Abstract: Objective To investigate the differences in clinicopathological characteristics, relative mortality risk, and patterns of first recurrence/metastasis after radical resection between right-sided colon cancer （RCC） and left-sided colon cancer （LCC）. Methods A retrospective analysis was conducted on 90 patients with pathologically confirmed colon cancer who underwent radical resection at our hospital between June 2018 and June 2021. Based on tumor location, patients were divided into the RCC group （n=45） and the LCC group （n=45）. Clinical features, pathological parameters, risk of death, and sites of recurrence or metastasis were compared. Statistical analysis included t-tests, chi-square tests, and Cox proportional hazards modeling. Follow-up continued until June 2024. Results There were no significant differences between the two groups in age, sex, tumor markers[carcinoembryonic antigen （CEA） and carbohydrate antigen （CA） 19-9], or rates of curative surgery and adjuvant chemotherapy （P>0.05）. RCC patients had significantly larger tumor diameters （P=0.004） and higher numbers of lymph nodes retrieved （P=0.001） than LCC patients. Multivariate Cox proportional hazards modeling analysis revealed that elevated CEA, tumor stage Ⅲ-Ⅳ, larger tumor size, lymphovascular invasion, and presence of tumor nodules were independent predictors of poor prognosis （P<0.05）, whereas radical resection was associated with improved survival （P<0.05）. Although differences in first recurrence/metastasis sites were not statistically significant （P>0.05）, RCC showed a higher tendency toward peritoneal dissemination, while anastomotic recurrence was more frequent in LCC. Conclusion RCC and LCC demonstrate significant differences in tumor size, lymph node dissection number, and prognostic risk. RCC is associated with bigger tumor burden and poorer survival outcomes, highlighting the need for enhanced preoperative assessment and postoperative surveillance. Tumor laterality, biological behavior, and risk factors for prognosis should be considered in the development of precision treatment and follow-up strategies for colon cancer patients.

Key words: Colon cancer, Right-sided colon cancer, Left-sided colon cancer, Clinicopathological features, Mortality risk, Recurrence and metastasis patterns, Cox regression analysis