Exercise training, inflammatory cytokines, and other markers of low-grade inflammation in breast cancer survivors: A systematic review and meta-analysis.

121 Background: Low-grade inflammation, characterized by high cytokine activity, plays a crucial role in tumorigenesis. Further, cytokines and other inflammatory biomarkers are closely implicated in tumor growth, angiogenesis, and metastasis. This metaanalysis of randomized controlled trials estimates the effects of exercise training in the control of the serum levels of cytokines and other inflammatory markers in breast cancer survivors. Methods: PRISMA statement and the Cochrane Handbook were followed. We searched MEDLINE, CENTRAL, EMBASE, Scopus and DARE database to retrieve randomized controlled trials published between 1980- March 2014 providing effect estimates of exercise interventions in the serum levels of cytokines, such as interleukin (IL) -2, IL-6, IL-8, tumoral necrosis factor alpha (TNF-α) and C-reactive protein (CRP) in breast cancer survivors. An Inverse of variance (IV) fixed-effects model was conducted in absence of heterogeneity (I2<50%); otherwise a random-effects model was selected. Me...