A-27: Landmark Trials in Rectal Cancer Surgery

Abstract

The management of rectal cancer has evolved substantially over the past three decades through landmark clinical trials that have progressively defined the principles of oncological surgery, the role and timing of radiotherapy and chemotherapy, and the adoption of minimally invasive techniques. The concept of Total Mesorectal Excision (TME) revolutionized local control, while subsequent trials established the role of neoadjuvant treatment in appropriately selected patients. More recently, Total Neoadjuvant Therapy (TNT), advances in minimally invasive surgery, and organ-preservation strategies have challenged traditional treatment pathways and raised important questions regarding the optimal timing, extent, and even necessity of surgery. This review examines key randomized controlled trials and significant prospective studies that have shaped rectal cancer management, including those addressing TME, neoadjuvant therapy and TNT, minimally invasive surgery, robotic and transanal approaches, and organ preservation. Key oncological, pathological, and surgical outcomes are summarized, with emphasis on their contribution to changes in contemporary practice. The transition from conventional rectal excision to standardized TME established the quality of the mesorectal plane as a fundamental determinant of oncological outcome. Subsequent trials demonstrated the importance of appropriate patient selection and timing of neoadjuvant treatment, while studies of laparoscopic, robotic, and transanal approaches explored ways to overcome the technical challenges of operating within the confined pelvis without compromising oncological quality. More recent trials have shifted the focus towards TNT, selective application of radiotherapy, and organ preservation. Collectively, these studies have transformed rectal cancer management from a procedure-centered approach into an increasingly individualized, multidisciplinary treatment pathway. Understanding the evidence generated by these landmark trials provides a framework for interpreting current practice and highlights the continuing evolution of rectal cancer management.