The Role of Conventional TACE (cTACE) and DEBIRI-TACE in Colorectal Cancer Liver Metastases

SIMPLE SUMMARY: Liver metastases of colorectal cancer have an enormous clinical impact and prevalence. As colorectal cancer is one of the most common cancers, such patients are routinely encountered in day-to-day practice. Still, surgery and systemic chemotherapy constitute the first-line therapies depending on clinical setting. However, if patients present with non-resectable liver-only or liver-dominant metastases and/or do not respond to systemic chemotherapy, local therapies based on a vascular approach can be offered by interventional radiologists to achieve local tumor control or to downstage tumor burden. These therapies are generally called transarterial chemoembolization (TACE). Such treatments can also be combined with systemic or other local therapies. Depending on local practice and expertise, TACE can be offered with a combination of chemotherapeutic agents and embolizing agents or drug-eluting beads which embolize the metastases and its feeding vascular supply and release a chemotherapeutic agent over time. In the following review we compare these different approaches in the local therapy of liver metastases of colorectal cancer by presenting representative study results. ABSTRACT: Colorectal cancer (CRC) is one of the most common tumor entities worldwide and a common cause of cancer-associated death. Colorectal cancer liver metastases (CRLM) thereby constitute a severe life-limiting factor. The therapy of CRLM presents a major challenge and surgical resection as well as systemic chemotherapy remain the first-line treatment options. Over the years several locoregional, vascular- and image-based treatments offered by interventional radiologists have emerged when conventional therapies fail, or metastases recurrence occurs. Among such options is the conventional/traditional transarterial chemoembolization (cTACE) by local injection of a combination of chemotherapeutic- and embolic-agents. A similar treatment is the more recent irinotecan-loaded drug-eluting beads TACE (DEBIRI-TACE), which are administered using the same approach. Numerous studies have shown that these different types of chemoembolization can be applied in different clinical settings safely. Furthermore, such treatments can also be combined with other local or systemic therapies. Unfortunately, due to the incoherent patient populations of studies investigating TACE in CRLM, critics state that the definite evidence supporting positive patient outcomes is still lacking. In the following article we review studies on conventional and DEBIRI-TACE. Although highly dependent on the clinical setting, prior therapies and generally the study population, cTACE and DEBIRI-TACE show comparable results. We present the most representative studies on the different chemoembolization procedures and compare the results. Although there is compelling evidence for both approaches, further studies are necessary to determine which patients profit most from these therapies. In conclusion, we determine TACE to be a viable option in CRLM in different clinical settings. Nevertheless, a multidisciplinary approach is desired to offer patients the best possible care.