Background: Energy balance-related factors, such as body mass index (BMI), diet, and physical activity, may influence colorectal cancer etiology through interconnected metabolic pathways, but their combined influence is less clear.
Methods: We used reduced rank regression to derive three energy balance scores that associate lifestyle factors with combinations of prediagnostic, circulating levels of high-sensitivity C-reactive protein (hsCRP), C-peptide, and hemoglobin A1c (HbA1c) among 2,498 participants in the Cancer Prevention Study-II Nutrition Cohort. Among 114,989 participants, we verified 2,228 colorectal cancer cases. We assessed associations of each score with colorectal cancer incidence and by tumor molecular phenotypes using Cox proportional hazards regression.
Results: The derived scores comprised BMI, physical activity, screen time, and 14 food groups, and explained 5.1% to 10.5% of the variation in biomarkers. The HR and 95% confidence interval (CI) for quartile 4 versus 1 of the HbA1c+C peptide-based score and colorectal cancer was 1.30 (1.15-1.47), the hsCRP-based score was 1.35 (1.19-1.53), and the hsCRP, C-peptide, and HbA1c-based score was 1.35 (1.19-1.52). The latter score was associated with non-CIMP tumors (HRQ4vsQ1: 1.59; 95% CI: 1.17-2.16), but not CIMP-positive tumors (P heterogeneity = 0.04).
Conclusions: These results further support hypotheses that systemic biomarkers of metabolic health-inflammation and abnormal glucose homeostasis-mediate part of the relationship between several energy balance-related modifiable factors and colorectal cancer risk.
Impact: Results support cancer prevention guidelines for maintaining a healthful body weight, consuming a healthful diet, and being physically active. More research is needed on these clusters of exposures with molecular phenotypes of tumors.
©2020 American Association for Cancer Research.