Lifetime physical inactivity is associated with increased risk for Hodgkin and non-Hodgkin lymphoma: A case-control study.

BACKGROUND: Although physical activity is a well-established risk factor for several cancer types, studies evaluating its association with lymphoma have yielded inconclusive results. In such cases where physical activity is not clearly associated with cancer risk in a dose-dependent manner, investigators have begun examining physical inactivity as an independent exposure of interest. METHODS: Associations of self-reported, lifetime physical inactivity with risk of developing Hodgkin lymphoma (HL) and non-Hodgkin lymphoma (NHL) were evaluated in a hospital-based case control study using data from the Patient Epidemiology Data System at Roswell Park Comprehensive Cancer Center. Participants included 87 patients with HL and 236 patients with NHL as well as 348 and 952 cancer-free controls, respectively. Multivariable-adjusted logistic regression models were fit to calculate odds ratios (OR) and 95% confidence intervals (CI) estimating the association between physical inactivity and lymphoma risk. RESULTS: We observed significant, positive associations between lifetime recreational physical inactivity and risk of both HL (OR = 1.90, 95% CI: 1.15-3.15) and NHL (OR = 1.35, 95% CI: 1.01-1.82). CONCLUSIONS: The current analysis provides evidence for a positive association between physical inactivity and risk of both HL and NHL. These results add to a growing body of research suggesting that lifetime physical inactivity may be an important independent, modifiable behavioral risk factor for cancer.