[The association of metastasis-related indexes of lymph nodes and the prognosis of stage N2b colorectal cancer patients].

To evaluate the prognostic value of lymph node metastasis-related indexes in patients with stage N2b colorectal cancer. Clinicopathologic data of 245 patients with stage N2b colorectal cancer who initially underwent radical operation in Cancer Hospital, Chinese Academy of Medical Sciences between January 2007 and December 2012 were retrospectively analyzed. The prognostic values of several indexes, including number of positive lymph nodes, number of negative lymph nodes, lymph node ratio (LNR) and log odds of positive lymph nodes (LODDS) were analyzed. The 5-year overall survival rate of 245 patients with colorectal cancer was 54.0%, and the 5-year recurrence-free survival rate was 48.5%.Univariate analysis showed that perineural or blood vessel invasion, T stage, postoperative adjuvant therapy, number of positive lymph nodes, number of negative lymph nodes, LNR, and LODDS were significantly associated with the 5-year overall survival of colorectal cancer patients (<0.05). Multivariate cox regression analysis showed that, number of positive lymph nodes, number of negative lymph nodes, LNR, LODDS were all independent prognostic factors for stage N2b colorectal cancer patients (<0.05). The areas under the receiver operating characteristic curve (ROC) curves of number of positive lymph node, number of negative lymph nodes, LNR and LODDS were 0.649, 0.667, 0.690 and 0.683, respectively, however, no statistical significance was observed between the number of negative lymph nodes (=0.622), LNR (=0.178) or LODDS (=0.272) and the number of positive lymph nodes. The number of positive lymph nodes, number of negative lymph nodes, LNR and LODDS were all independent prognostic factors for patients with stage N2b colorectal cancer.