Smoking and hematolymphopoietic malignancies

Chitosan as possible inhibitory agents and delivery systems in leukemia

Leukemia is a lethal cancer in which white blood cells undergo proliferation and immature white blood cells are seen in the bloodstream. Without diagnosis and management in early stages, this type of cancer can be fatal. Changes in protooncogenic genes and microRNA genes are the most important factors involved in development of leukemia. At present, leukemia risk factors are not accurately identified, but some studies have pointed out factors that predispose to leukemia. Studies show that in the absence of genetic risk factors, leukemia can be prevented by reducing the exposure to risk factors of leukemia, including smoking, exposure to benzene compounds and high-dose radioactive or ionizing radiation. One of the most important treatments for leukemia is chemotherapy which has devastating side effects. Chemotherapy and medications used during treatment do not have a specific effect and destroy healthy cells besides leukemia cells. Despite the suppressing effect of chemotherapy against leukemia, patients undergoing chemotherapy have poor quality of life. So today, researchers are focusing on finding more safe and effective natural compounds and treatments for cancer, especially leukemia. Chitosan is a valuable natural compound that is biocompatible and non-toxic to healthy cells. Anticancer, antibacterial, antifungal and antioxidant effects are examples of chitosan biopolymer properties. The US Food and Drug Administration has approved the use of this compound in medical treatments and the pharmaceutical industry. In this article, we take a look at the latest advances in the use of chitosan in the treatment and improvement of leukemia.

The importance of evaluating specific myeloid malignancies in epidemiological studies of environmental carcinogens

INTRODUCTION

Although myelodysplastic syndrome (MDS), acute myeloid leukemia (AML), myeloproliferative neoplasms (MPN) - including chronic myeloid leukemia (CML) - and myelodysplastic/myeloproliferative neoplasms (MDS/MPN) are largely clinically distinct myeloid malignancies, epidemiological studies rarely examine them separately and often combine them with lymphoid malignancies, limiting possible etiological interpretations for specific myeloid malignancies.

METHODS

We systematically evaluated the epidemiological literature on the four chemical agents (1,3-butadiene, formaldehyde, benzene, and tobacco smoking, excluding pharmaceutical, microbial and radioactive agents, and pesticides) classified by the International Agency for Research on Cancer as having sufficient epidemiological evidence to conclude that each causes "myeloid malignancies." Literature searches of IARC Monographs and PubMed identified 85 studies that we critically assessed, and for appropriate subsets, summarized results using meta-analysis.

RESULTS

Only two epidemiological studies on 1,3-butadiene were identified, but reported findings were inadequate to evaluate specific myeloid malignancies. Studies on formaldehyde reported results for AML and CML - and not for MDS or MPN - but reported no increased risks. For benzene, several specific myeloid malignancies were evaluated, with consistent associations reported with AML and MDS and mixed results for CML. Studies of tobacco smoking examined all major myeloid malignancies, demonstrating consistent relationships with AML, MDS and MPN, but not with CML.

CONCLUSIONS

Surprisingly few epidemiological studies present results for specific myeloid malignancies, and those identified were inconsistent across studies of the same exposure, as well as across chemical agents. This exercise illustrates that even for agents classified as having sufficient evidence of causing "myeloid malignancies," the epidemiological evidence for specific myeloid malignancies is generally limited and inconsistent. Future epidemiological studies should report findings for the specific myeloid malignancies, as combining them post hoc - where appropriate - always remains possible, whereas disaggregation may not. Furthermore, combining results across possibly discrete diseases reduces the chances of identifying important malignancy-specific causal associations.

Coffee and tea consumption and risk of leukaemia in an adult population: A reanalysis of the Italian multicentre case-control study

BACKGROUND

Coffee and tea are the most frequently consumed beverages in the world. Their potential effect on the risk of developing different types of malignancies has been largely investigated, but studies on leukaemia in adults are scarce.

METHODS

The present investigation is aimed at evaluating the potential role of regular coffee and tea intake on the risk of adult leukaemia by reanalysing a large population based case-control study carried out in Italy, a country with a high coffee consumption and a low use of green tea. Interviewed subjects, recruited between 1990 and 1993 in 11 Italian areas, included 1771 controls and 651 leukaemia cases. Association between Acute Myeloid Leukaemia (AML), Acute Lymphoid Leukaemia, Chronic Myeloid Leukaemia, Chronic Lymphoid Leukaemia, and use of coffee and tea was evaluated by standard logistic regression. Odds Ratios (OR) were estimated adjusting for the following potential confounders: gender, age, residence area, smoking habit, educational level, previous chemotherapy treatment, alcohol consumption and exposure to electromagnetic fields, radiation, pesticides and aromatic hydrocarbons.

RESULTS

No association was observed between regular use of coffee and any type of leukaemia. A small protective effect of tea intake was found among myeloid malignancies, which was more evident among AML (OR=0.68, 95%CI: 0.49-0.94). However, no clear dose-response relation was found.

CONCLUSION

The lower risk of leukaemia among regular coffee consumers, reported by a few of previous small studies, was not confirmed. The protective effect of tea on the AML risk is only partly consistent with results from other investigations.

Do the smoking intensity and duration, the years since quitting, the methodological quality and the year of publication of the studies affect the results of the meta-analysis on cigarette smoking and Acute Myeloid Leukemia (AML) in adults?

BACKGROUND

The aim was to perform a systematic review and meta-analysis on the relationship between tobacco smoking and the onset of acute myeloid leukemia (AML) in adults.

METHODS

PubMed and Scopus databases were systematically searched. In the meta-analysis, random or fixed effects models were used according to the presence of heterogeneity. Study quality was assessed using the Newcastle-Ottawa Scale.

RESULTS

Twenty-seven articles were included. Case-control and cohort meta-analyses show that current, ever and former smokers have a significant increased risk to develop AML compared to never smokers [current: OR=1.36 (1.11-1.66) and RR=1.52 (1.10-2.14); ever: OR=1.25 (1.14-1.38) and RR=1.45 (1.10-1.90); former: OR=1.21 (1.03-1.41) and RR=1.45 (1.08-1.94)]. Moreover, increasing smoking intensity and duration is associated with an increase of the risk, OR shift from 1.14 (1-20 pack/years) to 2.36 (>40 pack/years).

DISCUSSION AND CONCLUSION

Smoking may have a significant role in AML onset in a multistep pathogenesis.

Polycyclic aromatic hydrocarbons: determinants of residential carpet dust levels and risk of non-Hodgkin lymphoma

PURPOSE

To investigate the risk of non-Hodgkin lymphoma (NHL) associated with residential carpet dust measurements of polycyclic aromatic hydrocarbons (PAHs).

METHODS

We evaluated the relationship between residential carpet dust PAH concentrations (benz(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(k)fluoranthene, chrysene, dibenz(a,h)anthracene, and indeno(1,2,3-c,d)pyrene, and their sum) and risk of NHL (676 cases, 511 controls) in the National Cancer Institute Surveillance Epidemiology and End Results multicenter case-control study. As a secondary aim, we investigated determinants of dust PAH concentrations. We computed odds ratios (OR) and 95 % confidence interval (CI) for associations between NHL and concentrations of individual and summed PAHs using unconditional logistic regression, adjusting for age, gender, and study center. Determinants of natural log-transformed PAHs were investigated using multivariate least-squares regression.

RESULTS

We observed some elevated risks for NHL overall and B cell lymphoma subtypes in association with quartiles or tertiles of PAH concentrations, but without a monotonic trend, and there was no association comparing the highest quartile or tertile to the lowest. In contrast, risk of T cell lymphoma was significantly increased among participants with the highest tertile of summed PAHs (OR = 3.04; 95 % CI, 1.09-8.47) and benzo(k)fluoranthene (OR = 3.20; 95 % CI, 1.13-9.11) compared with the lowest tertile. Predictors of PAH dust concentrations in homes included ambient air PAH concentrations and the proportion of developed land within 2 km of a residence. Older age, more years of education, and white race were also predictive of higher levels in homes.

CONCLUSION

Our results suggest a potential link between PAH exposure and risk of T cell lymphoma and demonstrate the importance of analyzing risk by NHL histologic type.

Cigarette Smoking and the Risk of Adult Myeloid Disease: A Meta-Analysis

Background

The adult myeloid diseases, myelodysplastic syndrome and acute myeloid leukemia, have been reported to be associated with cigarette smoking, but the results have been conflicting. Previous studies may have ignored the relationship between myelodysplastic syndrome and acute myeloid leukemia, where approximately one-third of myelodysplastic syndrome cases will progress to acute myeloid leukemia, which could induce a serious bias in independent analyses. For the purposes of researching pathogenesis, we suggest that myelodysplastic syndrome and acute myeloid leukemia should be regarded as a single class of adult myeloid disease, and herein assessed the relationship between cigarette smoking and the risk of adult myeloid disease.

Methods

The PubMed, Cochrane Library, EBSCO, and EMBASE databases were systematically searched for reports published from 1990 to 2015. Two authors independently assessed the methodological quality and the extracted data. The odds ratios and adjusted odds ratios (OR), a sensitivity analysis, and the publication bias were analyzed using the CMA v2 (Comprehensive Meta Analysis Version 2) software program.

Results

Twenty-five studies were included in this meta-analysis. The publication dates ranged from 1990 to 2014. The pooled OR in current smokers and ever-smokers showed an increased risk of adult myeloid disease, with ORs of 1.45 (95% CI, 1.30–1.62; p<0.001) and 1.23 (95% CI 1.15–1.32; p<0.001) versus non-smokers, respectively. In the subset analyses, the OR of adult myeloid disease was increased regardless of the form of disease, geographical region, NOS (Newcastle Ottawa Scale) score, and source of controls. The smoking status was divided into <20 and ≥20 cigarettes per day, and these groups had ORs of developing adult myeloid disease of 1.24 (95% CI, 1.09–1.40; p = 0.001) and 1.32 (95% CI, 1.14–1.53; p<0.001), respectively. In the groups divided based on the number of years the subjects had smoked (<20 and ≥20 years), the ORs were 1.05 (95% CI, 0.90–1.23; p = 0.25) and 1.30 (95% CI, 1.16–1.45; p<0.001), respectively. Similarly, <20 and ≥20 pack-years were associated with ORs of 1.15 (95% CI, 1.03–1.29; p = 0.017) and 1.34 (95% CI, 1.18–1.52; p<0.001), respectively.

Conclusions

This meta-analysis, for the first time, combined myelodysplastic syndrome with acute myeloid leukemia to assess the overall risk of adult myeloid disease, and it demonstrated that cigarette smoking is associated with a significantly increased risk of adult myeloid disease.

The relation between cigarette smoking and risk of acute myeloid leukemia: an updated meta-analysis of epidemiological studies

Smoking has been postulated as an environmental risk factor for acute myeloid leukemia (AML). The primary objective of this meta-analysis of observational studies was to evaluate the epidemiologic relationship between smoking and the risk of development of AML. Twenty-three studies published between January 1993 and December 2013 were included in our analysis, and accounted for 7,746 cases of AML. The outcome of interest was the relative risk (RR) with 95% confidence interval (CI) of developing AML in adult cigarette smokers in comparison with non-smokers, and was estimated using the random-effects model. Our results showed that current and ever smokers have 40% (RR 1.40, 95% CI 1.22-1.60; P < 0.001) and 25% (RR 1.25, 95% CI 1.15-1.36; P < 0.001) increased risk of developing AML when compared with non-smokers. The increased RR of AML was increased regardless of sex, study design, geographical region, and quality of the studies. Intensity of smoking of <10, 10-20, 20-30, and >30 cigarettes per day was associated with RRs of AML of 1.27, 1.36, 1.55, and 1.77, respectively (P < 0.001 for trend). Duration of smoking of <20 and >20 years was associated with RRs of 1.07 and 1.44, respectively (P < 0.001 for trend). Cumulative smoking of <10, 10-20, 20-30, and >30 pack-years was associated with RRs of 1.13, 1.23, 1.39, and 1.71, respectively (P < 0.001 for trend). Overall, cigarette smoking proves to be a significant risk factor for the development of AML in adults.

Exposure to environmental tobacco smoke and risk of non-Hodgkin lymphoma in nonsmoking men and women

Little is known about the risk of non-Hodgkin lymphoma (NHL) in nonsmokers who are exposed to environmental tobacco smoke (ETS). Previous research on NHL and ETS has not included men or examined doses of ETS exposure during childhood. The Cancer Prevention Study II Nutrition Cohort collected information on smoking habits and exposure to ETS during childhood and adulthood. Among 61,326 never-smoking men and women, 884 incident cases of NHL were identified between 1992 and 2009. Multivariable-adjusted relative risks and 95% confidence intervals were calculated using Cox proportional hazards regression to identify associations between ETS and NHL risk. Compared with no exposure to ETS as a child or an adult, childhood and/or adult ETS exposure was not associated with NHL overall. There was a positive association between the number of smokers in the house as a child (P for trend = 0.05) and exposure to 6 or more hours per week of ETS as an adult (relative risk = 2.37, 95% confidence interval: 1.12, 5.04) with follicular lymphoma risk. Adult ETS exposure was associated with a lower risk of diffuse large B-cell lymphoma (relative risk = 0.68, 95% confidence interval: 0.48, 0.97). This study suggests that adult and childhood ETS exposure may affect the risk of NHL, and that the associations differ by histological subtype.

Childhood infectious diseases and risk of leukaemia in an adult population

Our study is aimed at investigating the association between common childhood infectious diseases (measles, chickenpox, rubella, mumps and pertussis) and the risk of developing leukaemia in an adult population. A reanalysis of a large population-based case-control study was carried out. Original data included 1,771 controls and 649 leukaemia cases from 11 Italian areas. To contain recall bias, the analysis was restricted to subjects directly interviewed and with a good quality interview (1,165 controls and 312 cases). Odds ratios (ORs) and their related 95% confidence intervals (95% CIs) were estimated by unconditional polychotomous logistic regression model adjusting for age, gender and occupational and lifestyle exposures. A protective effect of at least one infection (OR = 0.66, 95% CI: 0.45-0.97), measles (OR = 0.57, 95% CI: 0.39-0.82) and pertussis (OR = 0.66, 95% CI: 0.45-0.98) was observed for chronic lymphoid leukaemia (CLL). The number of infections was strongly inversely associated with the risk of CLL (p = 0.002, test for trend). With regard to the other types of leukaemia, only a protective effect of pertussis was observed for AML (OR = 0.52, 95% CI: 0.32-0.87). Our results pointed out a protective role of childhood infectious diseases on the risk of CLL in adults. Although a specific antioncogenic effect of some infectious disease, especially measles, cannot be ruled out, the observed decrease of risk with increasing number of infections suggests that a more general "hygiene hypothesis" could be the most likely explanation of the detected association. The protective role of pertussis remains to be elucidated.

Cigarette smoking and risk of Hodgkin lymphoma and its subtypes: a pooled analysis from the International Lymphoma Epidemiology Consortium (InterLymph)

BACKGROUND

The etiology of Hodgkin lymphoma (HL) remains incompletely characterized. Studies of the association between smoking and HL have yielded ambiguous results, possibly due to differences between HL subtypes.

PATIENTS AND METHODS

Through the InterLymph Consortium, 12 case-control studies regarding cigarette smoking and HL were identified. Pooled analyses on the association between smoking and HL stratified by tumor histology and Epstein-Barr virus (EBV) status were conducted using random effects models adjusted for confounders. Analyses included 3335 HL cases and 14 278 controls.

RESULTS

Overall, 54.5% of cases and 57.4% of controls were ever cigarette smokers. Compared with never smokers, ever smokers had an odds ratio (OR) of HL of 1.10 [95% confidence interval (CI) 1.01-1.21]. This increased risk reflected associations with mixed cellularity cHL (OR = 1.60, 95% CI 1.29-1.99) and EBV-positive cHL (OR = 1.81, 95% CI 1.27-2.56) among current smokers, whereas risk of nodular sclerosis (OR = 1.09, 95% CI 0.90-1.32) and EBV-negative HL (OR = 1.02, 95% CI 0.72-1.44) was not increased.

CONCLUSION

These results support the notion of etiologic heterogeneity between HL subtypes, highlighting the need for HL stratification in future studies. Even if not relevant to all subtypes, our study emphasizes that cigarette smoking should be added to the few modifiable HL risk factors identified.

Tobacco smoking and risk of multiple myeloma: a meta-analysis of 40 observational studies

This meta-analysis aims to quantitatively synthesize all available data on the association between tobacco smoking and multiple myeloma (MM) risk. Eligible studies were identified and pooled effect estimates (odds ratios and relative risks) were calculated regarding ever, current and former smoking. Separate analyses were performed on case-control and cohort studies, as well as on males and females. Meta-regression analysis with percentage of males, mean age, years of smoking, pack-years, cigarettes per day, years since quit and age at onset was performed. Forty articles were deemed eligible; of them 27 used a case-control design (4,625 cases and 21,591 controls) and 13 used a cohort design (2,228 incident cases among a total cohort size equal to 1,852,763 subjects). Ever smoking was not associated with MM risk (pooled effect estimate = 0.92, 95% confidence interval (CI): 0.85-1.00); similar results were obtained for current (pooled effect estimate = 0.87, 95% CI: 0.74-1.03) and former smoking (pooled effect estimate = 1.04, 95% CI: 0.96-1.13). Regarding ever smoking, the null association was reproducible upon cohort studies (pooled effect estimate = 1.01, 95%CI: 0.89-1.15), whereas the inverse association in case-control studies (pooled effect estimate = 0.87, 95% CI: 0.78-0.96) was particularly due to the bias-prone hospital-based ones. Meta-regression analysis did not yield statistically significant results. In conclusion, MM does not seem to be associated with tobacco smoking. There is a need to further explore how molecular mechanisms are involved in the resistance of MM progenitor cells toward smoking.

Cigarette smoking is associated with a small increase in the incidence of non-Hodgkin lymphoma: a meta-analysis of 24 observational studies

Previous studies have evaluated the association between cigarette smoking and incidence of non-Hodgkin lymphoma (NHL) with inconclusive results. Our main objective was to evaluate this relationship using a meta-analysis of observational studies. A literature search was undertaken through October 2011 looking for pertinent studies. Seven prospective cohort and 17 case-control studies were included in this meta-analysis. Outcomes were calculated using the random-effects model and are reported as odds ratio (OR). Meta-regression was used to evaluate the dose-response of intensity and duration of smoking in NHL incidence. Our study found an OR of 1.40 (95% confidence interval [CI] 1.14-1.73; p = 0.001) in current female smokers seen only in case-control studies. No increased odds of NHL was seen in men. There was no association between smoking and the most common NHL subtypes, with the exception of a statistical trend toward a higher incidence of T-cell lymphoma. In conclusion, there appears to be an increase in the odds of NHL in current female smokers.

Meta-analysis of the association between cigarette smoking and incidence of Hodgkin's Lymphoma

INTRODUCTION

Previous studies have suggested a relationship between smoking and Hodgkin's lymphoma (HL). The main objective of this study was to evaluate this potential association with a meta-analysis of observational studies.

PATIENTS AND METHODS

A literature search was undertaken through December 2010 looking for observational studies evaluating the association between smoking and HL. From 714 articles, 17 were included in this study. Outcome was calculated and reported as odds ratio (OR). Heterogeneity was assessed by using the I(2) index. Publication bias was evaluated by trim-and-fill analysis. Quality assessment was performed with the Newcastle-Ottawa scale.

RESULTS

Our analysis showed an OR of developing HL of 1.35 (95% CI, 1.17 to 1.56; P < .001) in current smokers. Former smokers did not have an increased risk of HL. In subset analyses of current smokers, men and older individuals had ORs of HL of 1.78 (95% CI, 1.46 to 2.17; P < .001) and 1.77 (95% CI, 1.23 to 2.54; P = .002), respectively. In addition, the OR of HL was increased in individuals who smoke more than 20 cigarettes per day, have smoked more than 20 years, or have smoked more than 15 pack-years at 1.51 (95% CI, 1.16 to 1.98; P = .002), 1.84 (95% CI, 1.47 to 2.32; P < .001), and 1.97 (1.53 to 2.54; P < .001), respectively. Meta-regression analyses showed a relative OR of HL of 1.007 (95% CI, 1.001 to 1.013; P = .025) per cigarette per day and of 1.013 (95% CI, 1.006 to 1.019; P < .001) per year of smoking.

CONCLUSION

Smoking seems to increase the odds of developing HL in current smokers. The risk of HL is higher in men and older individuals and increases with higher intensity and longer duration of smoking.

Cigarette smoking, passive smoking, and non-Hodgkin lymphoma risk: evidence from the California Teachers Study

Epidemiologic studies conducted to date have shown evidence of a causal relation between smoking and non-Hodgkin lymphoma (NHL) risk. However, previous studies did not account for passive smoking exposure in the never-smoking reference group. The California Teachers Study collected information about lifetime smoking and household passive smoking exposure in 1995 and about lifetime exposure to passive smoking in 3 settings (household, workplace, and social settings) in 1997-1998. Multivariable-adjusted relative risks and 95% confidence intervals were estimated by fitting Cox proportional hazards models with follow-up through 2007. Compared with never smokers, ever smokers had a 1.11-fold (95% confidence interval (CI): 0.94, 1.30) higher NHL risk that increased to a 1.22-fold (95% CI: 0.95, 1.57) higher risk when women with household passive smoking were excluded from the reference category. Statistically significant dose responses were observed for lifetime cumulative smoking exposure (intensity and pack-years; both P 's for trend = 0.02) when women with household passive smoking were excluded from the reference category. Among never smokers, NHL risk increased with increasing lifetime exposure to passive smoking (relative risk = 1.51 (95% CI: 1.03, 2.22) for >40 years vs. ≤5 years of passive smoking; P for trend = 0.03), particularly for follicular lymphoma (relative risk = 2.89 (95% CI: 1.23, 6.80); P for trend = 0.01). The present study provides evidence that smoking and passive smoking may influence NHL etiology, particularly for follicular lymphoma.

Risk factors for non-Hodgkin lymphoma subtypes defined by histology and t(14;18) in a population-based case-control study

The t(14;18) chromosomal translocation is the most common cytogenetic abnormality in non-Hodgkin lymphoma (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 (third tertile vs. first 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+ vs. 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.

A case-control study of tobacco use and other non-occupational risk factors for lymphoma subtypes defined by t(14; 18) translocations and bcl-2 expression

OBJECTIVE

We re-evaluated reported associations between tobacco use and other factors and non-Hodgkin lymphoma (NHL) t(14; 18)-subtypes based on fluorescence in situ hybridization (FISH) assays believed to be more sensitive than polymerase chain reaction (PCR), previously used for detecting t(14; 18).

METHODS

Commercial FISH assays and bcl-2 immunostaining were performed on paraffin sections to determine t(14; 18) and bcl-2 case-subtypes. Polytomous logistic regression models estimated associations between NHL case-subtypes (versus 1,245 population-based controls) and tobacco use as well as other factors.

RESULTS

Adjusting for age, state, and proxy status, t(14; 18)-negative NHL was associated with any tobacco use (vs. no tobacco use, OR = 1.9, 95% CI = 1.0-3.5), including current smoking (vs. no cigarette use, OR = 1.9, 95% CI = 1.1-3.2). Tobacco exposures were not clearly associated with t(14; 18)-positive NHL or bcl-2 case-subtypes. Hair-dye use and family history of a hemolymphatic cancer were associated with t(14; 18)-negative NHL, but the number of exposed cases was small.

CONCLUSIONS

The association between t(14; 18)-negative NHL and cigarette smoking was unexpected given previous evidence of associations between smoking and follicular lymphoma (which is largely t(14; 18)-positive). Future studies characterizing additional molecular characteristics of t(14; 18)-negative NHL may help determine whether the association with smoking may have been causal versus an artifact of chance or bias.

Genetic variation in N-acetyltransferases 1 and 2, cigarette smoking, and risk of non-Hodgkin lymphoma

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 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. Of the 535 controls, 53.1% reported ever smoking, and of the 461 cases, 55.7% reported ever smoking. We found a two-fold increased risk of T-cell lymphoma among those possessing the NAT1*10 genotype compared to those with other NAT1 genotypes; including 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), though these results were based on a small number of cases. When smoking status and risk of NHL was stratified by NAT1 and NAT2 genotypes, an increased risk of NHL overall was observed in current (OR = 1.7; 95% CI: 1.2-2.4) smokers without the NAT1*10 genotype but not among smokers with the NAT1*10 genotype (p-interaction < 0.01). No association between history of cigarette smoking and risk of NHL overall was observed with any NAT2 genotype. Our results present modest evidence that acetylation rate is associated with risk of NHL for specific subtypes and that the NAT1*10 genotype is an "at-risk" allele. Additionally, our results suggest that the relationship between NHL and smoking status may be modified by common genetic variation in NAT1 but not NAT2. We conclude that these findings require replication in larger studies and ultimately in pooled analyses.

Parental smoking and childhood leukemia

Childhood leukemia is the most common cancer among children, representing 31% of all cancer cases occurring in children younger than the age of 15 years in the USA. There are only few known risk factors of childhood leukemia (sex, age, race, exposure to ionizing radiation, and certain congenital diseases, such as Down syndrome and neurofibromatosis), which account for only 10% of the childhood leukemia cases. Several lines of evidence suggest that childhood leukemia may be more due to environmental rather than genetic factors, although genes may play modifying roles. Human and animal studies showed that the development of childhood leukemia is a two-step process that requires a prenatal initiating event(s) plus a postnatal promoting event(s). Despite a substantial public health effort to reduce cigarette smoking, a large proportion of the US and world population still smoke. Tobacco smoke contains at least 60 known human or animal carcinogens, with the major chemical classes being volatile hydrocarbons, aldehydes, aromatic amines, polycyclic aromatic hydrocarbons, and nitrosamines; among these chemicals, only benzene is an established leukemogen, although other chemicals in the tobacco could interact with one another in a complex way to jointly attain a significant carcinogenic effect on the development of leukemia. Although tobacco smoke is an established risk factor for adult myeloid leukemia, the studies of association between parental smoking and childhood leukemia have produced inconsistent results. The majority of the studies on maternal smoking and childhood leukemia did not find a significant positive association and some even reported an inverse association. In contrast to studies of maternal smoking, studies of paternal smoking and childhood leukemia reported more positive associations but only by less than half of the studies. Future directions to be considered for improving the study of parental smoking and childhood leukemia are: 1) consider all sources of benzene exposure in addition to smoking, including occupational exposure and traffic exhausts; 2) childhood leukemia is a heterogeneous disease and epidemiologic studies of childhood leukemia can be greatly improved by grouping childhood leukemia into more homogeneous groups by molecular techniques (e.g., structural and numerical chromosomal changes); and 3) assess gene-environment interaction. It is hoped that through the continual effort, more will be uncovered regarding the causes of childhood leukemia. In the meantime, more effort should be spent on educating the parents to quit smoking, because parental smoking is known to affect many childhood diseases (e.g., asthma, respiratory tract infection, and otitis media) that are much more prevalent than childhood leukemia.

Chronic lymphocytic leukaemia: an overview of aetiology in light of recent developments in classification and pathogenesis

This overview of the epidemiology of chronic lymphocytic leukaemia (CLL) summarizes the evolution of classification and coding systems and describes the intersection of pathogenesis and aetiology. The role of the putative precursor to CLL, monoclonal B-cell lymphocytosis (MBL), is considered, and ideas for future investigations of the MBL-CLL relationship are outlined. We discuss the epidemiology of CLL, focusing on descriptive patterns and methodological considerations. Postulated risk factors are reviewed including the role of ionizing and non-ionizing radiation, occupational and environmental chemical exposures, medical conditions and treatments, and lifestyle and genetic factors. We conclude by raising key questions that need to be addressed to advance our understanding of CLL aetiology. Recommendations for future epidemiological studies are given, including the standardization of reporting of CLL across cancer registries, the clarification of the natural history of MBL, and the circumvention of the methodological shortcomings of prior epidemiological investigations in relation to radiation, chemical exposures and infectious agents.

Chronic lymphocytic leukaemia and small lymphocytic lymphoma: overview of the descriptive epidemiology

The 2001 World Health Organization classification scheme considers B-cell chronic lymphocytic leukaemia (CLL) and small lymphocytic lymphoma (SLL) in an aggregate category (CLL/SLL) because of shared clinicopathological features. We have estimated age-adjusted incidence rates (IRs) of CLL and SLL in the population-based Surveillance, Epidemiology and End Results Program in the United States to analyse patterns of CLL and SLL separately and jointly. Age-standardized to the 2000 US population, overall IRs were 3.83 per 100 000 person-years for CLL (n = 15 676) and 1.31 for SLL (n = 5382) during 1993-2004. Incidence of the combined entity, CLL/SLL, was 90% higher among males compared to females, and the male:female IR ratio was significantly higher for CLL (1.98) than for SLL (1.67). CLL/SLL IRs were 25% and 77% lower among Blacks and Asian/Pacific Islanders, respectively, compared to Whites. A significant reporting delay was evident for CLL but not for SLL, so that CLL/SLL temporal trends must be interpreted cautiously. CLL and SLL IRs increased exponentially with age among all gender/race groups, with CLL IRs increasing more steeply with advancing age than SLL. Avenues of future research include assessment of delayed- and under-reporting to cancer registries and exploration of race, gender, and age effects in epidemiological studies.

Cigarette smoking and risk of Hodgkin lymphoma: a population-based case-control study

BACKGROUND

Studies have inconsistently reported an association between tobacco smoking and Hodgkin lymphoma (HL) risk. The conflicting finding may reflect etiologic heterogeneity between HL subtypes, warranting further characterization of the relationship.

METHODS

We collected information on tobacco-smoking habits in 586 classic HL cases and 3,187 population controls in a Danish-Swedish case-control study. HL EBV status was established for 499 cases by standard techniques. Odds ratios (OR) for an association with cigarette smoking were calculated by logistic regression for HL overall and stratified by age, sex, major histology subtypes, and tumor EBV status, adjusting for known confounders.

RESULTS

Compared with never smokers, current cigarette smokers were at an increased overall HL risk [adjusted OR, 1.57; 95% confidence interval (95% CI), 1.22-2.03]. The association was strongest for EBV-positive HL (adjusted OR, 2.36; 95% CI, 1.51-3.71), but also applied to EBV-negative HL (adjusted OR, 1.43; 95% CI, 1.05-1.97; P(homogeneity EBV-pos) versus P(homogeneity EBV-neg) = 0.04). The association did not vary appreciably by age, sex, or histologic subtype, the apparent EBV-related difference present in all strata. There was no evidence of a dose-response pattern, whether by age at smoking initiation, daily cigarette consumption, number of years smoking, or cumulative number of cigarettes smoked. Similar results were obtained in analyses using non-HL patients (n = 3,055) participating in the founding study as comparison group.

CONCLUSION

The observed association between cigarette smoking and HL risk is consistent with previous findings and biologically credible. Although not easily dismissed as an artifact, the limited evidence of a dose-response pattern renders the overall evidence of causality weak.

Temporal patterns of association between cigarette smoking and leukemia risk

OBJECTIVES

To evaluate variation in smoking-related leukemia risk with time-since-exposure.

METHODS

We analyzed data from a population-based case-control study conducted in Germany. Odds ratios were estimated by applying conditional logistic regression methods to 470 incident leukemia cases and 1,009 controls. Cases were classified as acute non-lymphocytic leukemia (ANLL), acute lymphocytic leukemia (ALL), chronic myeloid leukemia (CML), and chronic lymphocytic leukemia (CLL). Temporal variation in the impact of smoking on leukemia risk was assessed via exposure time-windows and a spline latency function.

RESULTS

Current smokers were at greater risk of ANLL than those who never smoked (OR = 1.65 95% CI: 0.95, 2.87) and a positive trend was observed in ANLL risk with cumulative pack-decades smoked, under a 2-year exposure lag assumption (OR/pack-decade = 1.11 95% CI: 0.96, 1.30). This was primarily due to the association between ANLL and smoking in the period 2 to <10 years prior (OR/pack-decade = 2.72 95% CI: 0.93, 7.99). There was minimal evidence of association between ANLL risk and packs smoked 10 or more years prior. CML and ALL exhibited minimal evidence of association with smoking status. CLL exhibited a positive association with smoking in the periods 2 to <10 years and 10 to <20 years prior to diagnosis although estimates of association were highly imprecise.

CONCLUSIONS

The temporal pattern of smoking-induced ANLL risk appears to follow a prompt peak in excess incidence that diminishes with time since exposure.

Tobacco use, body mass index, and the risk of leukemia and multiple myeloma: a nationwide cohort study in Sweden

In a prospective cohort study of more than 330,000 Swedish construction workers, we explored the effect of tobacco smoking, oral moist snuff use, and body mass index (BMI) on the risk of developing leukemia (excluding chronic lymphocytic leukemia) and multiple myeloma (MM). Study subjects were participants of a health surveillance system within the building industry. Record linkage to the nationwide Swedish cancer registry, migration registry, and cause of death registry made a comprehensive follow-up available. A total of 372 incident cases of leukemia and 520 subjects with MM was ascertained. An increase in risk of acute myelogenous leukemia (AML) was observed in current smokers (incidence rate ratio, 1.50; 95% confidence interval, 1.06-2.11). Furthermore, there was an indication of a possible association between smoking intensity and risk of acute lymphocytic leukemia. Results on snuff use as well as BMI showed no association. This study confirms the role of smoking as a risk factor for AML and gives no support to the hypothesis of a role of snuff use or BMI level on the risk of leukemia or MM.

Case-control study of lymphoid neoplasm in three French areas: description, alcohol and tobacco consumption

A multi-centre hospital-based case-control study was conducted in three regions of France between 2000 and 2003 in order to establish the risk factors of lymphoid neoplasms. We report here results concerning alcohol and tobacco consumption. A total of 298 cases and 276 controls, case-matched by inclusion centre, age and sex were included. Cases were classified according to the World Health Organization classification and validated by an expert panel of eight pathologists. Overall alcohol intake did not incur any risk increase for non-Hodgkin's lymphoma. Wine consumption marginally increased the risk of follicular lymphoma [odds ratio=2.19 (0.83-5.80)], with a higher risk for drinkers who started before the age of 20 years [odds ratio=4.04 (1.19-13.76)] and for drinkers who consumed more than 19 g of alcohol per day [odds ratio=4.37 (1.04-18.45)]. Beer and spirit consumption was not linked to non-Hodgkin's lymphoma risk. Tobacco consumption did not show a risk increase. The risk increase of follicular lymphoma due to wine consumption was new. We discuss this risk based on the French context, France being the European country with the highest alcohol consumption, particularly of wine.

The non-Hodgkin lymphomas: a review of the epidemiologic literature

The non-Hodgkin lymphomas (NHL) are a heterogeneous group of B-cell and T-cell neoplasms that arise primarily in the lymph nodes. NHL incidence rates in the US doubled between about 1970 and 1990, and stabilized during the 1990s. NHL accounts for approximately 3.4% of cancer deaths in the US. Although some of the observed patterns in NHL have been related to HIV/AIDS, these conditions cannot fully explain the magnitude of the changes; neither do changes in classification systems nor improved diagnostic capabilities. Studies of occupational and environmental exposures (e.g., pesticides, solvents) have produced no consistent pattern of significant positive associations. Inverse associations with ultraviolet radiation exposure and alcohol and fish intake, and positive associations with meat and saturated fat intake have been reported in several studies; additional studies are needed to confirm or refute these associations. Family history of NHL or other hematolympho-proliferative cancers and personal history of several autoimmune disorders are associated with increased risk of NHL, but are not likely to account for a large proportion of cases. HIV and other infectious agents, such as human herpesvirus 8 and Epstein-Barr, appear to be associated with differing types of NHL, such as some B-cell lymphomas. Future epidemiologic studies should evaluate associations by NHL type, enhance exposure information collected, and elucidate factors that may identify susceptible (or resistant) subpopulations because of genetic, immunologic or other characteristics. The extent to which the etiology of NHL types may differ is important to resolve in ongoing and future studies.

Alcohol consumption and risk of leukemia: A multicenter case–control study

A population-based case-control study of 649 leukemia cases and 1771 controls carried out in 11 Italian areas, offered the opportunity to evaluate the relationship between alcohol consumption and leukemia risk. For all leukemias, acute lymphocytic leukemia (ALL), acute myeloid leukemia (AML), and chronic lymphocytic leukemia (CLL), we found a non-significantly inverse association for moderate levels of total alcohol and wine intake, but increased risks at high levels, with, in most cases, significant trend effects (odd ratios (OR) for all leukemias in the lowest quartile of total alcohol consumption [0.1-9.0 g/day of ethanol] versus never-drinker = 0.73; 95% confidence intervals (95% CI) = 0.51-1.03; OR in the highest quartile [> 31.7 g/day] = 1.15; 95% CI = 0.82-1.63; p of the linear trend test = 0.007). For chronic myeloid leukemia (CML), we found a non-significantly positive association for all levels of total alcohol and wine intake, and a significant positive linear trend effect (p = 0.03) for wine intake (OR for 0.1-9.0 g/day of ethanol intake from wine = 1.34; 95% CI = 0.61-2.94; OR in the highest quartile of wine intake [> 27.7 g/day] = 2.13; 95% CI = 1.01-4.50). No consistent dose-response was detected analysing duration of alcohol consumption for any leukemia subtypes. In conclusion, even though our study did not show a clear association between alcohol intake and leukemia risk, some of the patterns of the risk estimates (a possible J-shaped dose-response curve between alcohol intake and ALL, AML, and CLL risks, and the positive association between alcohol and CML), may be suggestive.

Does smoking or alcohol modify the risk of Epstein-Barr virus-positive or -negative Hodgkin lymphoma?

BACKGROUND

The aim was to investigate whether 2 subgroups of Hodgkin lymphoma (Epstein-Barr virus-positive and Epstein-Barr virus-negative) are associated with smoking or alcohol.

METHODS

Patients with lymphoma diagnosed between age 16 and 69 years in geographically defined areas of England were recruited between 1998 and 2003. One control, matched to each lymphoma case on sex, date of birth, and area of residence, was randomly selected from population registers. Self-reported histories of tobacco and alcohol use were collected during face-to-face interviews with cases and controls.

RESULTS

Compared with lifelong nonsmokers, ever-smokers were at increased risk of Hodgkin lymphoma (odds ratio =1.4; 95% confidence interval = 1.1-1.9). This excess was among current smokers, defined as smoking 2 years before diagnosis (1.7; 1.2-2.3). An increasing trend was observed with rising numbers of years smoked. Risks fell as the number of years stopped smoking increased, becoming equivalent to that of a nonsmoker 10 or more years after quitting. Associations were suggested for Epstein-Barr virus-positive Hodgkin lymphoma, but less so for Epstein-Barr negative Hodgkin lymphoma. No associations between Hodgkin lymphoma and alcohol consumption were observed.

CONCLUSIONS

The association between smoking and Hodgkin lymphoma in general, and Epstein-Barr-positive Hodgkin lymphoma in particular, is consistent with previous studies. Further exploration of the relationship between Hodgkin lymphoma and smoking and of the potential mechanisms by which smoking could interact with Epstein-Barr virus status to increase Hodgkin lymphoma risk are required.

Multiple myeloma: A review of the epidemiologic literature

Multiple myeloma, a neoplasm of plasma cells, accounts for approximately approximately 15% of lymphatohematopoietic cancers (LHC) and 2% of all cancers in the US. Incidence rates increase with age, particularly after age 40, and are higher in men, particularly African American men. The etiology is unknown with no established lifestyle, occupational or environmental risk factors. Although several factors have been implicated as potentially etiologic, findings are inconsistent. We reviewed epidemiologic studies that evaluated lifestyle, dietary, occupational and environmental factors; immune function, family history and genetic factors; and the hypothesized precursor, monoclonal gammopathies of undetermined significance (MGUS). Because multiple myeloma is an uncommon disease, etiologic assessments can be difficult because of small numbers of cases in occupational cohort studies, and few subjects reporting exposure to specific agents in case-control studies. Elevated risks have been reported consistently among persons with a positive family history of LHC. A few studies have reported a relationship between obesity and multiple myeloma, and this may be a promising area of research. Factors underlying higher incidence rates of multiple myeloma in African Americans are not understood. The progression from MGUS to multiple myeloma has been reported in several studies; however, there are no established risk factors for MGUS. To improve our understanding of the causes of multiple myeloma, future research efforts should seek the causes of MGUS. More research is also needed on the genetic factors of multiple myeloma, given the strong familial clustering of the disease.

Expression of DNA mismatch repair proteins in transformed non-Hodgkin's lymphoma: relationship to smoking

It has been hypothesized that defects in DNA-mismatch repair are associated with smoking in certain types of transformed non-Hodgkin lymphoma (NHL). We have analyzed biopsy samples from two indolent B-cell lymphomas, follicular lymphoma (FL) and chronic lymphocytic leukemia/small lymphocytic leukemia (CLL/SLL), that have transformed to diffuse-large B-cell lymphoma (DLBCL). We correlated the presence or absence of DNA-mismatch repair enzymes by immunostaining as well as the p53 status to smoking history. Of all patients (n = 30), 37% showed negative immunostaining of MLH1, 16% showed negative immunostaining of MSH2 and 63% had p53 mutations and/or protein expression. Eighteen out of 20 transformed follicular lymphomas and seven out of 10 CLL/SLL that have transformed to DLBCL (Richter's syndrome) were informative for smoking histories. We found that the relative risk of negative immunostaining for either MLH1 or MSH2 was 2.2 times higher in smokers than non-smokers (relative risk = 2.2041, 95% confidence interval: 0.89714, 5.41491). No direct correlation was found between smoking and the mutations in the p53 gene. These results suggest that cigarette smoking may play a role in the development of transformed lymphomas through defective mismatch repair.

Alcohol consumption and risk of Hodgkin's lymphoma and multiple myeloma: a multicentre case-control study

BACKGROUND

Few studies have analysed the association between alcohol intake and Hodgkin's lymphoma (HL) or multiple myeloma (MM) risks.

MATERIALS AND METHODS

A multicentre population-based case-control study of 363 HL, 270 MM cases, and 1771 controls offered the opportunity to evaluate the relationship between alcohol and HL/MM risks. Unconditional logistic regression was carried out to estimate odds ratios (ORs) and 95% confidence intervals (CIs), associated with alcohol intake (servings per week, grams per day of ethanol intake) or duration of exposure (year).

RESULTS

For HL, considering nonsmokers only, ever drinkers had a significantly decreased risk than never drinkers (OR=0.46). Significantly lower risks in all levels of total alcohol intake were also detected, considering servings per week (OR for one to four servings per week=0.51, 95% CI 0.32-0.82; OR for five to nine servings per week=0.39, 95% CI 0.21-0.73; OR for 10-19 servings per week=0.26, 95% CI 0.12-0.54; OR for >or=20 servings per week=0.34, 95% CI 0.15-0.79) and grams per day of ethanol intake (OR for 0.1-9.0 g/day=0.45, 95% CI 0.27-0.74; OR for 9.1-17.9 g/day=0.52, 95% CI 0.30-0.90; OR for 18.0-31.7 g/day=0.27, 95% CI 0.13-0.57; OR for >31.7 g/day=0.35, 95% CI 0.15-0.79). In the analysis for ever-smoking HL cases and controls, ever drinkers had the same risk as never drinkers. For MM, ever drinkers had a non-significantly decreased risk than non-drinkers (OR=0.74), and ORs in almost all consumption levels were not significant (OR for 0.1-9.0 g/day=0.93; OR for 9.1-17.9 g/day=0.82; OR for 18.0-31.7 g/day=0.47; 95% CI 0.28-0.81; OR for >31.7 g/day=0.68). For HL and MM, the beverage type did not affect the risk significantly, and no consistent dose-response relationships were found, considering intensity or duration of alcohol consumption.

CONCLUSIONS

Our study indicates a protective effect of alcohol consumption for nonsmoking HL cases.

Tobacco smoking, alcohol drinking and Hodgkin's lymphoma: a European multi-centre case-control study (EPILYMPH)

We analysed the effects of tobacco and alcohol in the aetiology of Hodgkin's lymphoma (HL), based on 340 cases and 2465 controls enrolled in Spain, France, Italy, Germany, Ireland and Czech Republic, between 1998 and 2004. Current smokers showed a significantly increased odds ratio (OR) of HL of 1.39 (95% confidence interval (CI) = 1.04-1.87). Analyses were also conducted separately for subjects younger than 35 years (179 cases) and for older subjects (161 cases). For subjects below age 35, no association was observed between tobacco and HL, whereas for older subjects, ever-smokers experienced a doubled risk of HL as compared to never smokers and the OR of HL for current smoking was 2.35 (95% CI = 1.52-3.61), with suggestion of a dose-response relationship. A protective effect of alcohol was observed in both age groups. The OR for ever-regular drinking was 0.58 (95% CI = 0.38-0.89) for younger subjects and 0.50 (95% CI = 0.34-0.74) for older subjects. There was no evidence of interaction between tobacco and alcohol. Our results are consistent with previous studies, suggesting a protective effect of alcohol on HL. An effect of tobacco was suggested for HL occurring in middle and late age, although this finding might have occurred by chance.

Cigarette smoking and alcohol consumption as determinants of survival in non-Hodgkin's lymphoma: a population-based study

BACKGROUND

The risk of non-Hodgkin's lymphoma (NHL) seems to be enhanced by cigarette smoking and lowered by alcohol drinking.

PATIENTS AND METHODS

To assess whether cigarette smoking and alcohol drinking affect NHL survival, a population-based prospective study on 1138 Italian patients, diagnosed in 1991-1993, followed-up until 2002, was carried out. At diagnosis, clinical and socio-demographic data were recorded and lifestyle habits were assessed through a validated questionnaire. Survival analysis was performed with Kaplan-Meier methods. Hazard ratios (HR) were estimated by Cox regression.

RESULTS

The mean follow-up was 6.6 years (standard deviation (SD) 4.3). The mean survival time was 7.56 years (SD 0.155). At both univariate and multivariate analysis heavy cigarette smoking and alcohol drinking were associated with poor survival. Compared with those with a lower cumulative exposure to tobacco smoking, those who had smoked>31 pack-years had a worse survival (HR=1.60, 95%CI=1.18-2.18). Drinkers had a higher risk of death compared with non-drinkers (HR=1.41, 95%CI=1.10-1.81). Considering only those who had NHL as cause of death, the HR for the higher category of pack-years smoked, compared with the lowest, was 1.63 (95% CI=1.15-2.33) and for drinkers, compared with non-drinkers, it was 1.33 (95% CI=1.01-1.80).

CONCLUSIONS

cigarette smoking and alcohol drinking may influence NHL survival.

Tobacco use, body mass index and the risk of malignant lymphomas--a nationwide cohort study in Sweden

In the search for risk factors involved in the etiology of lymphoproliferative malignancies there is still inconsistent evidence regarding effects of smoking tobacco, and the role of smokeless tobacco is poorly investigated. New evidence indicates that excess body weight increases the risk of NHL and HD. To determine if tobacco use of various forms and high Body Mass Index (BMI) affect the occurrence of these neoplasms, we conducted a prospective cohort study on over 330,000 Swedish construction workers included in the Construction Industry Working Environment and Health program. Information on smoking, snuff dipping, height and weight was gathered by self administered questionnaires together with personal interviews. Cancer incidence was ascertained through the year 2000 by record linkage to the nationwide Swedish Cancer Registry, Migration Registry and Cause of Death Registry. At the end of follow up, 1,309 subjects had been diagnosed with NHL (including chronic lymphocytic leukemia) and 205 with HD respectively. Age adjusted incidence rate ratios were computed using Cox proportional Hazard regression modeling. Smoking cigarette, pipe or cigar was not associated with NHL or HD. There was no evidence indicating a relation between quantity and duration of smoking and NHL or HD risk. No link was found between NHL and usage of smokeless tobacco. Having a BMI of 30 or higher did not convey excess risk of developing NHL or HD compared to normal weight (BMI 18.6-24.9). We conclude that tobacco smoking and high BMI do not entail an increased risk of NHL and HD. Our findings of a relation between the duration of snuff dipping and HD need further investigation.

Tobacco and alcohol consumption and risk of lymphoma: Results of apopulation-based case-control study in Germany

Changing trends in lifestyle exposures are suggested to be contributing factors to the increasing incidence rates for lymphoma. We investigated the relationship between smoking and alcohol consumption and the risk of lymphoma among adult participants of a population-based case-control study recently conducted in Germany. In 710 case-control pairs, an increased risk of lymphoma was associated with a long duration of smoking (p for trend = 0.01 for men) and smoking of > 20 cigarettes per day(OR = 2.7; 95% CI = 1.4-5.2 for women). Elevated odds ratios were seen for most lymphoma subentities, albeit mostly without reaching statistical significance. A strong association was evident between smoking and multiple myeloma (OR = 2.4, 95% CI = 0.98-5.74 for men; OR = 2.9, 95% CI = 1.1-7.4 for women) and Hodgkin's lymphoma among men (OR = 3.6; 95% CI = 1.7-7.5). Alcohol consumption 10 years prior to the date of interview appeared to decrease the risk of lymphoma. Odds ratios for men who reported alcohol consumption were 53% lower (95% CI = 0.31-0.71) compared to men who drank very little or no alcohol. The same tendency was evident for women, although the association was less pronounced. The inverse relationship was also seen for low amounts of alcohol and did not appear to be restricted to specific types of beverages. Although biologic rationale for a protective effect of alcohol consumption may be given, a more in-depth analysis involving genetic markers is indicated to clarify if ethanol, other components in alcoholic beverages, or factors associated with moderate drinking reduce lymphoma risk among adults. In conclusion, this investigation suggests a positive association between tobacco smoking and lymphoma risk and finds decreased odds ratios among consumers of alcohol.

Life-style and environmental factors in the development of nasal NK/T-cell lymphoma: A case–control study in East Asia

Cases of nasal NK/T-cell lymphoma (NKTCL) occur occasionally in Asian and Latin American countries but rarely in Western countries. The etiological role of life-style and environmental factors in nasal NKTCL was investigated. Five university hospitals in Japan and one each in Korea and China participated in this study; a total of 88 cases and 305 hospital controls were accrued during 2000-2005. The odds ratio (OR) of NKTCL obtained after adjustments of age, sex and country was 4.15 (95% confidence interval (CI), 1.74-9.87) for farmers, 2.81 (CI, 1.49-5.29) for producers of crops, 4.01 (CI, 1.99-8.09) for pesticide users, 11.65 (CI, 1.17-115.82) for residents near garbage burning plants, 2.95 (CI, 1.25-6.95) for former drinkers, and 0.49 (CI, 0.23-1.04) for current smokers. The ORs for crop producers, who minimized their exposure to pesticides by using gloves and glasses, and sprinkling downwind at the time of pesticide use, were 3.30 (95% CI, 1.28-8.54), 1.18 (95% CI, 0.11-12.13) and 2.20 (95% CI, 0.88-5.53), respectively, which were lower than those for producers who did not take these precautions. Exposure to pesticides and chemical solvents could be causative of NKTCL. Taken together, life-style and environmental factors might be risk factors for NKTCL.

Lifestyle factors and the risk of adult leukemia in Canada

OBJECTIVES

To evaluate the impact of active smoking, obesity, and dietary intakes on the risk of adult leukemia.

METHODS

We analysed data obtained from a population-based case-control study conducted in eight Canadian provinces. Risk estimates were generated by applying multivariate logistic regression methods to 1068 incident histologically confirmed leukemia cases and 5039 controls aged 20-74.

RESULTS

We found a statistically significant increased risk for acute myeloid leukemia (AML) associated with active smoking, with a clear dose-response relationship and an adjusted odds ratio (OR) of 1.5 (95% confidence interval [CI]=1.1-2.0) for heavy smokers reporting more than 20 pack-years of cigarette smoking. We also observed positive associations with the highest body mass index (BMI) for AML, chronic myeloid leukemia, and chronic lymphoid leukemia with a significant dose-response relationship. No association with leukemia was observed for the intake of fruits and vegetables, and the effect of active smoking on adult leukemia risk was not modified by fruits and/or vegetables consumption or obesity. However, the positive risk for AML associated with active smoking disappeared among subjects with high BMI (> or =30 kg/m2).

CONCLUSIONS

Our study contributes to the accumulating evidence linking AML and active smoking, and provides some evidence that obesity increases the risk of most of the adult leukemia subtypes.

Tobacco use and non-Hodgkin lymphoma: results from a population-based case-control study in the San Francisco Bay Area, California

OBJECTIVE

Investigate the association between tobacco use and non-Hodgkin lymphoma (NHL).

METHODS

Tobacco-use data were collected during in-person interviews in a population-based case-control study of NHL (N=1593 patients, N=2515 controls) conducted in the San Francisco Bay Area between 1988 and 1995. Odds ratios (ORs) for HIV-negative participants were obtained from adjusted unconditional logistic regression models stratified by sex.

RESULTS

NHL was not associated with overall tobacco use, intensity or duration of cigarette smoking in women or men. However, ORs were increased for NHL among men who used any non-cigarette tobacco alone (OR=1.7), non-cigarette tobacco and cigarettes (OR=1.4), multiple types of non-cigarette tobacco alone (OR=2.1) and smokeless tobacco alone (OR=4.0). In analyses stratified by sex and age, ORs for NHL associated with cigarette smoking in general were above unity among those aged > or =60 years. ORs for follicular lymphoma were increased in men who used cigarettes and other tobacco, cigars alone and smokeless tobacco alone. Diffuse large-cell lymphoma in men was associated with use of cigarettes and other tobacco, and multiple types of non-cigarette tobacco.

CONCLUSION

Our data do not support an association between overall tobacco use and all NHL in women or men. Further analyses are warranted in larger studies to evaluate non-cigarette tobacco use, tobacco-related biologic markers and genetic factors in the development of NHL.

Cigarette smoking and risk of non-Hodgkin's lymphoma--a population-based case-control study

BACKGROUND

Epidemiologic evidence of an association between tobacco smoking and non-Hodgkin's lymphoma has been conflicting. This may reflect that non-Hodgkin's lymphoma comprises several distinct disease entities with different etiologies, as some studies have indicated an association between smoking and follicular lymphoma.

OBJECTIVE

To investigate the association between cigarette smoking and non-Hodgkin's lymphoma risk, overall and by subtype.

METHODS

As part of a nationwide Danish-Swedish population-based case-control study, we interviewed 3,055 incident non-Hodgkin's lymphoma patients and 3,187 population controls. All lymphomas were uniformly classified according to the WHO classification. We used unconditional logistic regression to estimate adjusted odds ratios (OR) and 95% confidence intervals (95% CI) for the association between cigarette smoking and risk of non-Hodgkin's lymphoma.

RESULTS

Cigarette smoking was not associated with the risk of non-Hodgkin's lymphoma overall (OR, 0.97; 95% CI, 0.87-1.08) nor with the major subgroups such as diffuse large B-cell lymphoma (OR, 0.94; 95% CI, 0.79-1.10), chronic lymphocytic leukemia (OR, 0.86; 95% CI, 0.72-1.02), or follicular lymphoma (OR, 1.03; 95% CI, 0.85-1.24). Female smokers were at a marginally increased risk of follicular lymphoma (OR, 1.41; 95% CI, 1.04-1.92). Men who had ever smoked had a significantly increased risk of T-cell lymphoma (OR, 1.67; 95% CI, 1.11-2.51). No dose-response association with cigarette smoking could be established for any lymphoma subgroup.

CONCLUSION

We found little evidence of an association between cigarette smoking and non-Hodgkin's lymphoma risk overall. Although increased risks of follicular lymphoma in female smokers and of T-cell lymphoma in male smokers were suggested, no dose-response relationship was observed, leaving limited support for causality.

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 Burkitt's 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.

Psychosocial function after hematopoietic stem cell transplantation

The authors report on a prospective cohort study of patients with chronic myelogenous leukemia undergoing allogeneic hematopoietic stem cell transplantation. The purpose was to evaluate the progression of quality of life and mood, as well as patterns of alcohol consumption, a behavior with potential adverse health consequences. Of the 84 subjects who completed serial measures and other interviews at admission for hematopoietic stem cell transplantation and 6-month follow-up, 75 provided data 12 months later The main findings of this study were that quality of life improves, measures of depressive symptoms decline, and patients drink less alcohol overall. Time was the most important variable accounting for these changes.

Smoking and non‐Hodgkin lymphoma: Case‐control study in Italy

Tobacco smoking is a well-documented risk factor for several cancers, but the role of cigarette smoking in the etiology of non-Hodgkin lymphoma (NHL) is inadequately understood. Hepatitis C virus (HCV) has been associated with NHL, but the interaction between HCV and smoking habits has not yet been studied. Between 1999 and 2002, we conducted a case-control study on the association of HCV, smoking habits and NHL in 2 areas of northern and southern Italy. Cases were 225 consecutive patients (median age, 59 years) with a new diagnosis of NHL that were admitted to reference and general hospitals. Controls were 504 patients (median age, 63 years) admitted to the same hospitals as cases, for a wide spectrum of acute, nonneoplastic, nonimmune-, nor tobacco-related conditions. Current, heavy smokers (> or = 20 cigarettes/day) had an odds ratio (OR) of NHL of 2.10 (95% confidence interval, CI: 1.07-4.12) compared to never smokers. The association between smoking and NHL was consistent across strata of sex and age. Compared to never smokers, current smokers of > or = 20 cigarettes/day had ORs of 1.14 (95% CI: 0.37-3.56) for B-cell-low-grade, 2.10 (95% CI: 0.94-4.67) for B-cell-intermediate and high-grade, and 25.84 (95% CI: 1.95-342.17) for T-cell NHL. The effect of tobacco smoking and HCV were independent on the relative risk, leading a 4-fold elevated risk in current smokers HCV positive subjects. Tobacco smoking and hepatitis C virus (HCV) have been associated to non-Hodgkin lymphoma (NHL), but the interaction between HCV and smoking habits has not yet been studied. Our study confirms that tobacco is related to NHL, and reports on the combined effect of tobacco smoking and HCV. Infection acted together according to a multiplicative model, leading to a 4-fold elevated risk in current smokers HCV positive subjects.

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 (> or = 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.