Stoma-free Survival After Rectal Cancer Resection With Anastomotic Leakage: Development and Validation of a Prediction Model in a Large International Cohort

OBJECTIVE: This study aimed to develop and validate a prediction model (STOMA-score) for one-year stoma-free survival in rectal cancer (RC) patients with anastomotic leakage (AL). BACKGROUND: AL after RC resection often results in a permanent stoma. METHODS: This international retrospective cohort study (TENTACLE-Rectum) encompassed 216 participating centres, and included patients who developed AL after RC surgery between 2014-2018. Clinically relevant predictors for one-year stoma-free survival were included in uni- and multivariable logistic regression models. The STOMA-score was developed and internally validated in a cohort of patients operated between 2014-2017, with subsequent temporal validation in a 2018 cohort. The discriminative power and calibration of the models' performance were evaluated. RESULTS: This study included 2499 AL patients; 1954 in the development cohort and 545 in the validation cohort. Baseline characteristics were comparable. One-year stoma-free survival was 45.0% in the development cohort and 43.7% in the validation cohort. The following predictors were included in the STOMA-score: sex, age, ASA-classification, body mass index, clinical M-disease, neoadjuvant therapy, abdominal- and transanal approach, primary defunctioning stoma, multivisceral resection, clinical setting in which AL was diagnosed, postoperative day of AL diagnosis, abdominal contamination, anastomotic defect circumference, bowel wall ischemia, anastomotic fistula, retraction and reactivation leakage. The STOMA-score showed good discrimination and calibration (c-index 0.71, 95%CI 0.66-0.76). CONCLUSION: The STOMA-score consists of eighteen clinically relevant factors and estimates the individual risk for one-year stoma-free survival in patients with AL after RC surgery, which may improve patient counselling and give guidance when analyzing efficacy of different treatment strategies in future studies.Nynke G. Greijdanus, Kiedo Wienholts, Sander Ubels, Kevin Talboom, Gerjon Hannink, Albert Wolthuis, Francisco B. de Lacy, Jérémie H. Lefevre, Michael Solomon, Matteo Frasson, Nicolas Rotholtz, Quentin Denost, Rodrigo O. Perez, Tsuyoshi Konishi, Yves Panis, Martin Rutegård, Roel Hompes, Camiel Rosman, Frans van Workum, Pieter J. Tanis, Johannes H.W. de Wilt, and TENTACLE-Rectum Collaborative Group (Collaborators: Bremers, Andreas J.A. ... Kroon, Hidde M. ... Sammour, Tarik ... et al.

Predictive Factors and Risk Model for Positive Circumferential Resection Margin Rate After Transanal Total Mesorectal Excision in 2653 Patients With Rectal Cancer.

The aim of this study was to determine the incidence of, and preoperative risk factors for, positive circumferential resection margin (CRM) after transanal total mesorectal excision (TaTME). TaTME has the potential to further reduce the rate of positive CRM for patients with low rectal cancer, thereby improving oncological outcome. A prospective registry-based study including all cases recorded on the international TaTME registry between July 2014 and January 2018 was performed. Endpoints were the incidence of, and predictive factors for, positive CRM. Univariate and multivariate logistic regressions were performed, and factors for positive CRM were then assessed by formulating a predictive model. In total, 2653 patients undergoing TaTME for rectal cancer were included. The incidence of positive CRM was 107 (4.0%). In multivariate logistic regression analysis, a positive CRM after TaTME was significantly associated with tumors located up to 1 cm from the anorectal junction, anterior tumors, cT4 tumors, extra-mural venous invasion (EMVI), and threatened or involved CRM on baseline MRI (odds ratios 2.09, 1.66, 1.93, 1.94, and 1.72, respectively). The predictive model showed adequate discrimination (area under the receiver-operating characteristic curve >0.70), and predicted a 28% risk of positive CRM if all risk factors were present. Five preoperative tumor-related characteristics had an adverse effect on CRM involvement after TaTME. The predicted risk of positive CRM after TaTME for a specific patient can be calculated preoperatively with the proposed model and may help guide patient selection for optimal treatment and enhance a tailored treatment approach to further optimize oncological outcomes

Predictive Factors and Risk Model for Positive Circumferential Resection Margin Rate after Transanal Total Mesorectal Excision in 2653 Patients with Rectal Cancer

The aim of this study was to determine the incidence of, and preoperative risk factors for, positive circumferential resection margin (CRM) after transanal total mesorectal excision (TaTME). Background: TaTME has the potential to further reduce the rate of positive CRM for patients with low rectal cancer, thereby improving oncological outcome. Methods: A prospective registry-based study including all cases recorded on the international TaTME registry between July 2014 and January 2018 was performed. Endpoints were the incidence of, and predictive factors for, positive CRM. Univariate and multivariate logistic regressions were performed, and factors for positive CRM were then assessed by formulating a predictive model. Results: In total, 2653 patients undergoing TaTME for rectal cancer were included. The incidence of positive CRM was 107 (4.0%). In multivariate logistic regression analysis, a positive CRM after TaTME was significantly associated with tumors located up to 1 cm from the anorectal junction, anterior tumors, cT4 tumors, extra-mural venous invasion (EMVI), and threatened or involved CRM on baseline MRI (odds ratios 2.09, 1.66, 1.93, 1.94, and 1.72, respectively). The predictive model showed adequate discrimination (area under the receiver-operating characteristic curve >0.70), and predicted a 28% risk of positive CRM if all risk factors were present. Conclusion: Five preoperative tumor-related characteristics had an adverse effect on CRM involvement after TaTME. The predicted risk of positive CRM after TaTME for a specific patient can be calculated preoperatively with the proposed model and may help guide patient selection for optimal treatment and enhance a tailored treatment approach to further optimize oncological outcomes