Retrospective Study
Copyright ©The Author(s) 2021. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Clin Cases. Jul 26, 2021; 9(21): 5860-5872
Published online Jul 26, 2021. doi: 10.12998/wjcc.v9.i21.5860
Development and validation of a prognostic nomogram for colorectal cancer after surgery
Bo-Wen Li, Xiao-Yu Ma, Shuang Lai, Xin Sun, Ming-Jun Sun, Bing Chang
Bo-Wen Li, Shuang Lai, Xin Sun, Bing Chang, Department of Gastroenterology, The Frist Hospital of China Medical University, Shenyang 110000, Liaoning Province, China
Xiao-Yu Ma, Ming-Jun Sun, Department of Gastroenterology and Endoscopy, The Frist Hospital of China Medical University, Shenyang 110000, Liaoning Province, China
Author contributions: Li BW performed the research and wrote the paper; Ma XY supervised the report; Lai S and Sun X contributed to the analysis; Sun MJ and Chang B proposed the idea and clinical advice.
Supported by Science and Technology Support Program of Shenyang, No. 20-205-4-094.
Institutional review board statement: The experimental data are from the Surveillance, Epidemiology, and End Results (SEER) database, not clinical cases from any medical institutions. Therefore, our research does not need to be approved by an ethics committee.
Informed consent statement: The experimental data are from the Surveillance, Epidemiology, and End Results (SEER) database, not clinical cases from any medical institutions. Because the data is anonymous and the patients’ personal privacy information is not available, informed consent is not required.
Conflict-of-interest statement: The authors have no conflict of interest to declare.
Data sharing statement: No additional data are available.
Open-Access: This article is an open-access article that was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution NonCommercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/Licenses/by-nc/4.0/
Corresponding author: Bing Chang, MD, Assistant Professor, Department of Gastroenterology, The Frist Hospital of China Medical University, No. 155 Nanjing North Street, Shenyang 110000, Liaoning Province, China. cb000216@163.com
Received: February 25, 2021
Peer-review started: February 25, 2021
First decision: May 1, 2021
Revised: May 17, 2021
Accepted: May 25, 2021
Article in press: May 25, 2021
Published online: July 26, 2021
Processing time: 146 Days and 5.7 Hours
Abstract
BACKGROUND

A nomogram is a diagram that aggregates various predictive factors through multivariate regression analysis, which can be used to predict patient outcomes intuitively. Lymph node (LN) metastasis and tumor deposit (TD) conditions are two critical factors that affect the prognosis of patients with colorectal cancer (CRC) after surgery. At present, few effective tools have been established to predict the overall survival (OS) of CRC patients after surgery.

AIM

To screen out suitable risk factors and to develop a nomogram that predicts the postoperative OS of CRC patients.

METHODS

Data from a total of 3139 patients diagnosed with CRC who underwent surgical removal of tumors and LN resection from 2010 to 2015 were collected from the Surveillance, Epidemiology, and End Results program. The data were divided into a training set (n = 2092) and a validation set (n = 1047) at random. The Harrell concordance index (C-index), Akaike information criterion (AIC), and area under the curve (AUC) were used to assess the predictive performance of the N stage from the American Joint Committee Cancer tumor-node-metastasis classification, LN ratio (LNR), and log odds of positive lymph nodes (LODDS). Univariate and multivariate analyses were utilized to screen out the risk factors significantly correlating with OS. The construction of the nomogram was based on Cox regression analysis. The C-index, receiver operating characteristic (ROC) curve, and calibration curve were employed to evaluate the discrimination and prediction abilities of the model. The likelihood ratio test was used to compare the sensitivity and specificity of the final model to the model with the N stage alone to evaluate LN metastasis.

RESULTS

The predictive efficacy of the LODDS was better than that of the LNR based on the C-index, AIC values, and AUC values of the ROC curve. Seven independent predictive factors, namely, race, age at diagnosis, T stage, M stage, LODDS, TD condition, and serum carcinoembryonic antigen level, were included in the nomogram. The C-index of the nomogram for OS prediction was 0.8002 (95%CI: 0.7839-0.8165) in the training set and 0.7864 (95%CI: 0.7604-0.8124) in the validation set. The AUC values of the ROC curve predicting the 1-, 3-, and 5-year OS were 0.846, 0.841, and 0.825, respectively, in the training set and 0.823, 0.817, and 0.835, respectively, in the validation test. Great consistency between the predicted and actual observed OS for the 1-, 3-, and 5-year OS in the training set and validation set was shown in the calibration curves. The final nomogram showed a better sensitivity and specificity than the nomogram with N stage alone for evaluating LN metastasis in both the training set (-4668.0 vs -4688.3, P < 0.001) and the validation set (-1919.5 vs -1919.8, P < 0.001) through the likelihood ratio test.

CONCLUSION

The nomogram incorporating LODDS, TD, and other risk factors showed great predictive accuracy and better sensitivity and specificity and represents a potential tool for therapeutic decision-making.

Keywords: Colorectal cancer; Nomogram; Tumor deposit; Lymph node; Prognosis; Surveillance, Epidemiology, and End Results program

Core Tip: The Surveillance, Epidemiology, and End Results (SEER) program has provided material and data support for evidence-based clinical studies. At present, few studies have concentrated on developing a predictive model for the outcomes of colorectal cancer (CRC) after surgery. We developed a nomogram to predict the probability of overall survival at different times in patients with CRC based on the SEER database. Compared with the N staging from the American Joint Committee on Cancer tumor-node-metastasis classification, the nomogram incorporating the log odds of positive lymph nodes and tumor deposit in this study showed better sensitivity and specificity.