We conducted a systematic review of the published literature to critically assess benefits and risks of the use of preoperative chemotherapy in patients presenting with colorectal liver metastases.
In many centers, chemotherapy is used before hepatic resection of colorectal metastases, even in the presence of a single lesion. Application of chemotherapy requires clear conceptual distinction between patients presenting with resectable lesions (neoadjuvant) versus patients presenting with unresectable lesions, for which chemotherapy is used to reach a resectable situation (downsizing).
The literature (PubMed) was systematically reviewed for publications related to liver surgery and chemotherapy according to the methodology recommended by the Cochrane Collaboration.
For unresectable liver metastases, combination regimens result in enhanced tumor response and resectability rates up to 30%, although the additional benefit from targeted agents such as bevacizumab or cetuximab is marginal. For resectable lesions, studies on neoadjuvant chemotherapy failed to convincingly demonstrate a survival benefit. Most reports described increased postoperative complications in a subset of patients due to parenchymal alterations such as chemotherapy-associated steatohepatitis or sinusoidal obstruction syndrome.
Preoperative standard chemotherapy can be recommended for downsizing unresectable liver metastases, but not for resectable lesions, for which adjuvant chemotherapy is preferred.