EP1072 - Risk of Metabolic Diseases After Right- vs Left-Sided Colon Cancer Surgery: A Nationwide Cohort Study in Korea

Purpose/Background: While metabolic syndrome increases colorectal cancer risk by 30-40%, the reverse relationship, how surgery affects subsequent metabolic disease development, is poorly understood. Given the distinct characteristics of right- versus left-sided colon cancers, we hypothesized that surgical laterality would differentially impact postoperative metabolic outcomes. This study aimed to compare the incidence of new-onset diabetes mellitus, hypertension, and dyslipidemia after right- versus left-sided colectomy for colon cancer using a nationwide population-based cohort.

Methods/Interventions: We conducted a retrospective cohort study using the Korean Clinical Data Utilization for Research Excellence (K-CURE) database, which links cancer registry, insurance claims, and health screening data. Adults aged ≥30 years with histologically confirmed colon cancer (ICD-10 C18-C19) who underwent colectomy between January 1, 2013, and December 31, 2019, were included. We excluded patients with pre-existing metabolic conditions, metastatic disease, inflammatory bowel disease, or hereditary cancer syndromes. Tumor location was classified as right-sided (cecum through transverse colon) or left-sided (splenic flexure through rectosigmoid junction) based on ICD-10 codes. Primary outcomes were new-onset diabetes mellitus, hypertension, and dyslipidemia occurring >12 months post-surgery. Cox proportional hazards models were adjusted for demographics, lifestyle factors, BMI, waist circumference, SEER stage, and treatment modality. Competing risk models accounted for death.

Results/Outcomes: Among 8,228 patients (mean age 58.8 years; 56.3% male), 3,253 underwent right-sided and 4,975 underwent left-sided colectomy. During a median follow-up of 4.0 years, 358 patients (4.4%) developed diabetes mellitus, 1,050 (12.8%) developed hypertension, and 1,167 (14.2%) developed dyslipidemia. Right-sided colectomy was associated with a 20% lower risk of incident dyslipidemia compared with left-sided colectomy (adjusted HR 0.80; 95% CI 0.71-0.91; P< 0.001). No significant differences were observed for diabetes mellitus (adjusted HR 1.12; 95% CI 0.91-1.39) or hypertension (adjusted HR 0.96; 95% CI 0.85-1.09). The protective association for dyslipidemia was more pronounced in women (HR 0.77), elderly patients ≥65 years (HR 0.64), and those with BMI < 25 kg/m² (HR 0.75). Results remained consistent in sensitivity analyses varying lag periods and follow-up duration.

Conclusion/Discussion: In this nationwide cohort, anatomic laterality of colectomy was differentially associated with metabolic outcomes. Right-sided resection conferred a 20% lower risk of incident dyslipidemia compared with left-sided resection, potentially reflecting differences in bile acid metabolism and microbiome alterations. These findings support enhanced postoperative lipid surveillance for patients undergoing left-sided colectomy and highlight the importance of considering surgical laterality in long-term metabolic risk stratification for colorectal cancer survivors.

Cumulative Incidence of Metabolic Diseases After Right- vs Left-Sided Colectomy
(A) Cumulative incidence of diabetes mellitus (log-rank P = .259).

(B) Cumulative incidence of hypertension (log-rank P = .333).

(C) Cumulative incidence of dyslipidemia (log-rank P = .010).
Risk of Metabolic Diseases after Right- vs Left-Sided Colectomy
Abbreviations: CI, confidence interval; HR, hazard ratio; IR, incidence rate; sHR, subdistribution hazard ratio

a Adjusted hazard ratio from multivariable Cox model: adjusted for sex, age, smoking, alcohol consumption, regular physical activity, BMI, waist circumference, SEER stage, and treatment modality

b Subdistribution hazard ratio from competing risk analysis with death as competing event

p-values were calculated using chi-square test for categorical variables