Aims: Studies to date on the association between physical activity and non-Hodgkin lymphoma (NHL) risk have not had large enough samples to investigate whether the association differs by NHL subtype. We pooled data from eight case-control studies to examine the association between physical activity and risk of NHL overall and NHL subtypes.
Methods: A total of 5553 cases and 8942 controls were included in the pooled analysis. Physical activity was harmonized across the eight studies and modelled as study-specific tertile groups. Multinomial logistic regression was used to estimate the association between physical activity and NHL subtypes, after adjusting for age, sex, study, ethnicity, education and body mass index.
Results: The risk of overall NHL was 13% lower among participants in the most active tertile group of MVPA compared to the least active tertile group (AOR = 0.87, 95% CI = 0.80, 0.95). Moderate-intensity physical activity alone was not associated with NHL risk. Vigorous-intensity physical activity was associated with a reduced risk of overall NHL, however the association appeared to differ between males and females. No large differences were observed between the NHL subtypes examined (diffuse large B-cell lymphoma, follicular lymphoma, chronic lymphocytic leukaemia/small lymphoctyic lymphoma, marginal zone lymphoma and mature T-cell lymphoma).
Conclusions: Physical activity was associated with a modest risk reduction of overall NHL, which is consistent with recent meta-analyses and pooled cohort analyses. The association between physical activity and NHL does not appear to vary significantly between NHL subtypes.