Effects of a Weight Loss Intervention on Body Mass, Fitness, and Inflammatory Biomarkers in Overweight or Obese Breast Cancer Survivors

Obesity is characterized by chronic mild inflammation and may influence the risk and progression of cancer. The current study is an exploratory analysis of the effect of a weight loss intervention that emphasized increased physical activity on inflammatory cytokines (tumor necrosis factor-alpha [TNF-alpha], interleukin-6 [IL-6], interleukin-8 [IL-8], and vascular endothelial growth factor [VEGF]) at the end of the 16-week intervention period in overweight breast cancer survivors. Study participants averaged 56 years of age (N = 68). Intervention participants (n = 44 vs. 24 controls) participated in a cognitive behavioral therapy-based weight management program as part of an exploratory randomized trial. The intervention incorporated strategies to promote increased physical activity and diet modification. Baseline and 16-week data included height, weight, body composition, physical activity level, and biomarkers IL-6, IL-8, TNF-alpha, and VEGF. Weight loss was significantly greater in the intervention group than controls (-5.7 [3.5] vs. 0.2 [4.1] kg, P < 0.001). Paired t tests noted favorable changes in physical activity level (P < 0.001 intervention, P = 0.70 control), marginally lower IL-6 levels (P = 0.06 intervention, P = 0.25 control) at 16 weeks for participants in the intervention group, and lower TNF-alpha levels for participants in the intervention (P < 0.05) and control groups (P < 0.001). Increased physical activity was associated with favorable changes in IL-6 for participants in the intervention group (R (2) = 0.18; P < 0.03). Favorable changes in cytokine levels were observed in association with weight loss in this exploratory study with overweight breast cancer survivors.