Testing the Addition of Total Ablative Therapy to Usual Systemic Therapy Treatment for Limited Metastatic Colorectal Cancer, The ERASur Study

This phase III trial compares total ablative therapy and usual systemic therapy to usual systemic therapy alone in treating patients with colorectal cancer that has spread to up to 4 body sites (limited metastatic). The usual approach for patients who are not participating in a study is treatment with intravenous (IV) (through a vein) and/or oral medications (systemic therapy) to help stop the cancer sites from getting larger and the spread of the cancer to additional body sites. Ablative means that the intention of the local treatment is to eliminate the cancer at that metastatic site. The ablative local therapy will consist of very focused, intensive radiotherapy called stereotactic ablative radiotherapy (SABR) with or without surgical resection and/or microwave ablation, which is a procedure where a needle is temporarily inserted in the tumor and heat is used to destroy the cancer cells. SABR, surgical resection, and microwave ablation have been tested for safety, but it is not scientifically proven that the addition of these treatments are beneficial for your stage of cancer. The addition of ablative local therapy to all known metastatic sites to the usual approach of systemic therapy could shrink or remove the tumor(s) or prevent the tumor(s) from returning.