# Regional Therapies Utilized in Treating Unresectable Colorectal Adenocarcinoma with Peritoneal Metastases

## TL;DR

This review explores regional therapies for treating unresectable colorectal cancer that has spread to the peritoneum, focusing on non-surgical options for patients with limited treatment choices.

## Contribution

The paper highlights the current state of non-surgical regional therapies for unresectable peritoneal metastases and suggests future research directions.

## Key findings

- Regional therapies can help control symptoms and slow disease progression in some patients.
- Non-surgical regional treatments have only been studied in early-phase clinical trials.
- There is a significant gap in effective therapies for patients with unresectable peritoneal metastases.

## Abstract

Metastatic spread of colorectal cancer to the peritoneal lining is a difficult disease to treat and often has poor outcomes. Some patients may benefit from surgery and heated chemotherapy delivered directly into the abdomen; however, many patients have disease that is unresectable. For these patients, treatment options are limited, and standard systemic chemotherapy has reduced effectiveness. This review examines the multitude of regional treatments that deliver therapy directly into the abdominal cavity for patients with unresectable disease. These approaches aim to control symptoms, slow disease progression, and in some cases reduce tumor burden enough to allow future cytoreductive surgery. We summarize early clinical studies evaluating these therapies and discuss their potential benefits and limitations.

Colorectal peritoneal metastases portend a poor prognosis when compared to other isolated sites of metastatic disease. The advent of regional therapies, including cytoreductive surgery, have improved outcomes for patients with peritoneal carcinomatosis. However, these options are typically only available in patients deemed to have resectable disease. For patients with unresectable peritoneal disease, non-surgical regional therapy has only been studied in early-phase clinical trials. This represents a gap in therapy in a population with a desperate need. In this review, we highlight the current limited data, as well as postulate on the future direction of regional therapies in patients with unresectable peritoneal metastases from colorectal adenocarcinoma.