WITHDRAWN: Resection versus no intervention or other surgical interventions for colorectal cancer liver metastases

About one in four of patients with metastatic colorectal cancer have metastases isolated to the liver, of which 10-25% are eligible for ablation of the liver metastases, improving the 5-year survival rate. Treatments include hepatic resection and non-surgical tumor ablation using cryosurgery and radiofrequency thermal ablation. Although new modalities allow safe ablation of liver metastases without the need for surgical intervention, there are still no clear guidelines on the appropriate management of patients with colorectal cancer and hepatic metastases.

The primary objectives were to compare resection of liver metastases to no intervention and other modalities of intervention (including cryosurgery and radiofrequency ablation), in terms of the benefits and harms for each intervention.

We identified randomized controlled trials from MEDLINE, Embase, and the Cochrane Controlled Trials Register up to October 2006, based upon the search strategy developed for MEDLINE, and revised appropriately for each database. In addition, references were scrutinized in identified eligible trials.

We only considered randomized controlled trials reporting patients of any age and sex, who have had curative surgery for adenocarcinoma of the colon or rectum, diagnosed with liver metastases that are candidates for liver resection, i.e., with no evidence of primary or metastatic cancer elsewhere.

Two reviewers independently extracted data and assessed trial quality using a data-extraction form designed for this review. Discrepancies were resolved in consensus.

Only one trial fulfilled our inclusion criteria. The data of this 10-year prospective, randomized clinical trial suggest that hepatic cryosurgery is effective in the treatment of resectable and non-resectable liver metastases. The results show intra-operative tumor reduction (> or = 90% < or = 97%) and extended higher survival in these patients. The study indicated a 5-year and 10-year survival rate of 44% and 19% after cryosurgery, respectively. However, it was not possible to separate out and unravel the outcomes data that related only to the participants (66.6%) with liver metastases from colorectal cancer as opposed to those with liver metastases from other primary tumors.

There is currently insufficient evidence to support a single approach, either surgical or non-surgical for the management of colorectal liver metastases. Therefore, treatment decisions should continue to be based on individual circumstances and clinician's experience. We concede that local ablative therapies are probably useful, but they need to be further evaluated in a randomized controlled trial.