Development and validation of a predictive score of 30-day mortality following proctectomy for rectal cancer: A National Cancer Database analysis

This study aimed to investigate predictors of 30-day mortality after rectal cancer surgery and develop a predictive score using significant independent predictors. A retrospective case-control analysis of the National Cancer Database (2010-2017) was conducted. Patients with stage I-III rectal adenocarcinoma who underwent proctectomy were included. Patients who died within 30 days of surgery were compared to patients alive at 30 days after surgery for patient, disease, and treatment characteristics. Binary logistic regression was used to develop a predictive model; independent predictors of 30-day mortality were incorporated into a predictive risk score and validated using another cohort from the National Cancer Database (2018-2019). 53,651 patients with rectal cancer (60.9% male) were included. Thirty-day mortality was 1.1%. Independent predictors of 30-day mortality were increased age (odds ratio: 1.07, 95% confidence interval: 1.05-1.08), male sex (2.19, 1.61-2.98), Black race (2.16, 1.44-3.25), Charlson score ≥3 (1.86, 1.05-3.3), tumor-node-metastasis stage III (1.66, 1.12-2.46), neoadjuvant systemic treatment (0.523, 0.296-0.925), prolonged hospitalization (1.02, 1.01-1.03), and conversion to open surgery (1.59, 1.13-2.23). A predictive score entailing 3 risk groups was developed. There was a linear trend of increased 30-day mortality across the three groups (0.8% to 1.9% to 4.5%; P < .001). Score specificity in the development and validation datasets was 99.6% and 99.5% and accuracy was 98.7% and 98.8%, respectively. Independent predictors of increased 30-day mortality were incorporated into a risk score with a specificity and accuracy of more than 98%. The score may be used to improve outcomes of high-risk patients by implementing additional strategies to reduce the risk of short-term mortality.