Prognostic Implications of Endoscopic Obstruction in Patients with Pathological Stage II Colon Cancers: a Single-Center Retrospective Cohort Study.

BACKGROUND: The prognostic effect of endoscopic obstruction (eOB) on the survival of stage II colon cancer patients and the role of eOB in guiding postoperative adjuvant chemotherapy of stage II colon cancer are little known. METHODS: In this retrospective, single-center cohort study, patients who had undergone curative surgery and preoperative colonoscope for stage II colon carcinoma were included. The eOB was defined as severe luminal colon obstruction that prevented the standard colonoscope from passing beyond the tumor. The association between eOB and stage II colon cancer survival and the predictive role of eOB for adjuvant chemotherapy were evaluated using multivariate Cox regression analysis. RESULTS: Of 1102 included patients, 616 (55.9%) had eOB and 486 (44.1%) had no eOB. The median follow-up was 49 months (interquartile range, 38-68 months). Kaplan-Meier curves showed that patients with eOB had poor 5-year overall survival (OS; 85.3% vs. 95.3%, p < 0.001) compared to patients without eOB. Five-year disease-free survival (DFS; 78.5% vs. 87.6%, p = 0.004) was also poor in these patients. Multivariate analysis demonstrated eOB was a significant prognostic factor for poor OS (hazard ratio [HR] = 2.531, p < 0.001), but not for DFS (p = 0.081). Even when patients with clinical colonic obstruction were excluded from the population with eOB, the worse OS (HR = 2.262, p = 0.001) was observed. The OS and DFS of eOB patients improved slightly after adjuvant chemotherapy, but there was no statistical significance. CONCLUSIONS: Stage II colon cancer patients with eOB have a poor prognosis. However, whether eOB can guide adjuvant chemotherapy still needs further study.