Physical activity, obesity, energy intake, and the risk of non-Hodgkin's lymphoma: a population-based case-control study

Lifetime occupational and recreational physical activity and risk of lymphoma subtypes. Results from the European Epilymph case-control study

Physical activity is known to convey protection against several cancers. However, results on the risk of lymphoma overall and its subtypes have been inconsistent. The aim of this study was to investigate occupational and recreational physical activity in relation to risk of lymphoma subtypes adjusting for established occupational risk factors. We applied standardized tools to assess energy expenditure at work and in recreational physical activities to the questionnaire information on lifetime work and exercise history in 1117 lymphoma cases, including Hodgkin lymphoma, and B-cell (including chronic lymphocytic leukemia, and multiple myeloma) and T-cell non-Hodgkin's lymphoma (NHL) subtypes, and 1207 controls who took part in the multicentre European EpiLymph case-control study. We calculated the risk of lymphoma (all subtypes), B-cell NHL and its most represented subtypes, and Hodgkin's lymphoma (all subtypes) associated with weekly average Metabolic Equivalent of Task (MET-hours/week) and cumulative MET-hours of lifetime recreational, occupational, and total physical activity, with unconditional logistic regression and polytomous regression analysis adjusting by age, centre, sex, education, body mass index, history of farm work and solvent use. We observed an inverse association of occupational, and total physical activity with risk of lymphoma (all subtypes), and B-cell non-Hodgkin's lymphoma among women, and an upward trend in risk of Hodgkin's lymphoma with recreational and total physical activity among men, for which we cannot exclude chance or bias. Our results suggest no effect of overall physical activity on risk of lymphoma and its subtypes.

Physical activity and the risk of non-Hodgkin lymphoma subtypes: A pooled analysis

Non-Hodgkin lymphoma (NHL) is composed of a heterogeneous collection of subtypes with considerable differences in genetics, biology and aetiology. Studies to date on physical activity and NHL risk have not had sufficient sample size to evaluate whether associations differ by subtype. We pooled data from nine case-control studies to examine the association between moderate-to-vigorous intensity physical activity (MVPA) and risk of NHL overall and by subtype (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukaemia/small lymphocytic lymphoma, marginal zone lymphoma and mature T-cell lymphoma). A total of 5653 cases and 9115 controls were included in the pooled analysis. Physical activity was harmonised across nine studies and modelled as study-specific tertiles. Multinomial logistic regression was used to estimate the association between physical activity and NHL, adjusting for confounders. The overall odds of NHL was 13% lower among participants in the most active tertile of MVPA compared to the least active tertile (adjusted odds ratio = 0.87, 95% CI = 0.80, 0.95). Similar decreases were observed across NHL subtypes. In summary, in this pooled analysis of case-control studies, physical activity was associated with a modest risk reduction for each NHL subtype examined and with overall NHL.

Obesity and Risk for Lymphoma: Possible Role of Leptin

Obesity, which is considered a pandemic due to its high prevalence, is a risk factor for many types of cancers, including lymphoma, through a variety of mechanisms by promoting an inflammatory state. Specifically, over the last few decades, obesity has been suggested not only to increase the risk of lymphoma but also to be associated with poor clinical outcomes and worse responses to different treatments for those diseases. Within the extensive range of proinflammatory mediators that adipose tissue releases, leptin has been demonstrated to be a key adipokine due to its pleotropic effects in many physiological systems and diseases. In this sense, different studies have analyzed leptin levels and leptin/leptin receptor expressions as a probable bridge between obesity and lymphomas. Since both obesity and lymphomas are prevalent pathophysiological conditions worldwide and their incidences have increased over the last few years, here we review the possible role of leptin as a promising proinflammatory mediator promoting lymphomas.

Second malignant neoplasms in lymphomas, secondary lymphomas and lymphomas in metabolic disorders/diseases

With inconsistent findings, evidence has been obtained in recent years that metabolic disorders are closely associated with the development of lymphomas. Studies and multiple analyses have been published also indicating that some solid tumor survivors develop a secondary lymphoma, whereas some lymphoma survivors subsequently develop a second malignant neoplasm (SMN), particularly solid tumors. An interaction between the multiple etiologic factors such as genetic factors and late effects of cancer therapy may play an important role contributing to the carcinogenesis in patients with metabolic diseases or with a primary cancer. In this review, we summarize the current knowledge of the multiple etiologic factors for lymphomagenesis, focusing on the SMN in lymphoma, secondary lymphomas in primary cancers, and the lymphomas associated to metabolic disorders/diseases, which have been received less attention previously. Further, we also review the data of coexistence of lymphomas and hepatocellular carcinoma (HCC) in patients with infection of hepatitis C virus and hepatitis B virus.

Associations between early-life growth pattern and body size and follicular lymphoma risk and survival: a family-based case-control study

BACKGROUND

The influence of early-life growth pattern and body size on follicular lymphoma (FL) risk and survival is unclear. In this study, we aimed to investigate the association between gestational age, growth during childhood, body size, changes in body shape over time, and FL risk and survival.

METHODS

We conducted a population-based family case-control study and included 706 cases and 490 controls. We ascertained gestational age, growth during childhood, body size and body shape using questionnaires and followed-up cases (median=83 months) using record linkage with national death records. We used a group-based trajectory modeling approach to identify body shape trajectories from ages 5-70. We examined associations with FL risk using unconditional logistic regression and used Cox regression to assess the association between body mass index (BMI) and all-cause and FL-specific mortality among cases.

RESULTS

We found no association between gestational age, childhood height and FL risk. We observed a modest increase in FL risk with being obese 5 years prior to enrolment (OR=1.43, 95 %CI=0.99-2.06; BMI ≥30 kg/m²) and per 5-kg/m² increase in BMI 5 years prior to enrolment (OR=1.14, 95 %CI=0.99-1.31). The excess risk for obesity 5 years prior to enrolment was higher for ever-smokers (OR=2.00, 95 %CI=1.08-3.69) than never-smokers (OR=1.14, 95 %CI=0.71-1.84). We found no association between FL risk and BMI at enrolment, BMI for heaviest lifetime weight, the highest categories of adult weight or height, trouser size, body shape at different ages or body shape trajectory. We also observed no association between all-cause or FL-specific mortality and excess adiposity at or prior to enrolment.

CONCLUSION

We observed a weak association between elevated BMI and FL risk, and no association with all-cause or FL-specific mortality, consistent with previous studies. Future studies incorporating biomarkers are needed to elucidate possible mechanisms underlying the role of body composition in FL etiology.

Determinants of non-Hodgkin's lymphoma at Felegehiwot specialized hospital, North West Ethiopia: A case-control study

BACKGROUND

The global burden of cancer continues to increase largely because of the aging and growth of the world population alongside an increasing adoption of cancer-causing behaviors. Hence, the purpose of this study was to identify determinants of Non-Hodgkin lymphoma cancer among individuals who diagnosed at the Felegehiwot specialized hospital, North West Ethiopia, 2019.

METHODS

An institution-based unmatched case-control study was conducted at the Felegehiwot Specialized hospital from December 2018 up to June 2019. The sample size calculated using the two-population proportion formula. The final sample size was 486, (162 cases and 324 controls). The simple random sampling method was employed to catch up with the estimated samples. The collected data entered into the Epi-data version 3.1 software and analyzed using SPSS version 21 software. Descriptive statistics computed. Simple logistic analysis was run (at 95% CI and p-value < 0.05) to identify the determinants of non-Hodgkin's lymphoma.

RESULT

A total of 486 patients participated. Nearly one-third of the cases and controls were in the age group of 46-60 years. About 90% of cases and 91% of controls were orthodox Christian. Monthly income of ≤28 dollars (AOR = 2. 73, 95%CI: 1. 8, 4.2), male sex (AOR = 1. 8, 95%CI: 1.2, 2.8), ever had chemical exposure, (AOR = 11. 9, 95%CI: 7.6, 18.8), no regular physical exercise (AOR = 15. 5, 95%CI: 5.7, 42.3), and having hypertension [AOR = 0. 03; 95%CI:0.005, 0.2), lung disease (AOR = 0. 2; 95%CI: 0.06, 0.7), and chronic kidney and cardiac diseases (AOR = 0. 06; 95%CI: 0.01, 0.2) were the determinants of non-Hodgkin's lymphoma.

CONCLUSIONS

The findings in this study suggest that having a low monthly income, being male sex, ever had chemical exposure, not engaged in regular physical exercise, and being diabetic were the determinants of non-Hodgkin's lymphoma.

The relationship between physical activity and lymphoma: a systematic review and meta analysis

Background

The literature suggests an increased risk between anthropometrics including higher body mass index and lymphoma incidence; however, the association with physical activity remains unclear. A systematic review/meta-analysis was therefore performed to examine this association with physical activity (total, recreational or occupational).

Methods

PubMed, Web of Science and Embase were reviewed from inception to October 2019 identifying relevant observational studies. Non-Hodgkin lymphoma (NHL) including subtypes diffuse large B cell lymphoma, follicular lymphoma and chronic lymphocytic leukemia/small lymphocytic lymphoma, and Hodgkin lymphoma (HL) were analyzed. Included studies reported activity, lymphoma cases, effect size and variability measures, and were restricted to human subjects of any age. Data was pooled generating summary relative risk (RR) estimates with 95% confidence intervals (CI) using random-effects models with primary outcome of histologically confirmed incident lymphoma.

Results

One thousand four hundred studies were initially identified with 18 studies (nine cohort, nine case-control) included in final analysis. Comparing highest vs. lowest activity categories was protective for all lymphoma (RR 0.89, 95%CI 0.81–0.98). Sensitivity analysis demonstrated effect persistence within case-control studies (RR 0.82, 95% CI 0.71–0.96), but not cohort studies (RR 0.95, 95%CI 0.84–1.07). Borderline protective effect was seen for NHL (RR 0.92, 95%CI 0.84–1.00), but not HL (RR 0.72, 95%CI 0.50–1.04). Analysis by NHL subtype or gender showed no effect. Dose response analysis demonstrated a protective effect (p = 0.034) with a 1% risk reduction per 3 MET hours/week (RR 0.99, 95%CI 0.98–1.00).

Conclusions

Physical activity may have a protective effect against lymphoma development; further studies are required to generate recommendations regarding health policy.

Trial registration

This study was registered prospectively at PROSPERO: CRD42020156242.

Distinctive incidence patterns of follicular lymphoma in Taiwan: Implications of ethnic differences

BACKGROUND

Follicular lymphoma (FL) is less prevalent in Asians, but detailed epidemiological analyses were not available. This study aimed to characterize the epidemiologic features of FL in Taiwan to explore the factors relevant to disease development and prognosis.

METHODS

We obtained epidemiological data for Taiwanese citizens during 1990-2012 from Taiwan's National Cancer Registry Database, and the corresponding data for US Caucasians from the Surveillance, Epidemiology, and End Results Program. Changes in incidence rates were evaluated with age-period-cohort (APC) analyses. Patient outcomes were compared with 5-year relative survival rates (RS) estimates.

RESULTS

Incidence rates of FL in Taiwan increased continuously during the study period (0.34 to 0.91 per 100 000 person-year from 1993-1997 to 2008-2012 in men, and from 0.29 [1993-1997] to 0.81 [2008-2012] in women), while rates in the US remained stable in both sexes, ranging between 3.73 and 3.96 in men and between 3.24 and 3.55 in women. Estimates of average annual percentage changes in incidence were significantly positive in Taiwan, but not in US Caucasians. Notably, the APC analysis identified a strong birth-cohort effect in Taiwan, corresponding to environmental alterations present during the study period. The estimated 5-year RS rates in both populations showed steady improvement, but the RS in Taiwanese patients was consistently 10% lower than in US Caucasians.

CONCLUSION

A distinct increasing trend of incidence with a strong birth-cohort effect was identified in Taiwan, providing evidence of the association between environmental factors and disease development.

Dietary fat intake and risk of non-Hodgkin lymphoma in 2 large prospective cohorts

Background: Dietary fat intake may contribute to non-Hodgkin lymphoma (NHL) pathogenesis by influencing carcinogen exposure or through immune modulation.Objective: We aimed to evaluate NHL risk associated with total and specific dietary fat intake.Design: We evaluated associations within the Nurses' Health Study (NHS) (n = 88,598) and the Health Professionals Follow-Up Study (HPFS) (n = 47,531) using repeated validated dietary assessments. We confirmed 1802 incident NHL diagnoses through 2010. Using multivariable Cox proportional hazards models, we estimated hazard ratios (HRs) for all NHL and common subtypes associated with a 1-SD increase in cumulative mean intakes of total, animal, saturated, trans, and vegetable fats and marine fatty acids. We pooled sex-specific HRs using random-effects meta-analysis.Results: Over 24-30 y of follow-up, neither total nor specific dietary fats were significantly associated with NHL risk overall. Higher total, animal, and saturated fat intakes were positively associated with the risk of the chronic lymphocytic leukemia/small lymphocytic lymphoma subtype among women only (253 cases; P-trend ≤ 0.05), driven by strong associations during 1980-1994. From baseline through 1994, among women and men combined, total fat intake was borderline-significantly positively associated with NHL overall (pooled HR per SD: 1.13; 95% CI: 0.99, 1.29) and was significantly associated with diffuse large B cell lymphoma (pooled HR per SD: 1.47; 95% CI: 1.06, 2.05), with similar trends for animal and saturated fat intake. For women only, trans fat was significantly positively associated with all NHL. In contrast, during 1994-2010, there was little evidence for associations of dietary fat intake with NHL overall or by subtype.Conclusion: Previous observations of an increased risk of NHL associated with intakes of total, animal, saturated, and trans fat with 14 y of follow-up did not persist with longer follow-up.

Lifetime physical activity and the risk of non-Hodgkin lymphoma

Research regarding the association between physical activity and the risk of non-Hodgkin lymphoma (NHL) is limited and inconsistent, and few studies have investigated whether the intensity and timing of physical activity influence the association. A case-control study of NHL was conducted in British Columbia, Canada, in 2000 to 2004. Data were collected on various NHL risk factors, including moderate-intensity and vigorous-intensity physical activity performed over the lifetime. Logistic regression was used to estimate the association between physical activity and the risk of NHL. This analysis included 818 controls and 749 cases. Lifetime vigorous-intensity physical activity was inversely associated with NHL risk. Participants in the second, third, and fourth quartiles of lifetime vigorous-intensity physical activity had an approximately 25% to 30% lower risk of NHL than those in the lowest quartile [adjusted odds ratios, 0.69 (95% confidence interval [CI], 0.52-0.93); 0.68 (95% CI, 0.50-0.92); and 0.75 (95% CI, 0.55-1.01), respectively]. No consistent associations were observed for total or moderate-intensity physical activity. There were no apparent age periods in which physical activity appeared to confer a greater risk reduction. In this study, we found that lifetime vigorous-intensity physical activity was associated with a significantly reduced risk of NHL. Given this finding, more research on physical activity intensity and timing in relation to NHL risk is warranted.

Medical history, lifestyle, family history, and occupational risk factors for mycosis fungoides and Sézary syndrome: the InterLymph Non-Hodgkin Lymphoma Subtypes Project

BACKGROUND

Mycosis fungoides and Sézary syndrome (MF/SS) are rare cutaneous T-cell lymphomas. Their etiology is poorly understood.

METHODS

A pooled analysis of 324 MF/SS cases and 17217 controls from 14 case-control studies from Europe, North America, and Australia, as part of the International Lymphoma Epidemiology Consortium (InterLymph) Non-Hodgkin Lymphoma (NHL) Subtypes Project, was carried out to investigate associations with lifestyle, medical history, family history, and occupational risk factors. Multivariate logistic regression models were used to calculate odds ratios (OR) and 95% confidence intervals (CI).

RESULTS

We found an increased risk of MF/SS associated with body mass index equal to or larger than 30 kg/m(2) (OR = 1.57, 95% CI = 1.03 to 2.40), cigarette smoking for 40 years or more (OR = 1.55, 95% CI = 1.04 to 2.31), eczema (OR = 2.38, 95% CI = 1.73 to 3.29), family history of multiple myeloma (OR = 8.49, 95% CI = 3.31 to 21.80), and occupation as crop and vegetable farmers (OR = 2.37, 95% CI = 1.14 to 4.92), painters (OR = 3.71, 95% CI = 1.94 to 7.07), woodworkers (OR = 2.20, 95% CI = 1.18 to 4.08), and general carpenters (OR = 4.07, 95% CI = 1.54 to 10.75). We also found a reduced risk of MF/SS associated with moderate leisure time physical activity (OR = 0.46, 95% CI = 0.22 to 0.97).

CONCLUSIONS

Our study provided the first detailed analysis of risk factors for MF/SS and further investigation is needed to confirm these findings in prospective data and in other populations.

Incidence of haematological malignancies by ethnic group in England, 2001-7

The aetiology of most haematological malignancies is largely unknown. Studies of migrant populations can provide insights into the relative importance of genetic and environmental risk factors for these diseases. This study compares incidence rates in British Indians, Pakistanis, Bangladeshis, Black Africans, Black Caribbeans, Chinese and Whites in England from 2001 to 2007. We analysed 134,302 haematological cancer registrations with ethnicity obtained by linkage to the Hospital Episodes Statistics database. Mid-year population estimates from 2001 to 2007 were used. Incidence rate ratios adjusted for age, sex and income were calculated, comparing the six ethnic groups to Whites and to each other. Whites had the highest rates for most subtypes. However, Blacks experienced more than double the incidence of plasma cell and mature T-cell neoplasms compared to other ethnic groups. There were also significant differences in incidence between Indians, Pakistanis and Bangladeshis for Hodgkin lymphoma and mature B-cell neoplasms and between Black African and Black Caribbeans for mature B-cell and other lymphoid neoplasms (all P < 0.001). Our results show that the risk of haematological cancers varies greatly by ethnic group, including within those groups that have traditionally been grouped together (South Asians and Blacks) with many of these differences not explicable by known risk factors.

A prospective analysis of body size during childhood, adolescence, and adulthood and risk of non-Hodgkin lymphoma

The etiology of non-Hodgkin lymphoma (NHL) is poorly understood. Obesity is associated with inflammation, a cytokine milieu conducive to lymphocyte proliferation, and has been associated with NHL risk in some epidemiologic studies. To prospectively examine NHL risk in relation to adult and earlier life obesity, we documented 635 incident NHL diagnoses among 46,390 men in the Health Professionals Follow-up Study and 1,254 diagnoses among 116,794 women in the Nurses' Health Study over 22 to 32 years of follow-up. Using multivariable Cox proportional hazards models, we estimated cohort-specific incidence rate ratios (RR) and 95% confidence intervals (CI) for risk of NHL and major histologic subtypes associated with cumulative average middle and young adult (ages, 18-21 years) body mass index (BMI) and adolescent and childhood somatotype. NHL risk was modestly increased in men (but not women) with a cumulative average middle adult BMI ≥ 30 kg/m(2) (vs. 15-22.9 kg/m(2); RR, 1.28; 95% CI, 0.92-1.77; Ptrend = 0.05). In meta-analyses across cohorts, higher young adult BMI was associated with increased risk of all NHL (pooled RR per 5 kg/m(2), 1.19; 95% CI, 1.05-1.37), diffuse large B-cell lymphoma (DLBCL), and follicular lymphoma (all Ptrend ≤ 0.02). Adolescent somatotype was also positively associated with all NHL, DLBCL, and follicular lymphoma in pooled analyses (all Ptrend ≤ 0.03), whereas childhood somatotype was positively associated with NHL overall among women only (Ptrend < 0.01). These findings in two large prospective cohorts provide novel evidence that larger body size in childhood, adolescence, and young adulthood predicts increased risk of NHL, and particularly of DLBCL and follicular lymphoma.

Body mass index, weight change, and survival in non-Hodgkin lymphoma patients in Connecticut women

Evidence is emerging that obesiy and weight gain may affect the prognosis of several types of cancer. We investigated the impact of body mass index (BMI) as well as pre-and postdiagnosis weight changes on non-Hodgkin lymphoma (NHL) prognosis. A cohort of 573 female incident NHL cases diagnosed during 1996-2000 in Connecticut was followed for a median of 7.8 yr. Self-reported height and weight at 3 time points before and after diagnosis were collected. Hazard ratios (HR) and 95% confidence intervals (CI) were estimated using proportional hazard models adjusting for factors believed to be associated with overall survival of NHL. Underweight (BMI < 18.5; HR = 2.84; 95% CI = 1.12-7.15) before diagnosis was associated with poorer survival compared to being normal weight (18.5 ≤ BMI < 25). Prediagnosis weight loss (HR = 1.42; 95% CI = 1.02-1.97) and posttreatment weight loss (HR = 1.98; 95% CI = 1.14-3.45) and weight gain (HR = 1.85; 95% CI = 1.04-3.32) were associated with poorer survival. NHL patients who were underweight, lost weight prediagnosis, or change weight after treatment were found to have a poorer survival.

Polymorphisms in DNA repair pathway genes, body mass index, and risk of non-Hodgkin lymphoma

We conducted a population-based case-control study in Connecticut women to test the hypothesis that genetic variations in DNA repair pathway genes may modify the relationship between body mass index (BMI) and risk of non-Hodgkin lymphoma (NHL). Compared to those with BMI <25, women with BMI ≥25 had significantly increased risk of NHL among women who carried BRCA1 (rs799917) CT/TT, ERCC2 (rs13181) AA, XRCC1 (rs1799782) CC, and WRN (rs1801195) GG genotypes, but no increase in NHL risk among women who carried BRCA1 CC, ERCC2 AC/CC, XRCC1 CT/TT, and WRN GT/TT genotypes. A significant interaction with BMI was only observed for WRN (rs1801195; P = 0.004) for T-cell lymphoma and ERCC2 (rs13181; P = 0.002) for diffuse large B-cell lymphoma. The results suggest that common genetic variation in DNA repair pathway genes may modify the association between BMI and NHL risk.

Body size in relation to incidence of subtypes of haematological malignancy in the prospective Million Women Study

Background:

Greater adiposity and height have been associated with increased risk of haematological malignancies. Associations for disease subtypes are uncertain.

Methods:

A cohort of 1.3 million middle-aged UK women was recruited in 1996–2001 and followed for 10 years on average. Potential risk factors were assessed by questionnaire. Death, emigration, and incident cancer were ascertained by linkage to national registers. Adjusted relative risks were estimated by Cox regression.

Results:

During follow-up, 9162 participants were diagnosed with lymphatic or haematopoietic cancers. Each 10 kg m⁻² increase in body mass index was associated with relative risk of 1.20 (95% confidence interval: 1.13–1.28) for lymphoid and 1.37 (1.22–1.53) for myeloid malignancy (P=0.06 for heterogeneity); similarly, Hodgkin lymphoma 1.64 (1.21–2.21), diffuse large B-cell lymphoma 1.36 (1.17–1.58), plasma cell neoplasms 1.21 (1.06–1.39), acute myeloid leukaemia 1.47 (1.19–1.81), and myeloproliferative/myelodysplastic syndromes 1.32 (1.15–1.52). Each 10 cm increase in height was associated with relative risk of 1.21 (1.16–1.27) for lymphoid and 1.11 (1.02–1.21) for myeloid malignancy (P=0.07 for heterogeneity); similarly, mature T-cell malignancies 1.36 (1.03–1.79), diffuse large B-cell lymphoma 1.28 (1.14–1.43), follicular lymphoma 1.28 (1.13–1.44), plasma cell neoplasms 1.12 (1.01–1.24), chronic lymphocytic leukaemia/small lymphocytic lymphoma 1.23 (1.08–1.40), and acute myeloid leukaemia 1.22 (1.04–1.42). There was no significant heterogeneity between subtypes.

Conclusion:

In middle-aged women, greater body mass index and height were associated with modestly increased risks of many subtypes of haematological malignancy.

Regular recreational physical activity and risk of hematologic malignancies: results from the prospective VITamins And lifestyle (VITAL) study

BACKGROUND

Conflicting evidence exists on the relationship between physical activity (PA) and incident hematologic malignancies. Herein, we used a large cohort study to examine this association.

PATIENTS AND METHODS

Sixty-five thousand three hundred twenty-two volunteers aged 50-76 years were recruited from 2000 to 2002. Incident hematologic malignancies (n = 666) were identified through 2009 by linkage to the Surveillance, Epidemiology, and End Results cancer registry. Hazard ratios (HRs) for hematologic malignancies associated with PA averaged over 10 years before baseline were estimated with Cox proportional hazards models, adjusting for factors associated with hematologic cancers or PA.

RESULTS

There was a decreased risk of hematologic malignancies associated with PA (HR = 0.66 [95% confidence interval, 95% CI 0.51-0.86] for the highest tertile of all PA, P-trend = 0.005, and HR = 0.60 [95% CI 0.44-0.82] for the highest tertile of moderate/high-intensity PA, P-trend = 0.002). These associations were strongest for myeloid neoplasms (HR = 0.48 [95% CI 0.29-0.79] for the highest tertile of all PA, P-trend = 0.013, and HR = 0.40 [95% CI 0.21-0.77] for the highest tertile of moderate/high-intensity PA, P-trend = 0.016). There were also significant associations between PA and chronic lymphocytic leukemia/small lymphocytic lymphoma or other mature B-cell lymphomas except plasma cell disorders.

CONCLUSIONS

Our study offers the strongest epidemiological evidence, to date, to suggest an association between regular PA and dose-dependent risk reduction for most hematologic malignancies, particularly myeloid neoplasms.

Small lymphocytic lymphoma and chronic lymphocytic leukemia: are they the same disease?

Chronic lymphocytic leukemia (CLL) is the most common leukemia in the Western world, characterized by peripheral blood B-cell lymphocytosis as well as lymphadenopathy, organomegaly, cytopenias, and systemic symptoms. Chronic lymphocytic leukemia cells have a distinctive immunophenotype, and the disease has a characteristic pattern of histological infiltration in the lymph node and bone marrow. The clinical course of CLL is heterogeneous, with some patients presenting with very indolent disease and other patients having a more aggressive malignancy. It is known that genetic abnormalities underlie this difference in clinical presentation. Some patients may present solely with lymphadenopathy, organomegaly, and presence of infiltrating monoclonal B cells with the same immunophenotype as CLL cells, but lacking peripheral blood lymphocytosis. This disease is called small lymphocytic lymphoma (SLL) and has been considered for almost 2 decades to be the tissue equivalent of CLL. Both CLL and SLL are currently considered different manifestations of the same entity by the fourth edition of the World Health Organization Classification of Tumours of Haematopoietic and Lymphoid Tissues. It is suspected that differential expression of chemokine receptors (e.g., reduced expression of R1 and CCR3 in SLL cells), integrins (e.g., CLL cells have lower expression of integrin αLβ2), and genetic abnormalities (a higher incidence of trisomy 12 and lower incidence of del(13q) is found in SLL) may explain some of the clinical differences between these 2 disorders. However, there is still a lack of knowledge on the precise biological basis underlying the different clinical presentations of CLL and SLL. It is expected that future studies will shed light on the pathophysiology of both disorders.

Body mass index, height and risk of lymphoid neoplasms in a large United States cohort

Results from epidemiologic studies examining associations between body size and risk of non-Hodgkin lymphoma (NHL) are inconsistent, and etiology may vary by histologic subtype of disease. Using Cox proportional hazards regression, multivariable relative risks (RRs) and 95% confidence intervals (CIs) were computed for associations of body mass index (BMI) and height with NHL in the prospective American Cancer Society Cancer Prevention Study-II Nutrition Cohort. From 1992 to 2007, 2074 incident cases of NHL were identified among 152 423 men and women. Obese individuals (BMI ≥ 30 kg/m(2)) had 23% higher incidence of NHL (95% CI 1.08-1.40) compared to those with normal weight (BMI 18.5-< 25 kg/m(2)). Height was positively associated with NHL (RR = 1.25, 95% CI 1.10-1.43, sex-specific quintile 5 vs. 1). BMI associations were strongest for diffuse large B-cell lymphoma. Height was most strongly associated with chronic lymphocytic leukemia/small lymphocytic lymphoma and to a lesser extent with multiple myeloma. These findings provide further evidence that body size may play a role in the etiology of NHL, which is of public health importance given the rapid rise in obesity worldwide.

The association between early life and adult body mass index and physical activity with risk of non-Hodgkin lymphoma: impact of gender

PURPOSE

To evaluate the association of body mass index (BMI) and physical activity (PA) during adulthood and at the age of 18 years with risk of non-Hodgkin lymphoma (NHL).

METHODS

We enrolled 950 newly diagnosed NHL patients and 1146 frequency-matched clinic-based controls. Height, weight, and PA (recent adult and at the age of 18 years) were self-reported. Odds ratios (ORs), 95% confidence intervals, and tests for trend were estimated using unconditional logistic regression adjusted for age, gender, and residence.

RESULTS

BMI at the age of 18 years was associated with an increased NHL risk (OR, 1.38 for highest vs. lowest quartile; p-trend = .0012), which on stratified analysis was specific to females (OR, 1.90; p-trend = .00025). There was no association of adult BMI with NHL risk. Higher PA in adulthood (OR, 1.03; p-trend = .85) or at the age of 18 years (OR, 0.88; 95% confidence interval, 0.72-1.07) was not associated with risk, but there was an inverse association for adult PA that was specific to females (OR, 0.71; p-trend = .039). Only BMI at the age of 18 years remained significantly associated with NHL risk when modeled together with PA in adulthood or at the age of 18 years. There was little evidence for heterogeneity in these results for the common NHL subtypes.

CONCLUSIONS

Early adult BMI may be of greatest relevance to NHL risk, particularly in females.

Exploring risk factors for follicular lymphoma

Follicular lymphoma (FL) is an indolent malignancy of germinal center B cells with varied incidence across racial groups and geographic regions. Improvements in the classification of non-Hodgkin lymphoma subtypes provide an opportunity to explore associations between environmental exposures and FL incidence. Our paper found that aspects of Western lifestyle including sedentary lifestyle, obesity, and diets high in meat and milk are associated with an increased risk of FL. Diets rich in fruits and vegetables, polyunsaturated fatty acids, vitamin D, and certain antioxidants are inversely associated with FL risk. A medical history of Sjogren's syndrome, influenza vaccination, and heart disease may be associated with FL incidence. Associations between FL and exposure to pesticides, industrial solvents, hair dyes, and alcohol/tobacco were inconsistent. Genetic risk factors include variants at the 6p21.32 region of the MHC II locus, polymorphisms of the DNA repair gene XRCC3, and UV exposure in individuals with certain polymorphisms of the vitamin D receptor. Increasing our understanding of risk factors for FL must involve integrating epidemiological studies of genetics and exposures to allow for the examination of risk factors and interactions between genes and environment.

Intake of vitamins D and A and calcium and risk of non-Hodgkin lymphoma: San Francisco Bay Area population-based case-control study

Several nutrients identified as potentially cancer protective have been inconsistently associated with non-Hodgkin lymphoma (NHL) risk. Dietary history data, including use of vitamin supplements, were collected using a semiquantitative food frequency questionnaire administered during in-person interviews with 4,133 participants (2,052 cases, 2,081 controls) in a San Francisco Bay Area population-based case-control study. Data were used to determine the association of intake levels of vitamins D and A and calcium with risk of NHL and NHL subtypes. Odds ratios (OR) and 95% confidence intervals (CI) were computed as estimates of relative risk using adjusted unconditional logistic regression. Increasing vitamin D intake from food and supplements was positively associated with NHL risk in men (5th quintile: OR = 1.6, 95% CI = 1.0-2.4, P(trend) = 0.07) and with diffuse large B-cell lymphoma (DLBCL) in women and men (5th quintile: OR = 1.6, 95% CI = 1.0-2.5, P(trend) = 0.02); that was largely due to the effect in men (P(trend) = 0.03). These results do not support a strong role for vitamin D intake with NHL risk, with the exception of a potential association for DLBCL risk in men. Our results should be interpreted conservatively until further investigation in larger pooled studies can be conducted to better assess the role of vitamin D intake in lymphomagenesis.

Anthropometric factors, physical activity, and risk of non-Hodgkin's lymphoma in the Women's Health Initiative

BACKGROUND

Incidence rates of non-Hodgkin's lymphoma (NHL) increased substantially in the United States and worldwide during the latter part of the 20th century, but little is known about its etiology. Obesity is associated with impaired immune function through which it may influence the risk of NHL; other factors reflecting energy homeostasis (height, abdominal adiposity, and physical activity) may also be involved.

METHODS

We examined the association of anthropometric factors and physical activity with risk of NHL and its major subtypes in a large cohort of women aged 50-79 years old who were enrolled at 40 clinical centers in the United States between 1993 and 1998. Over a mean follow-up period of 11 years, 1123 cases of NHL were identified among 158,975 women. Cox proportional hazards models were used to estimate hazard ratios (HR) and 95% confidence intervals (CI).

RESULTS

Height at baseline was positively associated with risk of all NHL and with that of diffuse large B-cell lymphoma (HRs(q4vs.q1) 1.19, 95% CI 1.00-1.43 and 1.43, 95% CI 1.01-2.03, respectively). Measures of obesity and abdominal adiposity at baseline were not associated with risk. Hazard ratios for NHL were increased for women in the highest quartile of weight and body mass index at age 18 (HRs(q4vs.q1) 1.29, 95% CI 1.01-1.65 and 1.27, 95% CI 1.01-1.59, respectively). Some measures of recreational physical activity were modestly associated with increased risk of NHL overall, but there were no clear associations with specific subtypes.

CONCLUSION

Our findings regarding anthropometric measures are consistent with those of several previous reports, suggesting that early life influences on growth and immune function may influence the risk of NHL later in life.

Cytokine polymorphisms in Th1/Th2 pathway genes, body mass index, and risk of non-Hodgkin lymphoma

We conducted a population-based, case-control study in Connecticut women to test the hypothesis that genetic variations in Th1 and Th2 cytokine genes modify the relationship between body mass index (BMI) and risk of non-Hodgkin lymphoma (NHL). Compared with those with BMI less than 25 kg/m(2), women with BMI more than or equal to 25 kg/m(2) had 50% to 90% increased risk of NHL among women who carried IFNGR2 (rs9808753) AA, IL5 (rs2069812) CT/TT, IL7R (rs1494555) AA, and TNF (rs1799724) CC genotypes, but no increased risk among women with IFNGR2 AG/GG, IL5 CC, IL7R AG/GG, and TNF CT/TT genotypes. A significant interaction with BMI was only observed for IFNGR2 (rs9808753 P(forinteraction) = .034) and IL7R (rs1494555 P(forinteraction) = .016) for NHL overall; IL7R (rs1494555 P(forinteraction) = .016) and TNF (1799724 P(forinteraction) = .031) for B-cell lymphoma; and IL5 (rs2069812 P(forinteraction) = .034) for T-cell lymphoma. After stratification by common B-cell lymphoma subtypes, a significant interaction was observed for IFNGR2 (rs9808753 P(forinteraction) = .006), IL13 (rs20541 P(forinteraction) = .019), and IL7R (rs1494555 P(forinteraction) = .012) for marginal zone B-cell lymphoma; IL7R (rs1494555 P(forinteraction) = .017) for small lymphocytic lymphoma/chronic lymphocytic leukemia; and IL12A (rs568408 P(forinteraction) = .013) and TNF (1799724 P(forinteraction) = .04) for follicular lymphoma. The results suggest that common genetic variation in Th1/Th2 pathway genes may modify the association between BMI and NHL risk.

Obesity and the risk for a hematological malignancy: leukemia, lymphoma, or myeloma

Studies on obesity and the risk for hematological malignancies are reviewed. The paper includes a discussion of the metabolic effects of obesity and their possible role in linking increased body fat to neoplasia.

The aggregate of epidemiological studies indicates a significantly elevated risk for cancer in people with a high body mass index (BMI); a “dose–response” effect exists with increasing risk as BMI increases from the normal to overweight to obese categories. Successful sustained weight loss decreases future risk. The relationship of being overweight to the risk for leukemia in the aggregate has been supported in several large cohort studies and two meta-analyses of cohort and case–control studies. One meta-analysis found an elevated risk for each of the four major subtypes of leukemia. A significant association between the risk for non-Hodgkin's lymphoma and elevated BMI was supported by a meta-analysis of 13 cohort and nine case–control studies. The risk for diffuse large B-cell lymphoma may be especially significant. A high BMI increases the risk for myeloma, as judged by a meta-analysis of 11 cohort and four case–control studies. The biological relationship of obesity to the risk for cancer (biological plausibility) is unresolved. The two major causal final pathways could be “inductive” or “selective.” The metabolic, endocrinologic, immunologic, and inflammatory-like changes resulting from obesity may increase the cell mutation rate, dysregulate gene function, disturb DNA repair, or induce epigenetic changes, favoring the induction of neoplastic transformation (inductive). Alternatively, obesity may create an environment in which pre-existing clones that are dormant are permitted (selected) to emerge.

A hospital-based case-control study of non-Hodgkin lymphoid neoplasms in Shanghai: analysis of personal characteristics, lifestyle, and environmental risk factors by subtypes of the WHO classification

OBJECTIVES

To investigate potential risk factors (personal characteristics, lifestyle, and environmental factors) of non-Hodgkin lymphoid neoplasms (NHLN), including lymphomas and lymphocytic leukemia, according to the World Health Organization classification.

MATERIALS AND METHODS

The investigation was a hospital-based case-control study consisting of 649 confirmed NHLN cases and 1298 individually gender-age-matched patient controls at 25 hospitals in Shanghai. A 17-page questionnaire was used to obtain information on demographics, medical history, family history, lifestyle risk factors, employment history, residential history, and occupational and non-occupational exposures. Risk estimates were calculated using conditional logistic regression models.

RESULTS

Potential risk factors of NHLN (all subtypes combined) or individual subtypes included low-level education, home or workplace renovation, living on a farm, planting crops, and raising livestock or animals. Some risk factors applied to all or most subtypes (such as lowlevel education, living on a farm, and raising livestock or animals), whereas others did not (such as the use of traditional Chinese medicines, which was associated with a reduced risk). Blood transfusions, hair dyes, or living near high-voltage power lines were not associated with an increased risk.

CONCLUSIONS

The study identified a number of risk factors for NHLN overall and specific subtypes. Some risk factors were subtype-specific. The difference in risk by subtype underscores the etiologic commonality and heterogeneity of NHLN subtypes.

Temporal and demographic patterns of non-Hodgkin's lymphoma incidence in Pennsylvania

Our study analyzed temporal and demographic patterns of non-Hodgkin's lymphoma (NHL) incidence in Pennsylvania and compared Pennsylvania time trends with national trends. Joinpoint and age-period-cohort analyses summarized sex- and race-specific NHL incidence time trends between 1985 and 2004. Ecologic analysis identified demographic factors associated with age-adjusted county-specific NHL incidence. NHL incidence in Pennsylvania increased annually: 1.6% and 2.5% in white and black men and 1.6% and 3.2% in white and black women. National trends were similar, except for smaller increases in white men. Diffuse lymphoma appeared to be the major contributor to the increases. NHL incidence was higher in Pennsylvania counties with greater percentages of urban residents. NHL incidence patterns in Pennsylvania were parallel to those seen nationally, with the highest rates occurring in white men and in persons residing in urban areas.

Physical activity and hematologic cancer prevention

This chapter presents the epidemiologic evidence on the association between physical activity and hematologic cancers and related hypothesized biologic mechanisms. Some preliminary indications of a protective role for physical activity for non-Hodgkin's lymphoma, leukemia, multiple myeloma, and Hodgkin's lymphoma exist, but the level of epidemiologic evidence is still insufficient to make any definitive conclusions regarding the nature of these associations. Several plausible biologic mechanisms underlying the possible associations between physical activity and hematologic cancers have been proposed, including enhancement of immune function, reduction in obesity, improvement of antioxidant defense systems, impact on metabolic hormones, and anti-inflammatory effects. Future studies should improve the estimation of physical activity by using more reliable, valid, and comprehensive measurement tools, assessing all components of physical activity (type, intensity, and time period), and conducting intervention studies to evaluate the effect of physical activity on various biomarkers of cancer in order to provide further insight into plausible biologic mechanisms underlying the possible association between physical activity and hematologic cancers.

Body size, recreational physical activity, and B-cell non-Hodgkin lymphoma risk among women in the California teachers study

Nutritional status and physical activity are known to alter immune function, which may be relevant to lymphomagenesis. The authors examined body size measurements and recreational physical activity in relation to risk of B-cell non-Hodgkin lymphoma (NHL) in the prospective California Teachers Study. Between 1995 and 2007, 574 women were diagnosed with incident B-cell NHL among 121,216 eligible women aged 22-84 years at cohort entry. Multivariable-adjusted relative risks and 95% confidence intervals were estimated by fitting Cox proportional hazards models for all B-cell NHL combined and for the 3 most common subtypes: diffuse large B-cell lymphoma, follicular lymphoma, and B-cell chronic lymphocytic leukemia/small lymphocytic lymphoma. Height was positively associated with risk of all B-cell NHLs (for >1.70 vs. 1.61-1.65 m, relative risk = 1.50, 95% confidence interval: 1.16, 1.96) and chronic lymphocytic leukemia/small lymphocytic lymphoma (relative risk = 1.93, 95% confidence interval: 1.09, 3.41). Weight and body mass index at age 18 years were positive predictors of B-cell NHL risk overall. These findings indicate that greater height, which may reflect genetics, early life immune function, infectious exposures, nutrition, or growth hormone levels, may play a role in NHL etiology. Adiposity at age 18 years may be more relevant to NHL etiology than that in later life.

Body mass index, height, and risk of lymphatic malignancies: a prospective cohort study

The association among body mass index (BMI), height, and the risk of lymphatic malignancies was investigated in the Netherlands Cohort Study. The participants (n = 120,852), Dutch men and women aged 55-69 years, completed a self-administered questionnaire at baseline in 1986. After 13.3 years of follow-up, data on 1,042 lymphatic malignancy cases (including diffuse large-cell lymphoma, chronic lymphocytic leukemia, multiple myeloma, and other subtypes) and 4,588 subcohort members were available. Incidence rate ratios were estimated by using Cox regression models. BMI at baseline and BMI change since the age of 20 years were not associated with lymphatic malignancy risk. However, the rate ratio of lymphatic malignancies per 4-unit increase in BMI at 20 years of age was 1.13 (95% confidence interval (CI): 1.01, 1.25). The rate ratio of lymphatic malignancies per 5-cm increase in height was 1.08 (95% CI: 1.02, 1.15). For diffuse large-cell lymphoma, follicular lymphoma, and chronic lymphocytic leukemia, the relative risks were 1.19 (95% CI: 1.07, 1.33), 1.15 (95% CI: 0.95, 1.40), and 1.09 (95% CI: 0.95, 1.26), respectively, for each 5-cm increase in height. The positive associations among BMI at 20 years of age, height, and the risk of lymphatic malignancies suggest that exposures during early life play a role in the etiology of lymphatic malignancies.

Type 2 diabetes mellitus and risk of non-Hodgkin lymphoma: a systematic review and meta-analysis

Type 2 diabetes mellitus is associated with altered immune function and chronic inflammation. Both of these immune conditions are implicated in the pathogenesis of non-Hodgkin lymphoma. The authors performed a systematic review to summarize findings from the current literature on the association between history of type 2 diabetes mellitus and risk of non-Hodgkin lymphoma. Ten case-control studies and three prospective cohort studies were included in this review. Meta-analysis found that a history of type 2 diabetes mellitus was positively associated with overall non-Hodgkin lymphoma risk. However, there was significant heterogeneity between studies. Study design was an important source of heterogeneity. The rate ratio between type 2 diabetes mellitus and non-Hodgkin lymphoma was found to be 1.18 (95% confidence interval: 0.99, 1.42) among case-control studies and 1.79 (95% confidence interval: 1.30, 2.47) among the prospective cohort studies. Weaknesses were identified in some of the included studies in the areas of case and control selection, measurement of covariates and non-Hodgkin lymphoma, and confounding control. Although a positive association between type 2 diabetes mellitus and risk of non-Hodgkin lymphoma was suggested, the evidence is inconclusive because of methodological limitations of the included case-control studies. More prospective studies with improved control of confounding are needed to confirm these findings.

Weight-based dosing of Yttrium 90 ibritumomab tiuxetan in patients with relapsed or refractory B-cell non-Hodgkin lymphoma

BACKGROUND

Ibritumomab tiuxetan radioimmunotherapy produces durable remissions in patients with relapsed/refractory indolent non-Hodgkin lymphoma. The dosing of Yttrium 90 (90Y)-ibritumomab tiuxetan is based on patient weight and platelet count: 0.4 mCi/kg in patients with a count >or= 150 x 10(9)/L, to a maximum dose of 32 mCi. Patients weighing > 80 kg with platelet counts of >or= 150 x 10(9)/L receive a lower dose per unit of body weight. We evaluated whether this influences the safety or efficacy of treatment.

PATIENTS AND METHODS

Data on efficacy and safety in patients in 3 registration trials who were treated with 90Y ibritumomab tiuxetan at 0.4 mCi/kg (patients weighing <or= 80 kg) or 32 mCi (patients weighing > 80 kg) were collected.

RESULTS

Clinical responses were evaluated in 103 patients weighing <or= 80 kg (median, 70 kg) and 67 patients weighing > 80 kg (median, 95 kg). Sex (41% female vs. 73% male) was the only significantly different characteristic between the patients weighing <or= 80 kg and > 80 kg, respectively. The overall response rates were 79% (<or= 80 kg) and 70% (> 80 kg), and the complete response rates were 28% and 34%, respectively. Median times to progression were 8.9 months (<or= 80 kg) and 9.5 months (> 80 kg). There were no significant differences in efficacy measures or in the incidences of grade 3/4 nonhematologic adverse events, neutropenia, thrombocytopenia, or anemia.

CONCLUSION

The dose of 90Y ibritumomab tiuxetan was < 0.4 mCi/kg in 39% of patients, owing to the 32-mCi dose cap, but the efficacy or safety of 90Y ibritumomab tiuxetan in patients > 80 kg was not affected.