Insufficient Lymph Node Dissection Is an Independent Risk Factor for Postoperative Cancer Death in Patients Undergoing Surgery for Stage II Colorectal Cancer

BACKGROUND: Surgical resection is the most effective treatment for patients with stage II colorectal cancer (CRC). However, a few patients with early-phase CRC suffer postoperative cancer death. AIMS: To investigate the risk factors for postoperative cancer death in patients who undergo surgery for stage II CRC. METHODS: Prognostic significance was analyzed by χ(2) test, univariate analyses, Kaplan-Meier analysis and log-rank test using clinicopathological factors from the database. RESULTS: A total of 205 patients with stage II CRC were evaluated. Age (≤ 65/>65 years), venous invasion (negative/positive), number of dissected lymph nodes (≤ 9/≥ 10), grade of lymph node dissection (sufficient/insufficient) and albumin level (< 3.5/≥ 3.5 g/dl) were associated with shorter overall survival. Univariate analysis of the clinicopathological factors revealed that only the grade of lymph node dissection (sufficient/insufficient) was associated with postoperative cancer death (odds ratio 2.993, 95% confidence interval 1.216-7.368, p = 0.017).Kaplan-Meier analysis and log-rank test revealed that the group with insufficient lymph node dissection had a higher incidence of postoperative cancer death than the group with sufficient dissection (p < 0.001). CONCLUSIONS: Insufficient lymph node dissection is an independent risk factor for postoperative cancer death in patients who undergo surgery for stage II CRC.