Comparison of Oncologic Outcomes after Mesocolic Resection in Right- and Left-Sided Colon Cancer.

[CONTEXT] Colorectal cancer represents the third leading cause of cancer-related mortality worldwide. Emerging evidence suggests distinct biological differences between right-sided colon cancer (RCC) and left-sided colon cancer (LCC), although their prognostic significance remains controversial.

[AIMS] To compare clinicopathological features and oncological outcomes between RCC and LCC following mesocolic resection and to identify independent prognostic factors.

[SETTING AND DESIGN] A retrospective cohort study was conducted at a tertiary center between January 2010 and December 2020.

[METHODS AND MATERIALS] A total of 948 patients with colon adenocarcinoma underwent curative resection and were categorized as RCC (n = 335) or LCC (n = 613), with analysis of demographic, pathological, and survival data focusing on overall survival and disease-free survival endpoints.

[STATISTICAL ANALYSIS USED] Continuous variables were compared using t-test or Mann-Whitney U test. Categorical variables were analyzed using Chi-square or Fisher's exact test. Univariate and multivariate Cox regression was performed to identify prognostic factors.

[RESULTS] RCC patients were older (62.6 ± 14.8 vs 59.3 ± 14.4 years, P < 0.001) and more frequently female (48.1% vs 37.0%, P < 0.001). RCC tumors showed more aggressive characteristics: poor differentiation (15.8% vs 7.7%), advanced T-stage (97.6% vs 83.9%), and higher KRAS mutations (53.4% vs 37.4%) (all P < 0.001). At median follow-up of 78.4 months, RCC demonstrated inferior survival with OS 79.1% vs 85.0% (P = 0.031) and DFS 74.0% vs 78.0% (P = 0.042). Multivariate analysis confirmed right-sided location as an independent adverse prognostic factor (Hazard Ratio = 1.45, 95% Confidence Interval: 1.05-2.01, P = 0.024).

[CONCLUSIONS] RCC showed more aggressive features and worse survival than LCC, suggesting tumor sidedness as an independent prognostic factor.