Eleanor V. Willett

Autoimmune disorders and risk of non-Hodgkin lymphoma subtypes: a pooled analysis within the InterLymph Consortium

Some autoimmune disorders are increasingly recognized as risk factors for non-Hodgkin lymphoma (NHL) overall, but large-scale systematic assessments of risk of NHL subtypes are lacking. We performed a pooled analysis of self-reported autoimmune conditions and risk of NHL and subtypes, including 29 423 participants in 12 case-control studies. We computed pooled odds ratios (OR) and 95% confidence intervals (CI) in a joint fixed-effects model. Sjögren syndrome was associated with a 6.5-fold increased risk of NHL, a 1000-fold increased risk of parotid gland marginal zone lymphoma (OR = 996; 95% CI, 216-4596), and with diffuse large B-cell and follicular lymphomas. Systemic lupus erythematosus was associated with a 2.7-fold increased risk of NHL and with diffuse large B-cell and marginal zone lymphomas. Hemolytic anemia was associated with diffuse large B-cell NHL. T-cell NHL risk was increased for patients with celiac disease and psoriasis. Results for rheumatoid arthritis were heterogeneous between studies. Inflammatory bowel disorders, type 1 diabetes, sarcoidosis, pernicious anemia, and multiple sclerosis were not associated with risk of NHL or subtypes. Thus, specific autoimmune disorders are associated with NHL risk beyond the development of rare NHL subtypes in affected organs. The pattern of associations with NHL subtypes may harbor clues to lymphomagenesis.

Genetic variation in TNF and IL10 and risk of non-Hodgkin lymphoma: a report from the InterLymph Consortium

BACKGROUND Common genetic variants in immune and inflammatory response genes can affect the risk of developing non-Hodgkin lymphoma. We aimed to test this hypothesis using previously unpublished data from eight European, Canadian, and US case-control studies of the International Lymphoma Epidemiology Consortium (InterLymph). METHODS We selected 12 single-nucleotide polymorphisms for analysis, on the basis of previous functional or association data, in nine genes that have important roles in lymphoid development, Th1/Th2 balance, and proinflammatory or anti-inflammatory pathways (IL1A, IL1RN, IL1B, IL2, IL6, IL10, TNF, LTA, and CARD15). Genotype data for one or more single-nucleotide polymorphisms were available for 3586 cases of non-Hodgkin lymphoma and for 4018 controls, and were assessed in a pooled analysis by use of a random-effects logistic regression model. FINDINGS The tumour necrosis factor (TNF) -308G-->A polymorphism was associated with increased risk of non-Hodgkin lymphoma (p for trend=0.005), particularly for diffuse large B-cell lymphoma, the main histological subtype (odds ratio 1.29 [95% CI 1.10-1.51] for GA and 1.65 [1.16-2.34] for AA, p for trend <0.0001), but not for follicular lymphoma. The interleukin 10 (IL10) -3575T-->A polymorphism was also associated with increased risk of non-Hodgkin lymphoma (p for trend=0.02), again particularly for diffuse large B-cell lymphoma (p for trend=0.006). For individuals homozygous for the TNF -308A allele and carrying at least one IL10 -3575A allele, risk of diffuse large B-cell lymphoma doubled (2.13 [1.37-3.32], p=0.00083). INTERPRETATION Common polymorphisms in TNF and IL10, key cytokines for the inflammatory response and Th1/Th2 balance, could be susceptibility loci for non-Hodgkin lymphoma. Moreover, our results underscore the importance of consortia for investigating the genetic basis of chronic diseases like cancer.

Fast track — ArticlesGenetic variation in TNF and IL10 and risk of non-Hodgkin lymphoma: a report from the InterLymph Consortium

BACKGROUND Common genetic variants in immune and inflammatory response genes can affect the risk of developing non-Hodgkin lymphoma. We aimed to test this hypothesis using previously unpublished data from eight European, Canadian, and US case-control studies of the International Lymphoma Epidemiology Consortium (InterLymph). METHODS We selected 12 single-nucleotide polymorphisms for analysis, on the basis of previous functional or association data, in nine genes that have important roles in lymphoid development, Th1/Th2 balance, and proinflammatory or anti-inflammatory pathways (IL1A, IL1RN, IL1B, IL2, IL6, IL10, TNF, LTA, and CARD15). Genotype data for one or more single-nucleotide polymorphisms were available for 3586 cases of non-Hodgkin lymphoma and for 4018 controls, and were assessed in a pooled analysis by use of a random-effects logistic regression model. FINDINGS The tumour necrosis factor (TNF) -308G-->A polymorphism was associated with increased risk of non-Hodgkin lymphoma (p for trend=0.005), particularly for diffuse large B-cell lymphoma, the main histological subtype (odds ratio 1.29 [95% CI 1.10-1.51] for GA and 1.65 [1.16-2.34] for AA, p for trend <0.0001), but not for follicular lymphoma. The interleukin 10 (IL10) -3575T-->A polymorphism was also associated with increased risk of non-Hodgkin lymphoma (p for trend=0.02), again particularly for diffuse large B-cell lymphoma (p for trend=0.006). For individuals homozygous for the TNF -308A allele and carrying at least one IL10 -3575A allele, risk of diffuse large B-cell lymphoma doubled (2.13 [1.37-3.32], p=0.00083). INTERPRETATION Common polymorphisms in TNF and IL10, key cytokines for the inflammatory response and Th1/Th2 balance, could be susceptibility loci for non-Hodgkin lymphoma. Moreover, our results underscore the importance of consortia for investigating the genetic basis of chronic diseases like cancer.

Polymorphism in glutathione S-transferase P1 is associated with susceptibility to chemotherapy-induced leukemia

Glutathione S-transferases (GSTs) detoxify potentially mutagenic and toxic DNA-reactive electrophiles, including metabolites of several chemotherapeutic agents, some of which are suspected human carcinogens. Functional polymorphisms exist in at least three genes that encode GSTs, including GSTM1, GSTT1, and GSTP1. We hypothesize, therefore, that polymorphisms in genes that encode GSTs alter susceptibility to chemotherapy-induced carcinogenesis, specifically to therapy-related acute myeloid leukemia (t-AML), a devastating complication of long-term cancer survival. Elucidation of genetic determinants may help to identify individuals at increased risk of developing t-AML. To this end, we have examined 89 cases of t-AML, 420 cases of de novo AML, and 1,022 controls for polymorphisms in GSTM1, GSTT1, and GSTP1. Gene deletion of GSTM1 or GSTT1 was not specifically associated with susceptibility to t-AML. Individuals with at least one GSTP1 codon 105 Val allele were significantly over-represented in t-AML cases compared with de novo AML cases [odds ratio (OR), 1.81; 95% confidence interval (CI), 1.11–2.94]. Moreover, relative to de novo AML, the GSTP1 codon 105 Val allele occurred more often among t-AML patients with prior exposure to chemotherapy (OR, 2.66; 95% CI, 1.39–5.09), particularly among those with prior exposure to known GSTP1 substrates (OR, 4.34; 95% CI, 1.43–13.20), and not among those t-AML patients with prior exposure to radiotherapy alone (OR,1.01; 95% CI, 0.50–2.07). These data suggest that inheritance of at least one Val allele at GSTP1 codon 105 confers a significantly increased risk of developing t-AML after cytotoxic chemotherapy, but not after radiotherapy.

Cigarette Smoking and Risk of Non-Hodgkin Lymphoma: A Pooled Analysis from the International Lymphoma Epidemiology Consortium (InterLymph)

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.

Personal sun exposure and risk of non Hodgkin lymphoma: A pooled analysis from the Interlymph Consortium

In 2004–2007 4 independent case‐control studies reported evidence that sun exposure might protect against NHL; a fifth, in women only, found increased risks of NHL associated with a range of sun exposure measurements. These 5 studies are the first to examine the association between personal sun exposure and NHL. We report here on the relationship between sun exposure and NHL in a pooled analysis of 10 studies participating in the International Lymphoma Epidemiology Consortium (InterLymph), including the 5 published studies. Ten case‐control studies covering 8,243 cases and 9,697 controls in the USA, Europe and Australia contributed original data for participants of European origin to the pooled analysis. Four kinds of measures of self‐reported personal sun exposure were assessed at interview. A two‐stage estimation method was used in which study‐specific odds ratios (ORs) and 95% confidence intervals (CIs), adjusted for potential confounders including smoking and alcohol use, were obtained from unconditional logistic regression models and combined in random‐effects models to obtain the pooled estimates. Risk of NHL fell significantly with the composite measure of increasing recreational sun exposure, pooled OR = 0.76 (95% CI 0.63–0.91) for the highest exposure category (p for trend 0.01). A downtrend in risk with increasing total sun exposure was not statistically significant. The protective effect of recreational sun exposure was statistically significant at 18–40 years of age and in the 10 years before diagnosis, and for B cell, but not T cell, lymphomas. Increased recreational sun exposure may protect against NHL.

Alcohol consumption and risk of non-Hodgkin lymphoma: a pooled analysis

BACKGROUND Previous epidemiological studies of the relation between alcohol consumption and risk of non-Hodgkin lymphoma (NHL) have been inconsistent, probably because of small sample sizes of individual studies that result from stratification by NHL subtype and type of alcoholic beverage. We aimed to assess the role of alcohol consumption in NHL with sufficient sample size to analyse by both type of alcoholic beverage and disease subtype. METHODS We obtained original data from nine case-control studies from the USA, UK, Sweden, and Italy in the International Lymphoma Epidemiology Consortium (InterLymph), yielding a pooled study population of 15 175 individuals (6492 cases and 8683 controls). We derived odds ratios (OR) and 95% CI from unconditional logistic regression models, controlling for study centre and other confounding factors. Heterogeneity between studies was assessed by comparison of results from joint fixed-effects logistic regression and two-stage random-effects logistic regression, and by calculation of Wald chi(2) statistics. FINDINGS People who drank alcohol had a lower risk of NHL than did non-drinkers (OR 0.83 [95% CI 0.76-0.89]). Compared with non-drinkers, risk estimates were lower for current drinkers than for former drinkers (0.73 [0.64-0.84] vs 0.95 [0.80-1.14]), but risk did not decrease with increasing alcohol consumption. The protective effect of alcohol did not vary by beverage type, but did change with NHL subtype. The lowest risk estimates were recorded for Burkitts lymphoma (0.51 [0.33-0.77]). INTERPRETATION People who drink alcoholic beverages might have a lower risk of NHL than those who do not, and this risk might vary by NHL subtype. Further study designs are needed to determine whether confounding lifestyle factors or immunomodulatory effects of alcohol explain this association.

Cigarette smoking and risk of non-Hodgkin lymphoma: a pooled analysis from the InterLymph Consortium

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.

Non-Hodgkin lymphoma and obesity: A pooled analysis from the InterLymph Consortium

Nutritional status is known to alter immune function, a suspected risk factor for non‐Hodgkin lymphoma (NHL). To investigate whether long‐term over, or under, nutrition is associated with NHL, self‐reported anthropometric data on weight and height from over 10,000 cases of NHL and 16,000 controls were pooled across 18 case‐control studies identified through the International Lymphoma Epidemiology Consortium. Study‐specific odds ratios (OR) were estimated using logistic regression and combined usinga random‐effects model. Severe obesity, defined as BMI of 40 kg m−2 or more, was not associated with NHL overall (pooled OR = 1.00, 95% confidence interval (CI) 0.70–1.41) or the majority of NHL subtypes. An excess was however observed for diffuse large B‐cell lymphoma (pooled OR = 1.80, 95% CI 1.24–2.62), although not all study‐specific ORs were raised. Among the overweight (BMI 25–29.9 kg m−2) and obese (BMI 30–39.9 kg m−2), associations were elevated in some studies and decreased in others, while no association was observed among the underweight (BMI < 18.5 kg m−2). There was little suggestion of increasing ORs for NHL or its subtypes with every 5 kg m−2 rise in BMI above 18.5 kg m−2. BMI components height and weight were also examined, and the tallest men, but not women, were at marginally increased risk (pooled OR = 1.19, 95% CI 1.06–1.34). In summary, whilst we conclude that there is no evidence to support the hypothesis that obesity is a determinant of all types of NHL combined, the association between severe obesity and diffuse large B‐cell lymphoma may warrant further investigation.

Risk of non-Hodgkin lymphoma associated with polymorphisms in folate-metabolizing genes

Genetic instability, including chromosomal imbalance, is important in the pathogenesis of lymphoproliferative disorders such as non–Hodgkin lymphoma (NHL). DNA synthesis and methylation, which are closely linked to folate metabolism and transport, may be affected by polymorphisms in genes involved in these pathways. Folate metabolism polymorphisms have been linked to acute lymphoblastic leukemia and colorectal cancer. To evaluate whether genetic variation in folate metabolism and transport may have a role in determining the risk of developing NHL, we analyzed several polymorphisms using DNA obtained as part of a large U.K. population-based case-control study of lymphoma. Polymorphisms studied include methylenetetrahydrofolate reductase (MTHFR) 677 C>T and 1298 A>C, methionine synthase (MTR) 2756 A>G, serine hydroxymethyltransferase (SHMT1) 1420 C>T, thymidylate synthase (TYMS) 1494del6 and 28–bp repeat, and reduced folate carrier (RFC) 80 G>A. Increased risks for NHL [odds ratio (OR), 1.48; 95% confidence intervals (CI), 1.12-1.97], and marginal zone lymphoma (OR, 3.38; 95% CI, 1.30-8.82) were associated with the TYMS 2R/3R variant. Marginal increased risks were also observed for diffuse large B cell lymphoma with the TYMS homozygous 6 bp deletion (OR, 1.61; 95% CI, 0.99-2.60) and for follicular lymphoma with RFC 80AA (OR, 1.44; 95% CI, 0.94-2.22) and TYMS 28–bp repeat 2R/3R (OR, 1.45; 95% CI, 0.96-2.2). We observed no association between NHL and haplotypes for MTHFR or TYMS. These findings are somewhat inconsistent with those of others, but may reflect differences in circulating folate levels between study populations. Thus, further investigations are warranted in larger series with dietary information to determine the roles that genetics and folic acid status play in the etiology of lymphoma. (Cancer Epidemiol Biomarkers Prev 2005;14(12):2999–3003)