Retrospective Study
Copyright ©The Author(s) 2018. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Dec 7, 2018; 24(45): 5167-5178
Published online Dec 7, 2018. doi: 10.3748/wjg.v24.i45.5167
Nomogram to predict overall survival after gallbladder cancer resection in China
Yi Bai, Zhi-Song Liu, Jian-Ping Xiong, Wei-Yu Xu, Jian-Zhen Lin, Jun-Yu Long, Fei Miao, Han-Chun Huang, Xue-Shuai Wan, Hai-Tao Zhao
Yi Bai, Jian-Ping Xiong, Wei-Yu Xu, Jian-Zhen Lin, Jun-Yu Long, Han-Chun Huang, Xue-Shuai Wan, Hai-Tao Zhao, Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, Beijing 100730, China
Zhi-Song Liu, Fei Miao, Department of Statistics, Tianjin University of Finance and Economics Pearl River College, Tianjin 301811, China
Author contributions: Bai Y, Liu ZS, and Xiong JP contributed equally to this work; Bai Y conceived the research, collected and analyzed the clinical data, and wrote the manuscript that led to the submission; Xu WY, Xiong JP, and Huang HC helped to collect the clinical data and followed the patients; Liu ZS, Lin JZ, Long JY, and Miao F helped to analyze the data; Zhao HT and Wan XS revised the manuscript; Zhao HT provided financial support for this work; Zhao HT is the corresponding author; All authors read and approved the final manuscript.
Supported by Chinese Academy of Medical Sciences Innovation Fund for Medical Science, No. 2017-I2M-4-003; International Science and Technology Cooperation Projects, No. 2015DFA30650 and No. 2016YFE0107100; Capital Special Research Project for Health Development, No. 2014-2-4012; Beijing Natural Science Foundation, No. L172055; and National Ten-thousand Talent Program and Beijing Science and Technology Cooperation Special Award Subsidy Project.
Correspondence author to: Hai-Tao Zhao, MD, Professor, Department of Liver Surgery, Peking Union Medical College Hospital, Chinese Academy of Medical Sciences and Peking Union Medical College, 1 Shuaifuyuan, Wangfujing, Beijing 100730, China. zhaoht@pumch.cn
Telephone: +86-10-69156042 Fax: +86-10-69156043
Received: September 19, 2018
Peer-review started: September 19, 2018
First decision: October 16, 2018
Revised: October 23, 2018
Accepted: November 9, 2018
Article in press: November 9, 2018
Published online: December 7, 2018
Processing time: 79 Days and 0.4 Hours
Abstract
AIM

To integrate clinically significant variables related to prognosis after curative resection for gallbladder carcinoma (GBC) into a predictive nomogram.

METHODS

One hundred and forty-two GBC patients who underwent curative intent surgical resection at Peking Union Medical College Hospital (PUMCH) were included. This retrospective case study was conducted at PUMCH of the Chinese Academy of Medical Sciences and Peking Union Medical College (CAMS & PUMC) in China from January 1, 2003 to January 1, 2018. The continuous variable carbohydrate antigen 19-9 (CA19-9) was converted into a categorical variable (cCA19-9) based on the normal reference range. Stages 0 to IIIA were merged into one category, while the remaining stages were grouped into another category. Pathological grade X (GX) was treated as a missing value. A multivariate Cox proportional hazards model was used to select variables to construct a nomogram. Discrimination and calibration of the nomogram were performed via the concordance index (C-index) and calibration plots. The performance of the nomogram was estimated using the calibration curve. Receiver operating characteristic (ROC) curve analysis and decision curve analysis (DCA) were performed to evaluate the predictive accuracy and net benefit of the nomogram, respectively.

RESULTS

Of these 142 GBC patients, 55 (38.7%) were male, and the median and mean age were 64 and 63.9 years, respectively. Forty-eight (33.8%) patients in this cohort were censored in the survival analysis. The median survival time was 20 months. A series of methods, including the likelihood ratio test and Akaike information criterion (AIC) as well as stepwise, forward, and backward analyses, were used to select the model, and all yielded identical results. Jaundice [hazard ratio (HR) = 2.9; 95% confidence interval (CI): 1.60-5.27], cCA19-9 (HR = 3.2; 95%CI: 1.91-5.39), stage (HR = 1.89; 95%CI: 1.16-3.09), and resection (R) (HR = 2.82; 95%CI: 1.54-5.16) were selected as significant predictors and combined into a survival time predictive nomogram (C-index = 0.803; 95%CI: 0.766-0.839). High prediction accuracy (adjusted C-index = 0.797) was further verified via bootstrap validation. The calibration plot demonstrated good performance of the nomogram. ROC curve analysis revealed a high sensitivity and specificity. A high net benefit was proven by DCA.

CONCLUSION

A nomogram has been constructed to predict the overall survival of GBC patients who underwent radical surgery from a clinical database of GBC at PUMCH.

Keywords: Nomogram; Survival; Prognosis; Gallbladder cancer; Resection

Core tip: A nomogram including jaundice, carbohydrate antigen 19-9 (CA19-9), American Joint Committee on Cancer tumor node metastasis stage, and incisional margin status was built to predict the survival of gallbladder cancer patients who underwent curative resection at Peking Union Medical College Hospital. After calibration and verification, this model was shown to have high predictive accuracy and good performance.