The role of dietary factors in non-Hodgkin lymphoma (NHL) risk is not yet well understood. Dietary flavonoids are polyphenolic compounds proposed to be anticarcinogenic. Flavonoids are well-characterized antioxidants and metal chelators, and certain flavonoids exhibit antiproliferative and antiestrogenic effects.
We aimed to evaluate the hypothesis that higher flavonoid intake is associated with lower NHL risk.
During 1998–2000, we identified incident NHL cases aged 20–74 y from 4 US Surveillance, Epidemiology, and End Results cancer registries. Controls without history of NHL were selected by random-digit dialing or from Medicare files and frequency-matched to cases by age, center, race, and sex. Using 3 recently developed US Department of Agriculture nutrient-specific databases, flavonoid intake was estimated from participant responses to a 117-item food-frequency questionnaire (n = 466 cases and 390 controls). NHL risk in relation to flavonoid intake in quartiles was evaluated after adjustment for age, sex, registry, education, NHL family history, and energy intake.
Higher total flavonoid intake was significantly associated with lower risk of NHL (P for trend < 0.01): a 47% lower risk in the highest quartile of intake than in the lowest (95% CI: 31%, 73%). Higher intakes of flavonols, epicatechins, anthocyanidins, and proanthocyanidins were each significantly associated with decreased NHL risk. Similar patterns of risk were observed for the major NHL subtypes—diffuse large B-cell lymphoma (n = 167) and follicular lymphoma (n = 146).
A higher intake of flavonoids, dietary components with several putative anticarcinogenic activities, may be associated with lower NHL risk.
Background & Aims
Increasing evidence points towards a role of hepatitis C virus (HCV) infection in causing malignant lymphomas. We pooled case-control study data to provide robust estimates of the risk of non-Hodgkin’s lymphoma (NHL) subtypes after HCV infection.
The analysis included 7 member studies from the International Lymphoma Epidemiology Consortium (InterLymph) based in Europe, North America, and Australia. Adult cases of NHL (n = 4784) were diagnosed between 1988 and 2004 and controls (n = 6269) were matched by age, sex, and study center. All studies used third-generation enzyme-linked immunosorbent assays to test for antibodies against HCV in serum samples. Participants who were human immunodeficiency virus positive or were organ-transplant recipients were excluded.
HCV infection was detected in 172 NHL cases (3.60%) and in 169 (2.70%) controls (odds ratio [OR], 1.78; 95% confidence interval [CI], 1.40–2.25). In subtype-specific analyses, HCV prevalence was associated with marginal zone lymphoma (OR, 2.47; 95% CI, 1.44–4.23), diffuse large B-cell lymphoma (OR, 2.24; 95% CI, 1.68–2.99), and lymphoplasmacytic lymphoma (OR, 2.57; 95% CI, 1.14–5.79). Notably, risk estimates were not increased for follicular lymphoma (OR, 1.02; 95% CI, 0.65–1.60).
These results confirm the association between HCV infection and NHL and specific B-NHL subtypes (diffuse large B-cell lymphoma, marginal zone lymphoma, and lymphoplasmacytic lymphoma).
The incidence of NHL has increased dramatically since at least the 1950s, and during this timeframe there has been a major increase in the use of blood transfusions, invasive surgical procedures, and anesthesia, all of which can impact immune function. We evaluated these factors with NHL risk in a population-based study of 759 cases and 589 frequency-matched controls. Risk factor data were collected during in-person interviews. Unconditional logistic regression was used to estimate ORs and 95% CIs, adjusted for the matching factors. History of transfusion was associated with a 26% higher risk of NHL (95% CI 0.91–1.73), and the elevated risk was specific to transfusions first given 5–29 years before the reference date (OR=1.69; 95% CI 1.08–2.62) and transfusions given for a medical condition (OR=2.09; 95% CI 1.03–4.26). The total number of surgeries and dental procedures (OR=1.53 for 26+ surgeries compared to 0–6; 95% CI 1.02–2.29) and to a lesser extent the total number of exposures to general or local/regional anesthesia (OR=1.35 for 24+ times compared to 0–6; 95% CI 0.91–2.02) were positively associated with risk of NHL. Inclusion of transfusion and surgery or transfusion and anesthesia in the same model did not attenuate these associations. All results were broadly consistent for both DLBCL and follicular subtypes. Blood transfusions were associated with NHL risk, but appear to be a marker for underlying medical conditions. Multiple surgical procedures and/or repeated administration of anesthesia have not been previously reported to be associated with risk of NHL and these exposures warrant further evaluation.
anesthesia; blood transfusion; non-Hodgkin lymphoma; surgery
Endotoxin, a component of the outer membrane of gram-negative bacteria, elicits a strong innate and inflammatory immune response associated with secretion of pro-inflammatory cytokines, including tumor necrosis factor-alpha (TNF-α). Because TNF-α polymorphisms that increase TNF-α production are associated with an increased risk of non-Hodgkin lymphoma (NHL), we hypothesized that increased levels of household endotoxin would be associated with an increased NHL risk.
We evaluated this association in the National Cancer Institute/Surveillance, Epidemiology and End Result (NCI/SEER) NHL multi-center population-based case-control study. Used vacuum cleaner bags were collected from participants during a home interview. Dust samples from the bags of 594 cases and 442 controls were analyzed for endotoxin (Endotoxin Unit [EU]/mg of dust) using the kinetic chromogenic Limulus amebocyte lysate assay. Multivariable logistic regression was used to estimate the effect of endotoxin on NHL risk adjusted for age, sex, race, education, study center, and farm exposure.
Endotoxin was not associated with NHL overall (odds ratio [OR] for highest quartile of endotoxin levels = 0.81, 95% confidence interval [CI]= 0.55,1.20; P for trend=0.35), or with diffuse large B-cell lymphoma (OR= 0.63, 95% CI= 0.34, 1.16; P= 0.31) or follicular lymphoma (OR= 0.1.07, 95% CI=0.61, 1.89; P=0.73) subtypes. Both working and living on a farm were associated with higher household endotoxin levels compared to never working (P=0.009) or living (P=0.01) on a farm. Excluding farmers from the analysis did not change the results.
We found no evidence of a role for household endotoxin in NHL etiology.
Endotoxin; Non-Hodgkin lymphoma; Epidemiology; Farming; Risk; Case-control
Genome-wide association studies (GWAS) have revolutionized the field of cancer genetics, but the causal links between increased genetic risk and onset/progression of disease processes remain to be identified. Here we report the first step in such an endeavor for prostate cancer. We provide a comprehensive annotation of the 77 known risk loci, based upon highly correlated variants in biologically relevant chromatin annotations— we identified 727 such potentially functional SNPs. We also provide a detailed account of possible protein disruption, microRNA target sequence disruption and regulatory response element disruption of all correlated SNPs at . 88% of the 727 SNPs fall within putative enhancers, and many alter critical residues in the response elements of transcription factors known to be involved in prostate biology. We define as risk enhancers those regions with enhancer chromatin biofeatures in prostate-derived cell lines with prostate-cancer correlated SNPs. To aid the identification of these enhancers, we performed genomewide ChIP-seq for H3K27-acetylation, a mark of actively engaged enhancers, as well as the transcription factor TCF7L2. We analyzed in depth three variants in risk enhancers, two of which show significantly altered androgen sensitivity in LNCaP cells. This includes rs4907792, that is in linkage disequilibrium () with an eQTL for NUDT11 (on the X chromosome) in prostate tissue, and rs10486567, the index SNP in intron 3 of the JAZF1 gene on chromosome 7. Rs4907792 is within a critical residue of a strong consensus androgen response element that is interrupted in the protective allele, resulting in a 56% decrease in its androgen sensitivity, whereas rs10486567 affects both NKX3-1 and FOXA-AR motifs where the risk allele results in a 39% increase in basal activity and a 28% fold-increase in androgen stimulated enhancer activity. Identification of such enhancer variants and their potential target genes represents a preliminary step in connecting risk to disease process.
In the following work we provide a complete summary annotation of functional hypotheses relating to risk identified by genome wide association studies of prostate cancer. In addition, we present new genome-wide profiles for H3K27-acetylation and TCF7L2 binding in LNCaP cells. We also introduce the concept of a risk enhancer, and characterize two novel androgen-sensitive enhancers whose activity is specifically affected by prostate-cancer risk SNPs. Our findings represent a preliminary approach to systematic identification of causal variation underlying cancer risk in the prostate.
Studies of smoking and risk of non-Hodgkin lymphoma (NHL) have yielded inconsistent results, possibly due to subtype heterogeneity and/or genetic variation impacting the metabolism of tobacco-derived carcinogens, including substrates of the N-acetyltransferase enzymes NAT1 and NAT2.
We conducted a pooled analysis of 5,026 NHL cases and 4,630 controls from seven case–control studies in the international lymphoma epidemiology consortium to examine associations between smoking, variation in the N-acetyltransferase genes NAT1 and NAT2, and risk of NHL subtypes. Smoking data were harmonized across studies, and genetic variants in NAT1 and NAT2 were used to infer acetylation phenotype of the NAT1 and NAT2 enzymes, respectively. Pooled odds ratios (ORs) and 95 % confidence intervals (95 % CIs) for risk of NHL and subtypes were calculated using joint fixed effects unconditional logistic regression models.
Current smoking was associated with a significant 30 % increased risk of follicular lymphoma (n = 1,176) but not NHL overall or other NHL subtypes. The association was similar among NAT2 slow (OR 1.36; 95 % CI 1.07–1.75) and intermediate/rapid (OR 1.27; 95 % CI 0.95–1.69) acetylators (pinteraction = 0.82) and also did not differ by NAT1*10 allelotype. Neither NAT2 phenotype nor NAT1*10 allelotype was associated with risk of NHL overall or NHL subtypes.
The current findings provide further evidence for a modest association between current smoking and follicular lymphoma risk and suggest that this association may not be influenced by variation in the N-acetyltransferase enzymes.
Non-Hodgkin lymphoma; Gene environment interaction; Cigarette smoking; N-acetyltransferase; Follicular lymphoma
Background: Human papillomavirus (HPV) is estimated to play an etiologic role in 40–50% of penile cancers worldwide. Estimates of HPV prevalence in U.S. penile cancer cases are limited.
Methods: HPV DNA was evaluated in tumor tissue from 79 invasive penile cancer patients diagnosed in 1998–2005 within the catchment areas of seven U.S. cancer registries. HPV was genotyped using PCR-based Linear Array and INNO-LiPA assays and compared by demographic, clinical, and pathologic characteristics and survival. Histological classification was also obtained by independent pathology review.
Results: HPV DNA was present in 50 of 79 (63%) of invasive penile cancer cases. Sixteen viral genotypes were detected. HPV 16, found in 46% (36/79) of all cases (72% of HPV-positive cases) was the most prevalent genotype followed equally by HPV 18, 33, and 45, each of which comprised 5% of all cases. Multiple genotypes were detected in 18% of viral positive cases. HPV prevalence did not significantly vary by age, race/ethnicity, population size of geographic region, cancer stage, histology, grade, penile subsite, or prior cancer history. Penile cases diagnosed in more recent years were more likely to be HPV-positive. Overall survival did not significantly vary by HPV status.
Conclusion: The relatively high prevalence of HPV in our study population provides limited evidence of a more prominent and, possibly, increasing role of infection in penile carcinogenesis in the U.S. compared to other parts of the world.
human papillomavirus; HPV; prevalence; penile cancer; United States
We performed a pooled analysis of data on self-reported history of infections in relation to the risk of non-Hodgkin lymphoma (NHL) from 17 case-control studies that included 12,585 cases and 15,416 controls aged 16–96 years at recruitment. Pooled odds ratios (OR) and 95% confidence intervals (95% CI) were estimated in two-stage random-effect or joint fixed-effect models, adjusting for age, sex and study centre. Data from the two years prior to diagnosis (or date of interview for controls) were excluded. A self-reported history of infectious mononucleosis (IM) was associated with an excess risk of NHL (OR=1.26, 95% CI=1.01–1.57 based on data from 16 studies); study-specific results indicate significant (I2=51%, p=0.01) heterogeneity. A self-reported history of measles or whooping cough was associated with an approximate 15% reduction in risk. History of other infection was not associated with NHL. We find little clear evidence of an association between NHL risk and infection although the limitations of data based on self-reported medical history (particularly of childhood illness reported by older people) are well recognised.
There is growing evidence linking genetic variations to non–Hodgkin lymphoma (NHL) etiology. To complement ongoing agnostic approaches for identifying susceptibility genes, we evaluated 488 candidate gene regions and their relation to risk for NHL and NHL subtypes.
We genotyped 6,679 tag single nucleotide polymorphisms (SNPs) in 947 cases and 826 population-based controls from a multicenter U.S. case–control study. Gene-level summary of associations were obtained by computing the minimum P value (“minP test”) on the basis of 10,000 permutations. We used logistic regression to evaluate the association between genotypes and haplotypes with NHL. For NHL subtypes, we conducted polytomous multivariate unconditional logistic regression (adjusted for sex, race, age). We calculated P-trends under the codominant model for each SNP.
Fourteen gene regions were associated with NHL (P < 0.01). The most significant SNP associated with NHL maps to the SYK gene (rs2991216, P-trend = 0.00005). The three most significant gene regions were on chromosome 6p21.3 (RING1/RXRB; AIF1; BAT4). Accordingly, SNPs in RING1/RXRB (rs2855429), AIF1 (rs2857597), and BAT4 (rs3115667) were associated with NHL (P-trends ≤ 0.0002) and both diffuse large B-cell and follicular lymphomas (P-trends < 0.05).
Our results suggest potential importance for SYK on chromosome 9 with NHL etiology. Our results further implicate 6p21.3 gene variants, supporting the need for full characterization of this chromosomal region in relation to lymphomagenesis.
Gene variants on chromosome 9 may represent a new region of interesting for NHL etiology. The independence of the reported variants in 6p21.3 from implicated variants (TNF/HLA) supports the need to confirm causal variants in this region
Body-mass-index (BMI) has been inversely associated with lung and upper aerodigestive tract (UADT) cancers. However, only a few studies have assessed BMI change in adulthood in relation to cancer. To understand the relationship between BMI change and these cancers in both men and women, we analyzed data from a population-based case-control study conducted in Los Angeles County. Adulthood BMI change was measured as the proportional change in BMI between age 21 and one year prior to interview or diagnosis. Five categories of BMI change were included and individuals with no more than a 5% loss or gain were defined as having a stable BMI (reference group). Adjusted odds ratios (ORs) and their 95% confidence intervals (CIs) were estimated using logistic regression models. Potential confounders included age, gender, ethnicity, education, tobacco smoking, and energy intake. For UADT cancers, we also adjusted for alcohol drinking status and frequency. A BMI gain of 25% or higher in adulthood was inversely associated with lung cancer (OR 0.53, 95% CI 0.33-0.84) and UADT cancers (OR 0.44, 95% CI 0.27-0.71). In subgroup analyses, a BMI gain of ≥25% was inversely associated with lung and UADT cancers among current and former smokers, as well as among current and former alcohol drinkers. The inverse association persisted among moderate and heavy smokers (≥20 pack-years). The observed inverse associations between adulthood BMI gain and lung and UADT cancers indicate a potential role for body weight-related biological pathways in the development of lung and UADT cancers.
BMI; lung cancer; upper aerodigestive tract cancer; tobacco smoking; metabolism
Childbearing at an older age has been associated with a lower risk of endometrial cancer, but whether the association is independent of the number of births or other factors remains unclear. Individual-level data from 4 cohort and 13 case-control studies in the Epidemiology of Endometrial Cancer Consortium were pooled. A total of 8,671 cases of endometrial cancer and 16,562 controls were included in the analysis. After adjustment for known risk factors, endometrial cancer risk declined with increasing age at last birth (Ptrend < 0.0001). The pooled odds ratio per 5-year increase in age at last birth was 0.87 (95% confidence interval: 0.85, 0.90). Women who last gave birth at 40 years of age or older had a 44% decreased risk compared with women who had their last birth under the age of 25 years (95% confidence interval: 47, 66). The protective association was similar across the different age-at-diagnosis groups and for the 2 major tumor histologic subtypes (type I and type II). No effect modification was observed by body mass index, parity, or exogenous hormone use. In this large pooled analysis, late age at last birth was independently associated with a reduced risk of endometrial cancer, and the reduced risk persisted for many years.
endometrial neoplasms; parity; reproductive history
Follicular lymphoma (FL) has variable progression and survival, and improved identification of patients at high risk for progression would aid in identifying patients most likely to benefit from alternative therapy. In a sample of 244 FL cases identified during a population-based case-control study of non-Hodgkin lymphoma (NHL), we examined 6,679 tag SNPs in 488 gene regions for associations with overall FL survival. Over a median follow-up of 89 months with 65 deaths in this preliminary study, we identified 5 gene regions (BMP7, GALNT12, DUSP2, GADD45B, and ADAM17) that were associated with overall survival from FL. Results did not meet the criteria for statistical significance after adjustment for multiple hypothesis testing. These results, which support a role for host factors in determining the variable progression of FL, serve as an initial examination that can inform future studies of genetic variation and FL survival. However, they require replication in independent populations, as well as assessment in rituximab-treated patients.
follicular lymphoma; genetic variation; survival; tag SNP; case-control study
Exploring spatial-temporal patterns of disease incidence and mortality can identify areas of significantly elevated or decreased risk, providing potential etiologic clues. Several methodological issues arise in spatial-temporal analysis of cancer, including population mobility, disease latency, and confounding, but applying modern statistical methods to case-control studies with residential histories can address these issues. As an example, we present a spatial-temporal analysis of non-Hodgkin lymphoma (NHL) risk using data from Los Angeles County, one of four centers in a population-based case-control study. Using residential histories, we fitted generalized additive models (GAMs) adjusted for known risk factors to model spatially the probability that an individual had NHL and identify areas of significantly elevated NHL risk. In previous analyses using models with single lag times, the lag time of 20 years yielded the most significant decrease in model deviance. To better assess cumulative effects of unmeasured environmental exposures over space and time, we considered models that allowed for multiple residences per subject through spatial smoothing functions of residential location at different times. We found that the model with the best goodness-of-fit included components for residential change and residential duration, although the model that included residential duration was not meaningfully better than the model that included only residential change. The estimated cumulative spatial risk surface from the model with residential change amplified the risk surface in some areas compared with the surface based on the model with a single component for the most significant time lag.
cancer; generalized additive model; spatial risk; latency; exposure
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
Residence near municipal solid waste incinerators, a major historical source of dioxin emissions, has been associated with increased risk of non-Hodgkin lymphoma (NHL) in European studies. The aim of our study was to evaluate residence near industrial combustion facilities and estimates of dioxin emissions in relation to NHL risk in the United States.
We conducted a population-based case–control study of NHL (1998–2000) in four National Cancer Institute-Surveillance Epidemiology and End Results centers (Detroit, Iowa, Los Angeles, Seattle). Residential histories 15 years before diagnosis (similar date for controls) were linked to an Environmental Protection Agency database of dioxin-emitting facilities for 969 cases and 749 controls. We evaluated proximity (3 and 5 km) to 10 facility types that accounted for >85% of U.S. emissions and a distance-weighted average emission index (AEI [ng toxic equivalency quotient (TEQ)/year]).
Proximity to any dioxin-emitting facility was not associated with NHL risk (3 km OR = 1.0, 95% CI 0.8-1.3). Risk was elevated for residence near cement kilns (5 km OR = 1.7, 95% CI 0.8-3.3; 3 km OR = 3.8, 95% CI 1.1-14.0) and reduced for residence near municipal solid waste incinerators (5 km OR = 0.5, 95% CI 0.3-0.9; 3 km OR = 0.3, 95% CI 0.1-1.4). The AEI was not associated with risk of NHL overall. Risk for marginal zone lymphoma was increased for the highest versus lowest quartile (5 km OR = 2.6, 95% CI 1.0-6.8; 3 km OR = 3.0, 95% CI 1.1-8.3).
Overall, we found no association with residential exposure to dioxins and NHL risk. However, findings for high emissions and marginal zone lymphoma and for specific facility types and all NHL provide some evidence of an association and deserve future study.
Non-Hodgkin lymphoma; Lymphomas; Dioxins; Air pollution; Geographic information systems; Case–control study
Recent increases in incidence and survival of oropharyngeal cancers in the United States have been attributed to human papillomavirus (HPV) infection, but empirical evidence is lacking.
Patients and Methods
HPV status was determined for all 271 oropharyngeal cancers (1984-2004) collected by the three population-based cancer registries in the Surveillance, Epidemiology, and End Results (SEER) Residual Tissue Repositories Program by using polymerase chain reaction and genotyping (Inno-LiPA), HPV16 viral load, and HPV16 mRNA expression. Trends in HPV prevalence across four calendar periods were estimated by using logistic regression. Observed HPV prevalence was reweighted to all oropharyngeal cancers within the cancer registries to account for nonrandom selection and to calculate incidence trends. Survival of HPV-positive and HPV-negative patients was compared by using Kaplan-Meier and multivariable Cox regression analyses.
HPV prevalence in oropharyngeal cancers significantly increased over calendar time regardless of HPV detection assay (P trend < .05). For example, HPV prevalence by Inno-LiPA increased from 16.3% during 1984 to 1989 to 71.7% during 2000 to 2004. Median survival was significantly longer for HPV-positive than for HPV-negative patients (131 v 20 months; log-rank P < .001; adjusted hazard ratio, 0.31; 95% CI, 0.21 to 0.46). Survival significantly increased across calendar periods for HPV-positive (P = .003) but not for HPV-negative patients (P = .18). Population-level incidence of HPV-positive oropharyngeal cancers increased by 225% (95% CI, 208% to 242%) from 1988 to 2004 (from 0.8 per 100,000 to 2.6 per 100,000), and incidence for HPV-negative cancers declined by 50% (95% CI, 47% to 53%; from 2.0 per 100,000 to 1.0 per 100,000). If recent incidence trends continue, the annual number of HPV-positive oropharyngeal cancers is expected to surpass the annual number of cervical cancers by the year 2020.
Increases in the population-level incidence and survival of oropharyngeal cancers in the United States since 1984 are caused by HPV infection.
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
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
Survivors of pediatric Hodgkin lymphoma (HL) are at significant risk for radiation therapy (RT)-induced second malignant neoplasms (SMNs). We identified two variants at chromosome 6q21 associated with SMNs in HL survivors treated with RT as children but not as adults. The variants comprise a risk locus associated with decreased basal PRDM1 expression and impaired induction of PRDM1 by radiation exposure. These data suggest a novel gene-exposure interaction that may implicate PRDM1 in the etiology of RT-induced SMNs.
Genetic variations in human leukocyte antigens (HLA) are critical in host responses to infections, transplantation, and immunological diseases. We previously identified associations with non-Hodgkin lymphoma (NHL) and the HLA-DRB1*01:01 allele and extended ancestral haplotype (AH) 8.1 (HLA-A*01-B*08-DR*03-TNF-308A). To illuminate how HLA alleles and haplotypes may influence NHL etiology, we examined potential interactions between HLA-DRB1*01:01 and AH 8.1, and a wide range of NHL risk factors among 685 NHL cases and 646 controls from a United States population-based case-control study. We calculated odds ratios and 95% confidence intervals by HLA allele or haplotype status, adjusted for sex, age, race and study center for NHL and two major subtypes using polychotomous unconditional logistic regression models. The previously reported elevation in NHL risk associated with exposures to termite treatment and polychlorinated biphenyls were restricted to individuals who did not possess HLA-DRB1*01:01. Previous associations for NHL and DLBCL with decreased sun exposure, higher BMI, and autoimmune conditions were statistically significant only among those with AH 8.1, and null among those without AH 8.1. Our results suggest that NHL risk factors vary in their association based on HLA-DRB1*01:01 and AH 8.1 status. Our results further suggest that certain NHL risk factors may act through a common mechanism to alter NHL risk. Finally, control participants with either HLA-DRB1*01:01 or AH 8.1 reported having a family history of NHL twice as likely as those who did not have either allele or haplotype, providing the first empirical evidence that HLA associations may explain some of the well-established relationship between family history and NHL risk.
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
Adenocarcinomas located near the gastroesophageal junction have unclear etiology and are difficult to classify. We used DNA methylation analysis to identify subtype-specific markers and new subgroups of gastroesophageal adenocarcinomas, and studied their association with epidemiological risk factors and clinical outcomes.
We used logistic regression models and unsupervised hierarchical cluster analysis of 74 DNA methylation markers on 45 tumor samples (44 patients) of esophageal and gastric adenocarcinomas obtained from a population-based case-control study to uncover epigenetic markers and cluster groups of gastroesophageal adenocarcinomas. No distinct epigenetic differences were evident between subtypes of gastric and esophageal cancers. However, we identified two gastroesophageal adenocarcinoma subclusters based on DNA methylation profiles. Group membership was best predicted by GATA5 DNA methylation status. We analyzed the associations between these two epigenetic groups and exposure using logistic regression, and the associations with survival time using Cox regression in a larger set of 317 tumor samples (278 patients). There were more males with esophageal and gastric cardia cancers in Cluster Group 1 characterized by higher GATA5 DNA methylation values (all p<0.05). This group also showed associations of borderline statistical significance with having ever smoked (p-value = 0.07), high body mass index (p-value = 0.06), and symptoms of gastroesophageal reflux (p-value = 0.07). Subjects in cluster Group 1 showed better survival than those in Group 2 after adjusting for tumor differentiation grade, but this was not found to be independent of tumor stage.
DNA methylation profiling can be used in population-based studies to identify epigenetic subclasses of gastroesophageal adenocarcinomas and class-specific DNA methylation markers that can be linked to epidemiological data and clinical outcome. Two new epigenetic subgroups of gastroesophageal adenocarcinomas were identified that differ to some extent in their survival rates, risk factors of exposure, and GATA5 DNA methylation.
The higher incidence of acute lymphoblastic leukemia (ALL) among Hispanic children relative to that in other racial/ethnic groups is well-known. We evaluated incidence patterns of ALL in adults.
We analyzed the incidence patterns of ALL (ICD-03 codes 9835–9837) among all patients diagnosed from 1988–2004 in California using data from the California Cancer Registry to determine whether adult Hispanics also had higher incidence rates of ALL compared to non-Hispanic Whites (Whites). Age-adjusted incidence rates (AAIR), incidence rate ratios (IRR) and 5-year survival rates were obtained using SEER*Stat. AAIRs of other leukemia subtypes and IRRs relative to non-Hispanic whites were also examined as references of ALL.
AAIRs of ALL in Hispanic males and females ages 20–54 years were higher compared to those in White males and females (IRR=1.99,95% CI=1.74–2.28 and IRR=1.91,95% CI=1.60–2.25 respectively). A higher AAIR of ALL was also observed among older (55+ years) Hispanic females (IRR=1.84, 95% CI=1.52–2.21), but not males (IRR= 1.07, 95% CI= 0.84–1.34). Among Hispanics, low socioeconomic status (SES) was associated with a higher AAIR compared to high/middle SES (IRR= 1.33, 95% CI=1.04–1.70). The respective five-year survival rates among ALL patients were 38% and 30% for Whites and Hispanics ages 20–54 years, and 8% and 12% for patients 55 years of age or older. Compared to other racial/ethnic groups, Hispanics did not have an increased IRR of the other major leukemia subtypes.
Hispanics experience a higher incidence of ALL throughout life, but not other subtypes.