Treatment of colorectal and non-colorectal liver metastases: rationale for neoadjuvant therapeutic concepts

Abstract

Liver metastases represent the most common secondary malignant liver disease. Data regarding the incidence of colorectal and non-colorectal liver metastases are rare due to insufficient documentation in a register. Results regarding neoadjuvant therapy are limited and mostly from retrospective analyses. A summary and rating of the rationale for neoadjuvant therapeutic concepts for colorectal and non-colorectal liver metastases were performed. The analysis was based on European and American guidelines and included publications in both German and English languages. The results and recommendations were summarized and areview based on the literature is given. Neoadjuvant treatment of liver metastases is performed with heterogeneous intentions. The selection of biologically favorable tumors as well as the conversion of primarily non-operable into resectable metastases of the liver are classical reasons for neoadjuvant treatment. The rationale for neoadjuvant treatment of colorectal and especially for non-colorectal liver metastases cannot be answered in aconsistently coherent way with respect to the current status quo of the literature and guidelines. The creation of treatment strategies in clinical settings follows criteria, such as patterns of metastases, complexity of the resection and biological factors (metachronous/synchronous metastases, prognostic factors). Neoadjuvant treatment in the context of conversion therapy is the standard procedure for metastasized colorectal cancer. The biological selection of favorable tumors as the basis for neoadjuvant treatment of resectable lesions is not a consistently used standard for colorectal cancer. Non-colorectal liver metastases are resected only as part of individual concepts.