Ⅱ~Ⅲ期结肠癌根治术后复发危险因素分析及其列线图预测模型的应用价值

Objective: To investigate the risk factors for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer, and application value of a nomogram prediction model. Methods: The retrospective case-control study was conducted. The clinicopathological data of 228 patients with stage Ⅱ-Ⅲ colon cancer who underwent radical resection in the First Affiliated Hospital of Xi'an Jiaotong University from January 2013 to June 2016 were collected. There were 118 males and 110 females, aged from 25 to 87 years, with a median age of 62 years. All patients underwent open or laparoscopic-assisted radical resection of colon cancer. Observation indicators: (1) postoperative tumor recurrence; (2) risk factors analysis for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer; (3) development and evaluation of a nomogram prediction model for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer. Follow-up using outpatient examination and telephone interview was performed to detect postoperative 3-year tumor recurrence up to June 2019. Measurement data with skewed distribution were represented as M (range). Count data were described as absolute numbers, and comparison between groups was analyzed using the Pearson chi-square test or Fisher exact probability. Multivariate analysis was performed using Logistic stepwise regression analysis. The independent risk factors were included into R 3.6.1 software to construct a nomogram prediction model. The receiver operating characteristic curve (ROC) was drawed, and the area under curve (AUC) was used to evaluate discrimination of the nomogram prediction model. The calibration chart with R software was used to evaluate consistency of the nomogram prediction model. Results: (1)Postoperative tumor recurrence: 53 of 228 patients had postoperative tumor recurrence including 19 cases with locoregional recurrence and 34 cases with distant metastasis. Of the 34 patients with distant metastasis, there were 14 cases with liver metastasis, 7 cases with lung metastasis, 4 cases with brain metastasis, and 9 cases with multiple metastasis or isolated metastasis in other sites. The time to recurrence was 12 months (range, 6-19 months). (2) Risk factors analysis for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer:results of univariate analysis showed that bowel obstruction, preoperative carcinoembryonic antigen (CEA) level, ascites, vascular invasion were related factors for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer (χ²=4.463, 13.622, 10.914, 5.911, P<0.05). Pathological N stage was also a related factor for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer (P<0.05). Results of multivariate analysis showed that preoperative CEA level >5 μg/L, ascites, vascular invasion and pathological N stage as stage N1 or N2 were independent risk factors for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer (odds ratio=3.129, 3.071, 7.634, 3.439, 15.467, 95% confidence interval as 1.328-7.373, 1.047-9.007, 1.103-52.824, 1.422-8.319, 3.498-68.397, P<0.05). (3) Development and evaluation of a nomogram prediction model for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer: based on preoperative CEA level, ascites, vascular invasion and pathological N stage of multivariate analysis, a nomogram prediction model for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer was developed using R 3.6.1 software. The nomogram score was 41.7 for preoperative CEA level >5 μg/L, 41.0 for ascites, 74.2 for vascular invasion, 45.1 and 100.0 for pathological N stage as stage N1 and N2, respectively. The total of different scores for risk factors corresponded to the probability of postoperative recurrence. The ROC of nomogram for recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer was drawed,with the AUC of 0.805(95% confidence interval as 0.737-0.873, P<0.05). The calibration chart showed a good consistency between the probability of recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer predicted by nomogram and the actual probability of postoperative recurrence. Conclusions: Preoperative CEA level >5 μg/L, ascites, vascular invasion and pathological N stage as stage N1 or N2 are independent risk factors for tumor recurrence after radical resection of stage Ⅱ-Ⅲ colon cancer. The nomogram prediction model contributes to prediction of the recurrent risks after radical resection of stage Ⅱ-Ⅲ colon cancer.