Morton, Lindsay M

AbstractUnderstanding patterns of etiologic commonality and heterogeneity for non-Hodgkin lymphomas may illuminate lymphomagenesis. We present the first systematic comparison of risks by lymphoma subtype for a broad range of putative risk factors in a population-based case-control study, including diffuse large B-cell (DLBCL; N = 416), follicular (N = 318), and marginal zone lymphomas (N = 106), and chronic lymphocytic leukemia/small lymphocytic lymphoma (CLL/SLL; N = 133). We required at least 2 of 3 analyses to support differences in risk: (1) polytomous logistic regression, (2) homogeneity tests, or (3) dichotomous logistic regression, analyzing all 7 possible pairwise comparisons among the subtypes, corresponding to various groupings by clinical behavior, genetic features, and differentiation. Late birth order and high body mass index (≥ 35) kg/m2) increased risk for DLBCL alone. Autoimmune conditions increased risk for marginal zone lymphoma alone. The tumor necrosis factor G-308A polymorphism (rs1800629) increased risks for both DLBCL and marginal zone lymphoma. Exposure to certain dietary heterocyclic amines from meat consumption increased risk for CLL/SLL alone. We observed no significant risk factors for follicular lymphoma alone. These data clearly support both etiologic commonality and heterogeneity for lymphoma subtypes, suggesting that immune dysfunction is of greater etiologic importance for DLBCL and marginal zone lymphoma than for CLL/SLL and follicular lymphoma.

AbstractTo evaluate the hypothesis that host germ line variation in immune genes is associated with overall survival in diffuse large B-cell lymphoma (DLBCL), we genotyped 73 single nucleotide polymorphisms (SNPs) from 44 candidate genes in 365 DLBCL patients diagnosed from 1998 to 2000. We estimated hazard ratios (HRs) and 95% confidence intervals (CIs) for the association of SNPs with survival after adjusting for clinical factors. During follow-up, 96 (26%) patients died, and the median follow-up was 57 months for surviving patients. The observed survival of this cohort was consistent with population-based estimates conditioned on surviving 12 months. An IL10 haplotype (global P = .03) and SNPs in IL8RB (rs1126580; HRAG/GG = 2.11; CI, 1.28-3.50), IL1A (rs1800587; HRCT/TT = 1.90; CI, 1.26-2.87), TNF (rs1800629; HRAG/GG = 1.44; CI, 0.95-2.18), and IL4R (rs2107356; HRCC/CT = 1.97; CI, 1.01-3.83) were the strongest predictors of overall survival. A risk score that combined the latter 4 SNPs with clinical factors was strongly associated with survival in a Cox model (P = 6.0 × 10−11). Kaplan-Meier 5-year survival estimates for low, intermediate-low, intermediate-high, and high-risk patients were 94%, 79%, 60%, and 48%, respectively. These data support a role for germ line variation in immune genes, particularly genes associated with a proinflammatory state, as predictors of late survival in DLBCL.

Abstract Two common single nucleotide polymorphisms in immunoregulatory genes (TNF G308A, rs1800629 and IL10 T3575A, rs1800890) have been recently reported as risk factors for non–Hodgkin lymphoma (NHL) in a large pooled analysis. We systematically investigated the effects of other established NHL risk factors in relation to the tumor necrosis factor (TNF) G308A or interleukin 10 (IL10) T3575A genotypes. We calculated odds ratios (OR) and 95% confidence intervals (95% CI) from 1,172 cases and 982 population-based controls in a U.S. multicenter study. We investigated NHL overall and two common subtypes [diffuse large B-cell lymphoma (DLBCL) and follicular lymphoma]. NHL risks were increased among those with both an autoimmune condition and the TNF G308A GA/AA (ORNHL, 2.1; 95% CI, 1.0–4.2) or the IL10 T3575A TA/AA genotype (ORNHL, 1.6; 95% CI, 0.9–2.6) compared with individuals without an autoimmune condition and with the common TNF G308A GG or IL10 T3575A TT genotype, respectively; results were similar for DLBCL and follicular lymphoma. We found that elevated DLBCL risk associated with last-born status was more pronounced among those with TNF G308A GA/AA (ORDLBCL, 2.7; 95% CI, 1.1–6.4) or IL10 T3575A TA/AA (ORDLBCL, 2.9; 95% CI, 1.6–5.2). Similarly, elevated DLBCL risk associated with obesity (body mass index, ≥35 versus <25 kg/m2) was observed only among those with TNF G308A GA/AA (ORDLBCL, 2.5; 95% CI, 1.1–5.7) or IL10 T3575A TA/AA genotypes (ORDLBCL, 2.0; 95% CI, 1.1–3.5). These exploratory results require replication but provide evidence that autoimmune conditions, late birth order, and obesity act partly through a common inflammatory pathway, posing a greater risk to individuals with variant TNF and IL10 genotypes than those with wild-type alleles. [Cancer Res 2007;67(10):5042–54]

Abstract Recent evidence suggests that there is etiologic heterogeneity among the various subtypes of lymphoid neoplasms. However, epidemiologic analyses by disease subtype have proven challenging due to the numerous clinical and pathologic schemes used to classify lymphomas and lymphoid leukemias over the last several decades. On behalf of the International Lymphoma Epidemiology Consortium (InterLymph) Pathology Working Group, we present a proposed nested classification of lymphoid neoplasms to facilitate the analysis of lymphoid neoplasm subtypes in epidemiologic research. The proposed classification is based on the World Health Organization classification of lymphoid neoplasms and the International Classification of Diseases–Oncology, Third Edition (ICD-O-3). We also provide a translation into the proposed classification from previous classifications, including the Working Formulation, Revised European-American Lymphoma (REAL) classification, and ICD-O-2. We recommend that epidemiologic studies include analyses by lymphoma subtype to the most detailed extent allowable by sample size. The standardization of groupings for epidemiologic research of lymphoma subtypes is essential for comparing subtype-specific reports in the literature, harmonizing cases within a single study diagnosed using different systems, as well as combining data from multiple studies for the purpose of pooled analysis or meta-analysis, and will probably prove to be critical for elucidating etiologies of the various lymphoid neoplasms.

AbstractRecent gene-expression data have suggested that host immune genetic signatures may predict outcomes in patients with follicular lymphoma. We evaluated the hypothesis that germ line common variation in candidate immune genes is associated with survival. Cox models were used to estimate hazard ratios (HR) and corresponding 95% confidence intervals for individual SNPs after accounting for age, clinical, and other demographic factors. The median age at diagnosis of the 278 patients was 57 years, and 59 (21%) of the patients died during follow-up, with a median follow-up of 59 months (range, 27-78 months) for surviving patients. SNPs in IL8 (rs4073; HRTT = 2.14, 1.26-3.63), IL2 (rs2069762; HRGT/TT = 1.80, 1.06-3.05), IL12B (rs3212227; HRAC/CC = 1.83, 1.06-3.06), and IL1RN (rs454078; HRAA = 1.93, 1.11-3.34) were the most robust predictors of survival. A summary score of the number of deleterious genotypes from these genes was strongly associated with survival (P = .001). A risk score that combined the 4 SNPs with the clinical and demographic factors was even more strongly associated with survival (P < .001); the 5-year Kaplan-Meier survival estimates were 96% (93%-100%), 72% (62%-83%), and 58% (48%-72%) for groups at low, intermediate, and high risk, respectively. Common variation in host immune genes warrants further evaluation as a promising class of prognostic factors in follicular lymphoma.

Abstract Background: The International Lymphoma Epidemiology Consortium (InterLymph) provides an opportunity to analyze the relationship between cigarette smoking and non-Hodgkin lymphoma with sufficient statistical power to consider non-Hodgkin lymphoma subtype. The results from previous studies of this relationship have been inconsistent, likely due to the small sample sizes that arose from stratification by disease subtype. To clarify the role of cigarette smoking in the etiology of non-Hodgkin lymphoma, we conducted a pooled analysis of original patient data from nine case-control studies of non-Hodgkin lymphoma conducted in the United States, Europe, and Australia. Methods: Original data were obtained from each study and uniformly coded. Risk estimates from fixed-effects and two-stage random-effects models were compared to determine the impact of interstudy heterogeneity. Odds ratios (OR) and 95% confidence intervals (95% CI) were derived from unconditional logistic regression models, controlling for study center, age, sex, and race. Results: In our pooled study population of 6,594 cases and 8,892 controls, smoking was associated with slightly increased risk estimates (OR, 1.07; 95% CI, 1.00-1.15). Stratification by non-Hodgkin lymphoma subtype revealed that the most consistent association between cigarette smoking and non-Hodgkin lymphoma was observed among follicular lymphomas (n = 1452). Compared with nonsmokers, current smokers had a higher OR for follicular lymphoma (1.31; 95% CI, 1.12-1.52) than former smokers (1.06; 95% CI, 0.93-1.22). Current heavy smoking (≥36 pack-years) was associated with a 45% increased OR for follicular lymphoma (1.45; 95% CI, 1.15-1.82) compared with nonsmokers. Conclusions: Cigarette smoking may increase the risk of developing follicular lymphoma but does not seem to affect risk of the other non-Hodgkin lymphoma subtypes we examined. Future research is needed to determine the biological mechanism responsible for our subtype-specific results.