The role of radiotherapy in the management of metastatic rectal cancer: A narrative review on the opportunities for non-operative management and organ preservation.

About 20% of patients with rectal cancer present with metastatic rectal cancer (MRC). The 5-year relative survival for patients with MRC is about 15%. With emerging systemic therapies, including more effective chemotherapy regimens, immunotherapy, targeted therapies, and radiotherapy as a local option, more patients with advanced rectal cancer are achieving complete clinical response in the primary tumor. Consequently, non-operative management (NOM) through a "watch and wait approach" is becoming increasingly desired. Additionally, improved biomarkers, such as circulating tumor DNA (ctDNA), can improve accuracy in predicting responses to neoadjuvant chemoradiotherapy and monitoring recurrence after achieving complete clinical response. In this narrative review, we examine the current evidence on the role of radiotherapy in the management of MRC, with a focus on NOM and organ preservation strategies. Notably, although several investigations have evaluated various aspects of the NOM approach, there is still limited data regarding patient satisfaction and quality of life. The improved quality of life may be a key factor driving patient preference for NOM, and we also emphasize the data on the impact of NOM on patient's quality of life.