The benefits of liver resection for non-colorectal, non-neuroendocrine liver metastases: a systematic review

Defining the benefits of resection of isolated non-colorectal, non-neuroendocrine (NCRNNE) liver metastases is difficult. To better understand the survival benefit in this group of patients, we conducted a systematic review of the previous literature. Medline, Web of Knowledge, and manual searches were performed using search terms, such as "liver resection" and "primary tumor." Inclusion criteria were year > 1990, > five patients, and median survival reported or derived. An expected median survival was calculated from weighted averages of median survivals, and differences were assessed using a permutation test. A total of 7,857 references were identified. Overall 4,735 abstracts were reviewed; 120 manuscripts evaluated and of these, 73 met the study inclusion criteria. The final population consisted of 3,596 patients with renal (n = 234), ovarian (n = 119), testicular (n = 153), adrenal (n = 90), small bowel (n = 28), gallbladder (n = 21), duodenum (n = 38), gastric (n = 481), pancreatic (n = 55), esophageal (n = 23), head and neck (n = 15), and lung (n = 36) cancers, gastrointestinal stromal tumors (GISTs) (n = 106), cholangiocarcinoma (n = 13), sarcoma (n = 189), and melanoma (n = 643). The greatest expected median was 63 months for genitourinary (GU) primaries (n = 549; range 5.4-142 months) followed by 44.4 months for breast cancer (n = 1,013; range 8-74 months), 22.3 months for gastrointestinal cancer (n = 549; range 5-58 months), and 23.7 months for other tumor types (n = 1,082; range 10-72 months). Using a permutation test, we observed that survival was best for patients with GU primaries followed by that for breast cancer patients. Additionally, we also observed that survival was similar for those with cancer of the GI tract and other primary sites. There appears to be a benefit to resection for patients with NCRNNE liver metastases. The degree of survival advantage is predicated by primary site.