Revisiting the ASA physical status classification: Differential associations with long-term survival in abdominal cancer surgery

BACKGROUND: This cohort study evaluates the American Society of Anesthesiologists (ASA) Physical Status Classification as a predictor for long-term survival after major abdominal cancer surgery and reassesses its conventional use for perioperative risk assessment. METHOD: Using data from the Norwegian Registry for Gastrointestinal Surgery (NORGAST), we identified patients who underwent formal resection for colorectal cancer, as well as patients undergoing surgery for pancreatic or liver malignancies, between January 2016 and December 2023. Log-rank analyses were used to assess survival differences according to ASA class. RESULTS: This study analyzed 20,784 patients undergoing surgery for colorectal cancer and 4792 patients undergoing surgery for pancreatic or liver malignancy. After excluding patients who died within 90 days postoperatively, 20,244 colorectal and 4702 pancreatic/liver patients remained for survival analysis. ASA class was associated with postoperative morbidity, mortality, and length of stay after colorectal cancer surgery; however, a very large number of patients was required to demonstrate a modest percentage-point differences. In both log-rank and multivariable analyses, ASA class was strongly associated with long-term survival after colorectal cancer surgery (p < 0.001) and after resection for pancreatic and liver malignancies (p < 0.001). This association persisted across age-matched cohorts, and ASA class outperformed age in multivariable survival analysis. CONCLUSION: Although the ASA classification demonstrates clear relevance in predicting long-term survival after major abdominal cancer surgery, its clinical utility for perioperative risk assessment appears limited. Despite criticisms regarding subjectivity and moderate inter-rater reliability, ASA classification determined by experienced professionals may capture patient factors beyond documented comorbidities, potentially reflecting underlying disease severity or patient resilience.