AIM: To evaluate the oncologic outcomes of primary and post-irradiated early stage rectal cancer and the effectiveness of adjuvant chemotherapy for rectal cancer patients. METHODS: Eighty-four patients with stage Ⅰ rectal cancer after radical surgery were studied retrospectively and divided into ypstage Ⅰ group (n = 45) and pstage Ⅰ group (n = 39), according to their preoperative radiation, and compared by univariate and multivariate analysis. RESULTS: The median follow-up time of patients was 70 mo. No significant difference was observed in diseaseprogression between the two groups. The 5-year disease-free survival rate was 84.4% and 92.3%, respectively (P = 0.327) and the 5-year overall survival rate was 88.9% and 92.3%, respectively, for the two groups (P = 0.692). The disease progression was not significantly associated with the pretreatment clinical stage in ypstage Ⅰ group. The 5-year disease progression rate was 10.5% and 19.2%, respectively, for the patients who received adjuvant chemotherapy and for those who rejected chemotherapy in the ypstage Ⅰ group (P = 0.681). CONCLUSION: The oncologic outcomes of primary and post-irradiated early stage rectal cancer are similar. Patients with ypstage Ⅰ rectal cancer may slightly benefit from adjuvant chemotherapy. AIM: To evaluate the oncologic outcomes of primary and post-irradiated early stage rectal cancer and the effectiveness of adjuvant chemotherapy for rectal cancer patients. METHODS: Eighty-four patients with stage I rectal cancer after radical surgery were studied retrospectively and divided into ypstage I RESULTS: The median follow-up time of patients was 70 mo. No significant difference was observed in the group (n = 45) and pstage group I (n = 39), according to their preoperative radiation, and compared by univariate and multivariate analysis. The 5-year disease-free survival rate was 84.4% and 92.3%, respectively (P = 0.327) and the 5-year overall survival rate was 88.9% and 92.3%, respectively, for the two groups ( P = 0.692). The disease progression was not significantly associated with the pretreatment clinical stage in ypstage group I. The 5-year disease progression rate was 10.5% and 19.2%, respectively, for the patients who receive d adjuvant chemotherapy and for those who rejected chemotherapy in the ypstage group I (P = 0.681). CONCLUSION: The oncologic outcomes of primary and post-irradiated early stage rectal cancer are similar. Patients with ypstage I rectal cancer may slightly benefit from adjuvant chemotherapy .