Management of colorectal liver metastases: past, present, and future.

The decade that began the new century (2000–2010) was marked by reports highlighting major success in the treatment of liver metastases from colorectal cancer. The EORTC (European Organisation for Research and Treatment of Cancer) trial was the first significant randomized trial examining the utility of short course preand postoperative chemotherapy with a direct comparison with surgery alone [1]. Multiple centers indicated improved long-term survivals of more than 50% at 5 years after resection [2–4]. These improved survivals have resulted from a combination of better patient selection, increased efficacy of systemic chemotherapy and improvements in surgical technique including the development of creative solutions to difficult anatomic problems [5–9]. These results have encouraged surgeons to continue to expand the indications for surgery in patients with colorectal liver metastases. As surgeons have continued to expand the indications for resection in this patient population, predictably, several new controversies have arisen. It appears that, during the decade that we have just entered, it will be our charge to approach these issues and to develop consensus as to the most appropriate treatment of these patients. Certainly, if the past is a predictor of the future, innovative oncologic approaches will continue to develop, and challenge established guidelines [10–12]. With the publication of the EORTC trial, we were afforded strong evidence in support of the combined use of perioperative chemotherapy for patients with colorectal liver metastases. This trial documented that the use of combined chemotherapy and surgery was associated with a 25% reduction in the risk of relapse after resection of colorectal liver metastases [1, 13]. The uniform application of such an approach has since been debated for some subsets of patients. As with any clinical problem, the disease presents in a bell curve distribution both in terms of tumor burden and tumor biology. There are certainly patients with limited disease (i.e., solitary superficial liver metastases) and even some patients with multiple metastases, but favorable (i.e., slow-growing) tumor biology who may not demonstrate the benefit of systemic chemotherapy for many years after their operation. This reality has led some authors to comment that these patients may not receive immediate benefit from systemic therapy and may possibly be harmed by the delivery of such therapy [14]. As such, it is important to note that the EORTC trial did not focus on high-risk patients, but on patients with more limited disease, including the majority (52%) of patients presenting with solitary metastases and a median size of the liver metastases smaller than 5 cm. Further evidence to support the perioperative approach can be found in nearly every report of long-term survivals in these patients, which consistently indicate that two-thirds of the patients alive harbor visible recurrent disease [1, 15, 16]. Certainly, patients with low-volume disease share an important favorable prognostic factor and in general have the best outcomes among all patients operated for colorectal liver metastases. However, current data do not support a different approach for this subset of patients [17] and perioperative chemotherapy should be considered standard of care as it decreases the risk of recurrence after resection [13]. At the other end of the liver metastases spectrum are the patients with advanced metastatic disease and multiple bilateral liver metastases. Indeed, in our not so distant past T. A. Aloia J.-N. Vauthey (&) Department of Surgical Oncology, The University of Texas MD Anderson Cancer Center, 1515 Holcombe Boulevard, Unit 444, Houston, TX 77030, USA e-mail: jvauthey@mdanderson.org