Tumor size as a prognostic factor in patients with stage IIa colon cancer

Background: The aim of this study was to identify stage II colon cancer patients with a high risk of recurrence. Methods: All patients who underwent surgery for stage II colon cancer (CC) were retrospectively enrolled and sub-grouped according to TNM staging (IIa-b-c) and stage IIa in high (IIaHR) and low risk (IIaLR) according to pathologic features.The primary outcomes measured were the 5-year overall survival (OS) and disease-free survival (DFS). Results: A total of 214 patients were reviewed. Only a maximum tumor diameter<4 cm in the IIaLR group was associated with a higher recurrence rate than a large tumor size (5-year DFS 71.7%vs.87.6%, p = 0.028).The DFS in the large IIaLR CC group was better than that in the IIaHR and IIb-c groups (5-year DFS: 92.7%vs.79.3%, p = 0.023). In contrast, the recurrence rate in the small IIaLR CC group was similar to that in the IIaHR, IIb-c stage CC group. Conclusions: In stage IIa CC evaluation of the tumor size as a prognostic factor may help identify patients who could benefit from additional postoperative therapy.