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

## TL;DR

Radiotherapy can help avoid surgery in some metastatic rectal cancer patients, offering a non-operative option that preserves the organ and improves quality of life.

## Contribution

This review highlights the potential of radiotherapy for non-operative management and organ preservation in metastatic rectal cancer.

## Key findings

- Radiotherapy can be used as a curative or palliative option in managing metastatic rectal cancer.
- Biomarkers like circulating tumor DNA can help identify patients likely to benefit from radiotherapy.
- Non-operative management may improve patient quality of life, though more data on patient satisfaction is needed.

## Abstract

The pivotal role of radiotherapy in integrating non-operative management in the treatment of resectable and unresectable metastatic rectal cancer. cCR: clinical complete response; CRT: chemo-radiotherapy; NOM: non-operative approach.

•Radiotherapy offers an opportunity for non-operative management and organ preservation in metastatic rectal cancer.•Radiotherapy has the potential to be integrated into the management of patients with metastatic rectal cancer as a curative or palliative option.•Optimized biomarkers can identify patients likely to benefit from radiotherapy in organ preservation.

Radiotherapy offers an opportunity for non-operative management and organ preservation in metastatic rectal cancer.

Radiotherapy has the potential to be integrated into the management of patients with metastatic rectal cancer as a curative or palliative option.

Optimized biomarkers can identify patients likely to benefit from radiotherapy in 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.