Local Treatments in the Unresectable Patient with Colorectal Cancer Metastasis: A Review from the Point of View of the Medical Oncologist

SIMPLE SUMMARY: Local treatments represent a potential curative approach in the patient with liver metastases of colorectal origin. It is important for all the team involved in patient care to know and understand which patients are suitable for this approach and the expected results of these treatments. This review is intended to focus (without neglecting the technical issues of these techniques) in clinical aspects, to help other clinicians to seek the best available evidence to guide their decisions and advocate for the best possible treatment for the patient. ABSTRACT: For patients with isolated liver metastases from colorectal cancer who are not candidates for potentially curative resections, non-surgical local treatments may be useful. Non-surgical local treatments are classified according to how the treatment is administered. Local treatments are applied directly on hepatic parenchyma, such as radiofrequency, microwave hyperthermia and cryotherapy. Locoregional therapies are delivered through the hepatic artery, such as chemoinfusion, chemoembolization or selective internal radiation with Yttrium 90 radioembolization. The purpose of this review is to describe the different interventional therapies that are available for these patients in routine clinical practice, the most important clinical trials that have tried to demonstrate the effectiveness of each therapy and recommendations from principal medical oncologic societies.