Elderly patients over 80 years undergoing colorectal cancer resection: Development and validation of a predictive nomogram for survival

• Published in: World journal of gastrointestinal surgery Vol. 15; no. 5; pp. 892 - 905
• Main Authors: Chok, Aik Yong, Zhao, Yun, Chen, Hui Lionel Raphael, Tan, Ivan En-Howe, Chew, Desmond Han Wen, Zhao, Yue, Au, Marianne Kit Har, Tan, Emile John Kwong Wei
• Format: Journal Article
• Language: English
• Published: United States Baishideng Publishing Group Inc 27.05.2023
• Subjects: Retrospective Study; Overall survival; Elderly; Nomogram; Prognostic; Colorectal cancer; Risk stratification
• ISSN: 1948-9366; 1948-9366
• DOI: 10.4240/wjgs.v15.i5.892

Surgery remains the primary treatment for localized colorectal cancer (CRC). Improving surgical decision-making for elderly CRC patients necessitates an accurate predictive tool. To build a nomogram to predict the overall survival of elderly patients over 80 years undergoing CRC resection. Two hundred and ninety-five elderly CRC patients over 80 years undergoing surgery at Singapore General Hospital between 2018 and 2021 were identified from the American College of Surgeons - National Surgical Quality Improvement Program (ACS-NSQIP) database. Prognostic variables were selected using univariate Cox regression, and clinical feature selection was performed by the least absolute shrinkage and selection operator regression. A nomogram for 1- and 3-year overall survival was constructed based on 60% of the study cohort and tested on the remaining 40%. The performance of the nomogram was evaluated using the concordance index (C-index), area under the receiver operating characteristic curve (AUC), and calibration plots. Risk groups were stratified using the total risk points derived from the nomogram and the optimal cut-off point. Survival curves were compared between the high- and low-risk groups. Eight predictors: Age, Charlson comorbidity index, body mass index, serum albumin level, distant metastasis, emergency surgery, postoperative pneumonia, and postoperative myocardial infarction, were included in the nomogram. The AUC values for the 1-year survival were 0.843 and 0.826 for the training and validation cohorts, respectively. The AUC values for the 3-year survival were 0.788 and 0.750 for the training and validation cohorts, respectively. C-index values of the training cohort (0.845) and validation cohort (0.793) suggested the excellent discriminative ability of the nomogram. Calibration curves demonstrated a good consistency between the predictions and actual observations of overall survival in both training and validation cohorts. A significant difference in overall survival was seen between elderly patients stratified into low- and high-risk groups ( < 0.001). We constructed and validated a nomogram predicting 1- and 3-year survival probability in elderly patients over 80 years undergoing CRC resection, thereby facilitating holistic and informed decision-making among these patients.