Body Size, Recreational Physical Activity, and B-Cell Non-Hodgkin Lymphoma Risk Among Women in the California Teachers Study

Background: Despite the existence of numerous biologic pathways potentially linking increased physical activity to decreased risk of hematologic cancers, the associations between physical activity and subtypespecific hematologic cancers have not been comprehensively quantified.Methods: We conducted a systematic review and meta-analysis of physical activity in relation to subtypespecific hematologic cancers. We summarized the data from 23 eligible studies (15 cohort and eight casecontrol studies) and estimated summary relative risks (RR) and 95% confidence intervals (CI) using randomeffects models.Results: When comparing high versus low physical activity levels, the RR for non-Hodgkin lymphoma was 0.91 (95% CI, 0.82-1.00), for Hodgkin lymphoma it was 0.86 (95% CI, 0.58-1.26), for leukemia it was 0.97 (95% CI, 0.84-1.13), and for multiple myeloma it was 0.86 (95% CI, 0.68-1.09). When focusing on subtypes of nonHodgkin lymphoma, the RR for diffuse large B-cell lymphoma was 0.95 (95% CI, 0.80-1.14) and for follicular lymphoma it was 1.01 (95% CI, 0.83-1.22). In an exploratory analysis combining all hematologic cancers, high versus low physical activity levels yielded a statistically significant RR of 0.93 (95% CI, 0.88-0.99).Conclusions: Physical activity showed statistically nonsignificant associations with risks of non-Hodgkin lymphoma, Hodgkin lymphoma, multiple myeloma, and leukemia. These findings may not represent a true lack of associations given the variation in high versus low physical activity definitions, the quality of physical activity assessments, and the variability in hematologic cancer classification schemes in individual studies.Impact: Physical activity is unrelated to risks of subtype-specific hematologic cancers. Cancer Epidemiol Biomarkers Prev; 23(5); 833-46. Ó2014 AACR.

Section: Resultsmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Physical Activity in Relation to Risk of Hematologic Cancers: A Systematic Review and Meta-analysis

Jochem

Leitzmann

Keimling

et al. 2014

“…Whereas height is determined by genetic as well as environmental factors, such as nutritional status during childhood and adolescence, weight and BMI reflect nutritional status during adulthood as well. A number of case-control and cohort studies have evaluated associations between these anthropometric factors and risk of lymphoid neoplasms in Western populations (5)(6)(7)(8)(9)(10)(11)(12). Although several of these showed a positive association between height and lymphoid neoplasm risk (5-9), others did not (10)(11)(12).…”

Section: Introductionmentioning

confidence: 99%

Association of Anthropometric Characteristics with the Risk of Malignant Lymphoma and Plasma Cell Myeloma in a Japanese Population: A Population-Based Cohort Study

Kanda

Matsuo

Inoue

et al. 2010

Background: Although Asian and Western populations differ markedly in anthropometric characteristics and the incidence of malignant lymphoma and plasma cell myeloma, few studies have evaluated the associations between these variables among Asian populations.Methods: We conducted a large-scale, population-based prospective study in a Japanese cohort that included 45,007 men and 49,540 women ages 40 to 69 years at baseline. During an average follow-up period of 13 years, 257 cases of malignant lymphoma and 88 of plasma cell myeloma were identified. Hazard ratios (HR) and 95% confidence intervals (95% CI) were estimated with the use of a Cox regression model adjusted for potential confounders.Results: Compared with the 1st quartile, categorization in the 4th quartile for height showed a positive association with lymphoid neoplasm risk (HR, 1.38; 95% CI, 1.00-1.91), and the association was significant among men (HR, 1.72; 95% CI, 1.11-2.66). A similar trend was observed for subcategories of malignant lymphoma, plasma cell myeloma, and non-Hodgkin lymphoma, albeit the associations were weak due to the small number of subjects in each category. In contrast, weight and body mass index were not associated with risk of lymphoid neoplasm.Conclusions: Height was positively associated with risk of lymphoid neoplasm in a Japanese population. Impact: Our data suggested that early life exposure to growth-related hormones, such as insulin-like growth factors and growth hormones, or genetic factors relating to height may affect the risk of lymphoid neoplasm. Cancer Epidemiol Biomarkers Prev; 19(6); 1623-31. ©2010 AACR.

“…Only one previous study has examined lifetime non-occupational physical activity in relation to NHL risk, with the results indicating no association (14). In regard to physical activity intensity, although it is possible that vigorous-intensity physical activity is required to reduce NHL risk, another explanation is that measures of vigorous-intensity physical activity are better able to distinguish between active and inactive participants.…”

Section: Discussionmentioning

confidence: 99%

“…Although two studies have found that physical activity may have a greater influence on follicular lymphoma risk than diffuse large B-cell lymphoma risk (17,18), most studies have found little variation between physical activity and the risk of different NHL subtypes (14,16,(19)(20)(21)(22)(23). It remains unclear whether the association between physical activity and NHL risk varies by subtype.…”

Section: Discussionmentioning

confidence: 99%

Lifetime Physical Activity and the Risk of Non-Hodgkin Lymphoma

Boyle

Gallagher

Gascoyne

et al. 2015

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 vigorousintensity 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 moderateintensity 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. Cancer Epidemiol Biomarkers Prev; 24(5); 873-7. Ó2015 AACR.