Value of tumor diameter to preoperative carcinoembryonic antigen ratio in evaluating prognosis of non-metastatic colorectal cancer patients

Objective To explore the value of tumor diameter to preoperative carcinoembryonic antigen (CEA) ratio (TCR) in predicting prognosis of patients with non-metastatic colorectal cancer. Methods The clinical data of 144 patients with colorectal cancer in Hainan Hospital of PLA General Hospital between July 2012 and December 2017 were retrospectively analyzed. Patients were divided into the low TCR group and the high TCR group according to the optimal value of TCR in predicting the disease-free survival (DFS) determined by the receiver operating characteristic curve (ROC). The clinicopathological features of both groups were analyzed, and the influencing factors of DFS were also analyzed by using Cox proportional hazard model. Results ROC analysis showed that TCR had a certain value in predicting DFS, and area under the curve (AUC) was 0.614 (95% CI 0.507-0.722); when the value of TCR was set at 0.690, the sensitivity and specificity of predicting the 3-year DFS rate was 46.3% and 70.9%, respectively. According to 0.690 of TCR, there were 50 cases in the low TCR ( 0.05). Univariate analysis showed that TCR, preoperative CEA level and TNM stage played a role in predicting DFS of patients (all P < 0.05), while Cox multivariate analysis indicated that TCR < 0.690 (HR = 2.369, 95% CI 1.279-4.388, P = 0.006) and Ⅲ stage in TNM stage (HR = 2.214, 95% CI 1.346-3.640, P = 0.002) were the independent risk factors of influencing DFS (all P < 0.01). The 3-year DFS rate of patients in the low TCR group was lower than that of those in the high TCR group (62.0% vs. 83.0%, P = 0.007). Conclusion TCR could have a certain value in judging the prognosis of non-metastatic colorectal cancer patients, and low TCR patients have a poorer prognosis. Key words: Colorectal neoplasms; Tumor diameter; Carcinoembryonic antigen; Disease-free survival; Prognosis