The combined effects of comorbidities can cause cancer incidence, while the effects of individual conditions, alone, might not. This study was conducted to investigate the joint impact of comorbidities on cancer incidence. The dietary score for energy-adjusted intake was calculated by applying a Gaussian graphical model and was then categorized into tertiles representing light, normal, and heavy eating behaviors. The risk point for cancer, according to the statuses of blood pressure, total cholesterol, fasting glucose, and glomerular filtration rate was computed from a Cox proportional hazard model adjusted for demographics and eating behavior. The comorbidity risk score was defined as the sum of the risk points for four comorbidity markers. We finally quantified the hazard ratios (HRs) and 95% confidence intervals (CIs) for the association between the strata of the comorbidity risk score and cancer incidence. A total of 13,644 subjects were recruited from the Cancer Screenee Cohort from 2007-2014. The comorbidity risk score was associated with cancer incidence in a dose-dependent manner (HR = 2.15, 95% CI = 1.39, 3.31 for those scoring 16-30 vs. those scoring 0-8, P-trend < 0.001). Subgroup analysis still showed significant dose-dependent relationships (HR = 2.39, 95% CI = 1.18, 4.84 for males and HR = 1.99, 95% CI = 1.11, 3.59 for females, P-trend < 0.05). In summary, there was a dose-dependent impact of comorbidities on cancer incidence; Highlights: Previous studies have generally reported that hypertension, hypercholesterolemia, diabetes, and chronic kidney disease might predispose patients to cancer. Combining these chronic diseases into a single score, this study found a dose-dependent association between the data-driven comorbidity risk score and cancer incidence.
Keywords: Gaussian graphical model; cancer incidence; comorbidity risk score; dietary score.