Hodgkin; case–control studies; translocation; follicular lymphoma; diffuse large B-cell lymphoma; etiology
The balance between Th1 and Th2 activity is critical in lymphoid cell development and differentiation. Immune dysfunction underlies lymphomagenesis, so an alteration in the regulation of key Th1/Th2 cytokines may lead to the development of non-Hodgkin lymphoma (NHL). To study the impact of polymorphism in Th1/Th2 cytokines on NHL risk, we analyzed 145 tag single nucleotide polymorphisms (SNPs) in 17 Th1/Th2 cytokine and related genes in three population-based case-control studies (1,946 cases and 1,808 controls). Logistic regression was used to compute odds ratios (OR) for NHL and four major NHL subtypes in relation to tag SNP genotypes and haplotypes. A gene-based analysis adjusting for the number of tag SNPs genotyped in each gene showed significant associations with risk of NHL combined and one or more NHL subtypes for Th1 (IL12A and IL12RB1) and Th2 (IL4, IL10RB, and IL18) genes. The strongest association was for IL12A rs485497, which plays a central role in bridging the cellular and humoral pathways of innate resistance and antigen-specific adaptive immune responses (allele risk OR=1.17; P(trend)=0.00099). This SNP was also associated specifically with risk of follicular lymphoma (allele risk OR=1.26; P(trend)=0.0012). These findings suggest that genetic variation in Th1/Th2 cytokine genes may contribute to lymphomagenesis.
Non-Hodgkin lymphoma; single nucleotide polymorphisms; immunogenetics; case-control study
Autoimmunity is clearly linked with hematologic malignancies, but less is known about autoimmunity and alimentary tract cancer risk, despite the specific targeting of alimentary organs and tissues by several autoimmune diseases. We therefore conducted the first systematic evaluation of a broad range of specific autoimmune diseases and risk for subsequent alimentary tract cancer.
Based on 4,501,578 U.S. male Veterans, we identified 96,277 men who developed alimentary tract cancer during up to 26.2 years of follow-up. Using Poisson regression methods we calculated relative risks (RR) and 95% confidence intervals.
A history of autoimmune disease with localized alimentary tract effects generally increased cancer risks in the organ(s) affected by the autoimmune disease, such as primary biliary cirrhosis and liver cancer (RR=6.01, 4.76–7.57); pernicious anemia and stomach cancer (RR=3.17, 2.47–4.07); and ulcerative colitis and small intestine, colon, and rectal cancers (RR=2.53, 1.05–6.11; RR=2.06, 1.70–2.48; and RR=2.07, 1.62–2.64, respectively). In addition, a history of celiac disease, reactive arthritis (Reiter’s disease), localized scleroderma, and systemic sclerosis all were associated significantly with increased risk of esophageal cancer (RR=1.86–2.86). Autoimmune diseases without localized alimentary tract effects generally were not associated with alimentary tract cancer risk, with the exception of decreased risk for multiple alimentary tract cancers associated with a history of multiple sclerosis.
Our findings support the importance of localized inflammation in alimentary tract carcinogenesis. Future research is needed to confirm our findings and improve our understanding of underlying mechanisms by which autoimmune diseases contribute to alimentary tract carcinogenesis.
Alimentary; gastrointestinal; autoimmune disease; inflammation; cancer
Genetic variation in immune-related genes may play a role in the development of non-Hodgkin lymphoma (NHL). To test the hypothesis that innate immunity polymorphisms may be associated with NHL risk, we genotyped 144 tag single nucleotide polymorphisms (tagSNPs) capturing common genetic variation within 12 innate immunity gene regions in three independent population-based case-control studies (1946 cases and 1808 controls). Gene-based analyses found IL1RN to be associated with NHL risk (minP = 0.03); specifically, IL1RN rs2637988 was associated with an increased risk of NHL (per-allele odds ratio = 1.15, 95% confidence interval = 1.05 – 1.27; ptrend = 0.003), which was consistent across study, subtype, and gender. FCGR2A was also associated with a decreased risk of the follicular lymphoma NHL subtype (minP = 0.03). Our findings suggest that genetic variation in IL1RN and FCGR2A may play a role in lymphomagenesis. Given that conflicting results have been reported regarding the association between IL1RN SNPs and NHL risk, a larger number of innate immunity genes with sufficient genomic coverage should be evaluated systematically across many studies.
non-Hodgkin lymphoma; immune; innate immunity; genetic variation; single nucleotide polymorphisms
Previous studies have shown increased risks of second malignancies after non-Hodgkin's lymphoma (NHL) and chronic lymphocytic leukemia (CLL); however, no earlier investigation has quantified differences in risk of new malignancy by lymphoma subtype.
Patients and Methods
We evaluated second cancer and leukemia risks among 43,145 1-year survivors of CLL/small lymphocytic lymphoma (SLL), diffuse large B-cell lymphoma (DLBCL), or follicular lymphoma (FL) from 11 Surveillance, Epidemiology, and End Results (SEER) population-based registries during 1992 to 2006.
Among patients without HIV/AIDS–related lymphoma, lung cancer risks were significantly elevated after CLL/SLL and FL but not after DLBCL (standardized incidence ratio [SIR], CLL/SLL = 1.42, FL = 1.28, DLBCL = 1.00; Poisson regression P for difference among subtypes, PDiff = .001). A similar pattern was observed for risk of cutaneous melanoma (SIR: CLL/SLL = 1.92, FL = 1.60, DLBCL = 1.06; PDiff = .004). Acute nonlymphocytic leukemia risks were significantly elevated after FL and DLBCL, particularly among patients receiving initial chemotherapy, but not after CLL/SLL (SIR: CLL/SLL = 1.13, FL = 5.96, DLBCL = 4.96; PDiff < .001). Patients with HIV/AIDS–related lymphoma (n = 932) were predominantly diagnosed with DLBCL and had significantly and substantially elevated risks for second anal cancer (SIR = 120.50) and Kaposi's sarcoma (SIR = 138.90).
Our findings suggest that differing immunologic alterations, treatments (eg, alkylating agent chemotherapy), genetic susceptibilities, and other risk factors (eg, viral infections, tobacco use) among lymphoma subtypes contribute to the patterns of second malignancy risk. Elucidating these patterns may provide etiologic clues to lymphoma as well as to the second malignancies.
To assess the risk and identify risk factors of Hodgkin lymphoma (HL) in solid organ transplant recipients. Prior research has been limited by the rarity of HL and the requirement for extended follow-up after transplantation.
Using data from the Scientific Registry of Transplant Recipients (SRTR), we conducted a retrospective cohort study of U.S. solid organ transplant recipients (1997–2007). We estimated hazard ratios (HRs) for HL risk factors using proportional hazards regression. Standardized incidence ratios (SIRs) compared HL risk in the transplant cohort with the general population.
The cohort included 283,190 transplant recipients (average follow-up 3.7 years after transplantation). Based on 73 cases, HL risk factors included male gender (HR 2.1, 95%CI 1.2–3.7), young age (4.0, 2.3–6.8), and EBV seronegativity at the time of transplantation (3.1, 1.2–8.1). Among tumors with EBV status information, 79% were EBV positive, including all tumors in recipients who were initially seronegative. Overall, HL risk was higher than in the general population (SIR 2.2) and increased monotonically over time following transplantation (SIR 4.1 at 8–10 years post-transplant). Excess HL risk was especially high following heart and/or lung transplantation (SIR 3.2).
HL is a late complication of solid organ transplantation. The high HL risk in recipients who were young or EBV seronegative at the time of transplant, and the fact that most HL tumors were EBV positive, highlight the role of primary EBV infection and poor immune control of this virus. The occurrence of HL may rise with improved long-term survival in transplant recipients.
Hodgkin lymphoma; transplantation; Epstein-Barr virus; United States
Genetic variation in the 6p21 chromosomal region, including human leukocyte antigen (HLA) genes and tumor necrosis factor (TNF), has been linked to both etiology and clinical outcomes of lymphomas. We estimated the effects of HLA class I (A, B, and C), class II DRB1 alleles, and the ancestral haplotype (AH) 8.1 (HLAA*01-B*08-DRB1*03-TNF-308A) on overall survival (OS) among patients with diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma (FL) in a population-based study of non-Hodgkin lymphoma. During a median followup of 89 months, 31% (52 of 166) DLBCL and 28% (46 of 165) FL patients died. Using multivariate Cox regression models, we observed statistically significant associations between genetic variants and survival: HLA-Cw*07:01 was associated with poorer OS among DLBCL patients (Hazard ratio [HR] = 1.76, 95% confidence interval [CI] = 1.01–3.05); HLA-A*01:01 was associated with poorer OS (HR = 2.23, 95% CI = 1.24–4.01), and HLA-DRB1*13 (HR = 0.12, 95% CI = 0.02–0.90) and HLA-B Bw4 (HR = 0.36, 95% CI = 0.20–0.63) with better OS among FL patients. These results support a role for HLA in the prognosis of DLBCL and FL and represent a promising class of prognostic factors that warrants further evaluation.
human leukocyte antigen; tumor necrosis factor; diffuse large B-cell lymphoma; follicular lymphoma; survival
Gene expression profiling studies have distinguished diffuse large B-cell lymphomas (DLBCLs) by cell of origin, with distinct pathogenetic mechanisms and prognosis. We attempted to identify DLBCL molecular subtypes in an epidemiologic study of 214 DLBCL patients diagnosed during 1998-2000 with archival tissues to investigate etiology. Immunohistochemical staining for CD10, BCL6, LMO2, MUM1/IRF4, and BCL2 and fluorescence in situ hybridization for t(14;18) were conducted, with ≥93% blinded duplicate agreement. CD10, LMO2, and BCL2 expression was similar to previous reports (32%, 44%, and 44% of DLBCLs, respectively), but BCL6 and MUM1/IRF4 expression was lower than expected (29% and 5%, respectively). We classified 112/214 (52%) cases as germinal center B-cell-like DLBCL (GCB-DLBCL; Hans et al., Blood 2004; CD10+ or CD10-/BCL6+/MUM1-), with no difference in prognosis compared with non-GCB-DLBCL (Cox regression, P=0.48). Comparing other GCB correlates, LMO2 expression and t(14;18) were more common but not exclusive to GCB-DLBCL as defined in our study, whereas BCL2 expression did not differ between DLBCL molecular subtypes. We could not confidently identify patients with GCB-DLBCL using these immunohistochemistry-based markers on archival tissues.
diffuse large B-cell lymphoma; germinal center; molecular epidemiology; immunohistochemistry
Exploring spatial-temporal patterns of disease incidence through cluster analysis identifies areas of significantly elevated or decreased risk, providing potential clues about disease risk factors. Little is known about the etiology of non-Hodgkin lymphoma (NHL), or the latency period that might be relevant for environmental exposures, and there are no published spatial-temporal cluster studies of NHL.
We conducted a population-based case-control study of NHL in four National Cancer Institute (NCI)-Surveillance, Epidemiology, and End Results (SEER) centers: Detroit, Iowa, Los Angeles, and Seattle during 1998-2000. Using 20-year residential histories, we used generalized additive models adjusted for known risk factors to model spatially the probability that an individual had NHL and to identify clusters of elevated or decreased NHL risk. We evaluated models at five different time periods to explore the presence of clusters in a time frame of etiologic relevance.
The best model fit was for residential locations 20 years prior to diagnosis in Detroit, Iowa, and Los Angeles. We found statistically significant areas of elevated risk of NHL in three of the four study areas (Detroit, Iowa, and Los Angeles) at a lag time of 20 years. The two areas of significantly elevated risk in the Los Angeles study area were detected only at a time lag of 20 years. Clusters in Detroit and Iowa were detected at several time points.
We found significant spatial clusters of NHL after allowing for disease latency and residential mobility. Our results show the importance of evaluating residential histories when studying spatial patterns of cancer.
Smoking, alcohol use, and obesity appear to increase the risk of developing non-Hodgkin lymphoma (NHL), but few studies have assessed their impact on NHL prognosis.
We evaluated the association of pre-diagnosis cigarette smoking, alcohol use, and body mass index (BMI) on overall survival in 1,286 patients enrolled through population-based registries in the United States from 1998–2000. Hazard Ratios (HR) and 95% confidence intervals (CI) were estimated using Cox regression, adjusting for clinical and demographic factors.
Through 2007, 442 patients died (34%), and the median follow-up on living patients was 7.7 years. Compared to never smokers, former (HR=1.59; 95% CI 1.12–2.26) and current (HR=1.50; 95% CI 0.97–2.29) smokers had poorer survival, and poorer survival was positively associated with smoking duration, number of cigarettes smoked per day, pack-years of smoking, and shorter time since quitting (all p-trend<0.01). Alcohol use was associated with poorer survival (p-trend=0.03); compared to non-users, those drinking more than 43.1 grams/week (median of intake among drinkers) had poorer survival (HR=1.55; 95% CI 1.06–2.27) while those drinkers consuming less than this amount showed no survival disadvantage (HR=1.13; 95% CI 0.75–1.71). Greater body mass index was associated with poorer survival (p-trend=0.046), but the survival disadvantage was only seen among obese individuals (HR=1.32 for BMI ≥30 versus 20–24.9 kg/m2; 95% CI 1.02–1.70). These results held for lymphoma-specific survival and were broadly similar for DLBCL and follicular lymphoma.
NHL patients who smoked, consumed alcohol or were obese prior to diagnosis had a poorer overall and lymphoma-specific survival.
alcohol; non-Hodgkin lymphoma; obesity; smoking; survival
By assessing the spectrum of hematologic malignancies associated with solid organ transplantation in the elderly, we provide information on the pathogenesis of lymphoid and myeloid neoplasms and the clinical manifestations of immunosuppression.
Using data from the U.S. Surveillance, Epidemiology, and End Results (SEER) Medicare database, we identified 83,016 cases with a hematologic malignancy (age 66-99 years) and 166,057 population-based controls matched to cases by age, sex, and calendar year. Medicare claims were used to identify a history of solid organ transplantation. We utilized polytomous logistic regression to calculate odds ratios (ORs) comparing transplantation history among cases with various hematologic malignancy subtypes and controls, adjusting for the matching factors and race.
A prior solid organ transplant was identified in 216 (0.26%) cases and 204 (0.12%) controls. Transplantation was associated with increased risk for non-Hodgkin lymphomas (NHLs) (OR=2.13, 95%CI 1.67-2.72), especially diffuse large B-cell lymphoma (OR=3.29, 95%CI 2.28-4.76), marginal zone lymphoma (OR=2.48, 95%CI 1.17-5.22), lymphoplasmacytic lymphoma (OR=3.32, 95%CI 1.41-7.81), and T-cell lymphoma (OR=3.07, 95%CI 1.56-6.06). Transplantation was also associated with elevated risk of Hodgkin lymphoma (OR=2.53, 95%CI 1.01-6.35) and plasma cell neoplasms (OR=1.91, 95%CI 1.24-2.93). Risks for myeloid neoplasms were also elevated (OR=1.99, 95%CI 1.41-2.81).
Solid organ transplantation is associated with a wide spectrum of hematologic malignancies in the elderly. Risk was increased for four specific NHL subtypes for which a viral agent has been implicated, supporting an added role for immunosuppression.
Our results support monitoring for a wide spectrum of hematologic malignancies following solid organ transplant.
transplantation; lymphoma; myeloma; leukemia; United States
Previous epidemiologic findings suggest an association between exposure to trichloroethylene (TCE), a chlorinated solvent primarily used for vapor degreasing of metal parts, and non-Hodgkin lymphoma (NHL).
We investigated the association between occupational TCE exposure and NHL within a population-based case–control study using detailed exposure assessment methods.
Cases (n = 1,189; 76% participation rate) and controls (n = 982; 52% participation rate) provided information on their occupational histories and, for selected occupations, on possible workplace exposure to TCE using job-specific interview modules. An industrial hygienist assessed potential TCE exposure based on this information and a review of the TCE industrial hygiene literature. We computed odds ratios (ORs) and 95% confidence intervals (CIs) relating NHL and different metrics of estimated TCE exposure, categorized using tertiles among exposed controls, with unexposed subjects as the reference group.
We observed associations with NHL for the highest tertiles of estimated average weekly exposure (23 exposed cases; OR = 2.5; 95% CI, 1.1–6.1) and cumulative exposure (24 exposed cases; OR = 2.3; 95% CI, 1.0–5.0) to TCE. Tests for trend with these metrics surpassed or approached statistical significance (p-value for trend = 0.02 and 0.08, respectively); however, we did not observe dose–response relationships across the exposure levels. Overall, neither duration nor intensity of exposure was associated with NHL, although we observed an association with the lowest tertile of exposure duration (OR = 2.1; 95% CI, 1.0–4.7).
Our findings offer additional support for an association between high levels of exposure to TCE and increased risk of NHL. However, we cannot rule out the possibility of confounding from other chlorinated solvents used for vapor degreasing and note that our exposure assessment methods have not been validated.
cancer; non-Hodgkin lymphoma; occupational; solvents; trichloroethylene
Genetic variation may be an important risk factor for multiple myeloma. A hallmark of tumor formation and growth is cell cycle dysregulation and apoptosis avoidance. We previously reported the association of genetic variation in caspase genes, the apoptotic-regulating family, and multiple myeloma risk. To further examine if genetic variation in key cell cycle and apoptosis genes alters multiple myeloma risk, we genotyped 276 tag SNPs in 27 gene regions in a population-based case-control study of non-Hispanic Caucasian women (108 cases; 482 controls) in Connecticut. Logistic regression assessed the effect of each SNP on multiple myeloma risk and the minP test assessed the association at the gene region level. Three gene regions were significantly associated with risk of multiple myeloma (BAX minP = 0.018, CASP9 minP = 0.025, and RIPK1 minP = 0.037). Further explorations identified the most significant variant of BAX, RIPK1, and CASP9 to be rs1042265, rs9391981, and rs751643, respectively. The A variant at rs1042265 (ORGA+AA = 0.40, 95%CI = 0.21 – 0.78) and the C variant at rs9391981 (ORGC+CC = 0.32, 95%CI = 0.12 – 0.81) were associated with a decreased risk of multiple myeloma. The G variant at rs7516435 was associated with an increased risk of multiple myeloma (ORAG = 1.48, 95%CI = 0.94 – 2.32; ORGG = 2.59, 95%CI = 1.30 – 5.15; ptrend = 0.005). Haplotype analyses supported the SNP findings. These findings suggest that genetic variation in cell cycle and apoptosis genes may play a key role in multiple myeloma and warrant further investigation through replication studies.
multiple myeloma; caspase; BAX; RIPK1; cell cycle
Cigarette smoke contains many carcinogens that are metabolically activated through xenobiotic metabolism by phase I and II enzymes, including N-acetyltransferases 1 and 2 (NAT1 and NAT2). We investigated non-Hodgkin lymphoma (NHL) risk in general and by subtype in relation to NAT1 and NAT2 genotypes and cigarette smoking in a population-based case-control study in Connecticut. We found a 2-fold increased risk of T-cell lymphoma among those possessing the NAT1*10 haplotype compared to those with other NAT1 haplotypes; including an OR of 2.2 (95%CI: 1.1–4.5) for those heterozygous for NAT1*10 and an OR of 2.0 (95% CI: 1.0–2.4) for those heterozygous or homozygous for NAT1*10 genotypes. Rapid acetylator NAT2 phenotype increased the risk of both T-cell lymphoma (OR=3.2; 95% CI: 1.1–9.5) and marginal zone lymphoma (OR=3.0; 95% CI: 1.0–8.7). When NAT1 and NAT2 genotypes were stratified by smoking status, an increased risk of NHL overall was observed in ever (OR=1.5; 95% CI: 1.1–2.1) and current (OR=1.7; 95% CI: 1.2–2.4) smokers without the NAT1*10 haplotype. No association between history of cigarette smoking and risk of NHL overall was observed with NAT1*10 haplotype or NAT2 genotype.
non-Hodgkin lymphoma; NAT1; NAT2; smoking; single nucleotide polymorphisms
Elevated incidence of lymphoma has been observed among carriers of rare high-penetrance mutations in DNA repair genes (e.g., Nijmegen breakage syndrome, Ataxia-telangectasia syndrome, etc.). Common gene variants in DNA repair genes may also influence lymphomagenesis.
Study subjects were pooled from three population-based case-control studies of non-Hodgkin lymphoma (NHL) in the US and Australia. A total of 1,946 cases and 1,808 controls were analyzed. A total of 319 tag single nucleotide polymorphisms (SNPs) in 27 DNA repair gene regions were genotyped. Unconditional logistic regression models were used to estimate the relative risk of NHL and NHL subtypes in relation to SNPs. Tail-strength statistics were used to test for the association between DNA repair pathways and NHL or NHL subtypes. The statistical significance of the smallest P-trend within each gene region was estimated by permutation-based resampling methods.
Overall, DNA repair genetic polymorphisms were associated with NHL (P = 0.005). Tests for the double strand break repair (P = 0.02) and nucleotide excision repair (P = 0.04) pathways were also significant. Four gene regions were significantly associated with NHL or NHL subtypes at the 0.05 level: RAD50, BLM, RAD51/FAM82C, and ERCC3/MAP3K2. Specifically, BLM rs441399 (P trend = 0.004) and FAM82C rs2304583 (P trend = 0.001) were associated with follicular lymphoma, and XRCC4 rs13178127 was associated with NHL overall (P trend = 0.006) significantly. In addition, the ERCC3 rs4150506 was associated with reduced risk for marginal zone lymphoma (P trend = 0.002).
These results support the hypothesis that common genetic polymorphisms in human DNA repair genes may modify the risk of NHL.
non-Hodgkin lymphoma; DNA repair; single nucleotide polymorphism; pooled analysis
Some autoimmune conditions are associated with increased risk of lymphoid malignancies, but information on specific malignancy subtypes is limited. From the U.S. Surveillance Epidemiology and End Results-Medicare database, we selected 44,350 lymphoid malignancy cases (≥67 years) and 122,531 population-based controls. Logistic regression was used to derive odds ratios (ORs) comparing the prevalence of autoimmune conditions in cases and controls, by lymphoid malignancy subtype, adjusted for gender, age at malignancy/selection, year of malignancy/selection, race and number of physician claims. The strongest associations observed by Non-Hodgkin lymphoma (NHL) subtypes were diffuse large B-cell lymphoma with rheumatoid arthritis (OR 1.4, 95%CI 1.2-1.5) and Sjögren syndrome (2.0, 1.5-2.8); T-cell lymphoma with hemolytic anemia (9.7, 4.3-22), psoriasis (3.1, 2.5-4.0), discoid lupus erythematosus (4.4, 2.3-8.4), and celiac disease (5.0, 2.4-14.); and marginal zone lymphoma with Sjögren syndrome (6.6, 4.6-9.5), systemic lupus erythematosus (2.8, 1.7-4.7), and hemolytic anemia (7.4, 3.1-18). Hodgkin lymphoma was associated with several autoimmune conditions. Multiple myeloma was associated only with pernicious anemia (1.5, 1.3-1.7). Several autoimmune conditions were associated with increased risk of lymphoid neoplasms, especially NHLs of diffuse large B-cell, marginal zone and T-cell subtypes. These results support a mechanism whereby chronic antigenic stimulation leads to lymphoid malignancy.
Chromosomal translocations are the hallmark genetic aberration in non-Hodgkin lymphoma (NHL), with specific translocations often selectively associated with specific NHL subtypes. Because many NHL-associated translocations involve cell cycle, apoptosis, and lymphocyte development regulatory genes, we evaluated NHL risk associated with common genetic variation in 20 candidate genes in these pathways. Genotyping of 203 tag single nucleotide polymorphisms (SNPs) was conducted in 1946 NHL cases and 1808 controls pooled from three independent population-based case-control studies. We used logistic regression to compute odds ratios (OR) and 95% confidence intervals (CI) for NHL and four major NHL subtypes in relation to tag SNP genotypes and haplotypes. We observed the most striking associations for tag SNPs in the pro-apoptotic gene BCL2L11 (BIM) and BCL7A, which is involved in a rare NHL-associated translocation. Variants in BCL2L11 were strongly related to follicular lymphoma only, particularly rs3789068 (ORAG=1.41, 95%CI 1.10–1.81; ORGG=1.65, 95%CI 1.25–2.19; p-trend=0.0004). Variants in BCL7A were strongly related to diffuse large B-cell lymphoma only, particularly rs1880030 (ORAG=1.34, 95%CI 1.08–1.68; ORAA=1.60, 95%CI 1.22–2.08; p-trend=0.0004). The associations for both variants were similar in all three studies and supported by haplotype analyses. We also observed notable associations for variants in BCL6, CCND1, and MYC. Our results support the role of common genetic variation in cell cycle, apoptosis, and lymphocyte development regulatory genes in lymphomagenesis, and suggest that effects may vary by NHL subtype. Replication of our findings and further study to identify functional SNPs are warranted.
lymphoma; non-Hodgkin; polymorphism; single nucleotide; apoptosis; cell cycle
Studies indicate that higher sun exposure, especially in the recent past, is associated with reduced risk of non-Hodgkin lymphoma (NHL). Ultraviolet radiation-derived vitamin D may be protective against lymphomagenesis. We examined the relationship between pre-diagnostic serum 25-hydroxyvitamin D (25(OH)D) and lymphoid cancer risk in a case-control study nested within the Alpha-Tocopherol Beta-Carotene Cancer Prevention Study cohort (1985–2002) of 29,133 Finnish male smokers (ages 50 to 69). We identified 270 incident lymphoid cancer cases and matched them individually with 538 controls by birth-year and month of fasting blood draw at baseline. In conditional logistic regression models for 10nmol/L increments or tertile comparisons, serum 25(OH)D was not associated with the risk of overall lymphoid cancers, NHL (N = 208), or multiple myeloma (N = 41). Odds ratios (OR) for NHL for higher tertiles were 0.75 (95% confidence interval (CI), 0.50, 1.14) and 0.82 (95% CI, 0.53, 1.26). The 25(OH)D-NHL association, however, differed by follow-up duration at diagnosis. Cases diagnosed less than 7 years from the baseline showed an inverse association (OR for highest versus lowest tertile = 0.43; 95% CI: 0.23, 0.83; p for trend = 0.01), but not later diagnoses (OR = 1.52; 95% CI: 0.82, 2.80; p for trend = 0.17). The inverse association found for close exposure to diagnosis was not confounded by other risk factors for lymphoma or correlates of 25(OH)D. Although our findings suggest that circulating 25(OH)D is not likely associated with overall lymphoid cancer, they indicate a potentially protective effect on short-term risk of NHL.
25-hydroxyvitamin D; diet; lymphoid neoplasms; nested case-control studies; non-Hodgkin lymphoma; vitamin D
Toll-like receptors (TLRs) may influence the development of non-Hodgkin lymphoma (NHL) given their important roles in recognizing microbial pathogens and stimulating multiple immune pathways. We conducted an investigation of TLR gene variants in a pooled analysis including three population-based case–control studies of NHL (1946 cases and 1808 controls). Thirty-six tag single-nucleotide polymorphisms (SNPs) in TLR2, TLR4 and the TLR10–TLR1–TLR6 gene cluster were genotyped. Two TLR10–TLR1–TLR6 variants in moderate linkage disequilibrium were significantly associated with NHL: rs10008492 [odds ratio for CT genotype (ORCT) 1.12, 95% confidence interval (CI) 0.97–1.30; ORTT 1.40, 95% CI 1.15–1.71; Ptrend = 0.001] and rs4833103 (ORAC 0.75, 95% CI 0.64–0.88; ORAA 0.74, 95% CI 0.62–0.90; Ptrend = 0.002; Pdominant = 0.0002). Associations with these SNPs were consistent across all the three studies and did not appreciably differ by histologic subtype. We found little evidence of association between TLR2 variation and all NHL, although the rare variant rs3804100 was significantly associated with marginal zone lymphoma (MZL), both overall (ORCT/CC 1.89, 95% CI 1.27–2.81; Pdominant = 0.002) and in two of the three studies. No associations with TLR4 variants were observed. This pooled analysis provides strong evidence that variation in the TLR10–TLR1–TLR6 region is associated with NHL risk and suggests that TLR2 variants may influence susceptibility to MZL.