Relationship between the number of lymph nodes pathologically examined and the prognosis of colorectal cancer by TNM stage

Objective To study the relationship between the number of examined lymph nodes and the prognosis of colorectal cancer by TNM stage. Methods According to the number of examined lymph nodes, 567 patients of colorectal carcinoma who underwent resection were divided into three groups: ≤ 6,7-11 and ≥ 12, the 5-year overall survival rates of three groups were compared. For each TNM stage ( stage Ⅰ -Ⅳ ) , patients were substratified into two groups basing on the number of examined lymph nodes: 0. 05 ) , however, the 5-year survival rates of stage Ⅱ and Ⅲ colorectal cancer in ≥12 group were significantly higher than<12 group(71. 1% vs. 32. 6% ,48. 8% vs. 30. 0% ,P<0. 05) , multivariable analysis revealed that the number of lymph nodes examined was an independent factor of prognosis of stage Ⅱ and Ⅲ colorectal cancer. Conclusions The number of examined lymph nodes significantly influenced the 5-year overall survival rate of TNM stage Ⅱ and Ⅲ colorectal cancer. Key words: Colorectal neoplasm;  Neoplasm staging;  Prognosis;  Lymph node