Lymph Node Distribution Patterns and Oncologic Outcomes: A Propensity Score-Matched Retrospective Comparison of Right Hemicolectomy versus Ileocecal Resection in Stage III Right-Sided Colon Cancer

Background Right hemicolectomy (RHC) and ileocecal resection (ICR) are two widely used surgical approaches for right-sided colon cancer. However, controversies persist regarding their differences in lymph node (LN) dissection completeness, LN metastasis patterns, and long-term oncologic outcomes in patients with stage III disease. This study aimed to compare LN distribution, surgical outcomes, and survival profiles between RHC and ICR in patients with stage III right-sided colon cancer. Methods A retrospective analysis was conducted on patients with primary right-sided colon cancer who underwent RHC or ICR at a large oncology center in Japan. Propensity score matching (PSM) was applied to balance baseline characteristics between the two groups at a 1:1 ratio. Comparisons were made regarding LN metastasis rates at different stations (pericolic, intermediate, and apical LNs), surgical outcomes, 5-year overall survival (OS), cancer-specific survival (CSS), relapse-free survival (RFS), and recurrence patterns. Results A total of 216 patients in the RHC group and 223 patients in the ICR group were enrolled. After PSM, 185 patients were included in each group. The mean number of excised lymph nodes was significantly higher in the RHC group than in the ICR group both before (36.0 ± 15.0 vs. 26.4 ± 10.6, p < 0.001) and after PSM (36.0 ± 13.8 vs. 26.0 ± 10.7, p < 0.001). The D1 nodal metastasis rate was significantly lower in the RHC group both before (13.9% vs. 4.0%, p < 0.001) and after PSM (13.0% vs. 4.3%, p = 0.005). No significant differences were observed in 5-year OS (70.8% vs. 62.7%, p = 0.137), CSS (77.4% vs. 69.4%, p = 0.190), or RFS (72.2% vs. 71.4%, p = 0.526) between the two groups after PSM. Multivariate logistic regression analysis revealed that histology type (poorly differentiated, signet ring, or mucinous carcinoma), venous invasion, and pN stage were independent prognostic factors for OS, while pN stage was an independent prognostic factor for RFS. A high carcinoembryonic antigen (CEA) level was identified as a common independent high-risk factor for OS, CSS, and RFS. Recurrence patterns (involving the liver, lung, lymph nodes, peritoneum, etc.) were similar between the two groups (all non-significant [N.S]). Conclusion For stage III right-sided colon cancer, RHC achieves a higher number of excised lymph nodes compared with ICR. However, the number of metastatic lymph nodes does not differ significantly between the two groups, and there are no significant differences in long-term oncologic outcomes. The selection of surgical procedure should be individualized based on tumor location, size, and patient-specific factors.