Effect of number of resected lymph node on the prognosis of patients with node negative colorectal cancer

Objective To evaluate the long term effect of the number of resected lymph nodes on the prognosis of patients with node negative colorectal cancer. Method Fourty two patients with colorectal cancer were surgically treated and pathology revealed no microscopic nodal involvement. These patients were divided into two groups based on the number of harvested lymph nodes. The prognosis was analyzed retrospectively. Results The 5 year survival rate of the patients with more than 50 harvested lymphatic nodes was significantly higher than that with 50 or less than 50 harvested nodes (100% vs 78 4%,P=0 027). Recurrence occurred in 5 cases and 3 cases died within 5 years in the patients with 50 or less than 50 harvested nodes, while no recurrence and death occurred in the patients with more than 50 harvested nodes. Conclusion Prophylactic lymph node dissection can potentially prolong the survival time of the patients with node negative colorectal cancer.