Effects of a 12-week home-based exercise program on the level of physical activity, insulin, and cytokines in colorectal cancer survivors: a pilot study.

Purpose: The purposes of this study are to examine (1) the feasibility and efficacy of two different home-based exercise protocols on the level of physical activity (PA), and (2) the effect of increased PA via home-based exercise program on biomarkers of colorectal cancer.
Methods: Seventeen patients (age 55.18 ± 13.3 years) with stage II-III colorectal cancer completed the 12-week home-based exercise program. Subjects were randomized into either casually intervened home-based exercise group (CIHE) or intensely intervened home-based exercise group (IIHE). The primary outcome was the level of PA. Furthermore, insulin, homeostasis model assessment of insulin resistance, insulin-like growth factor axis, and adipocytokines were measured.
Results: Both CIHE and IIHE program significantly increased the level of PA at 12 weeks compared to its level at baseline (CIHE, 10.00 ± 8.49 vs. 46.07 ± 45.59; IIHE, 12.08 ± 11.04 vs. 35.42 ± 27.42 MET hours per week). Since there was no difference in PA change between groups (p = 0.511), the data was combined in analyzing the effects of increased PA on biomarkers. Increase in PA significantly reduced insulin (6.66 ± 4.58 vs. 4.86 ± 3.48 μU/ml, p = 0.006), HOMA-IR (1.66 ± 1.23 vs. 1.25 ± 1.04, p = 0.017), and tumor necrosis alpha-α (TNF-α 4.85 ± 7.88 vs. 2.95 ± 5.38 pg/ml, p = 0.004), and significantly increased IGF-1 (135.39 ± 60.15 vs. 159.53 ng/ml, p = 0.007), IGF binding protein (IGFBP)-3 (2.67 ± 1.48 vs. 3.48 ± 1.00 ng/ml, p = 0.013), and adiponectin (6.73 ± 3.07 vs. 7.54 ± 3.96 μg/ml, p = 0.015).
Conclusion: CIHE program was as effective as IIHE program in increasing the level of PA, and the increase in PA resulted in significant change in HOMA-IR, IGF-1 axis, TNF-α, and adiponectin levels in stage II-III colorectal cancer survivors.