LiverMetSurvey: Analysis of clinicopathologic factors associated with the efficacy of preoperative chemotherapy in 2,122 patients with colorectal liver metastases.

3521 Background: LiverMetSurvey is an international, internet-based registry designed to assess the efficacy of multimodality treatment options for colorectal liver metastases (CLM) by analyzing outcomes following hepatic resection (HR) in a large number of patients. METHODS Data were analyzed for the 2,122 patients entered into LiverMetSurvey by six hepatobiliary centers from inception to August 2004 (HR: 1974 to 2004; 1,306 men: 816 women; mean age: 61 years). The distributions of potential prognostic factors including age, sex, primary tumor site, timing of metastasis diagnosis, tumor number, diameter of the largest metastasis, bilaterality, and treatment with chemotherapy were compared to survivals using univariate and multivariate statistics. RESULTS Metastases originated in the colon in 69% of patients and were synchronous (diagnosed within 3 mo of primary tumor treatment) in 49% of patients. 34% of patients had ≥ 3 metastases and tumors were distributed bilaterally in 43% of cases. The mean size of the largest metastasis was 41.8 mm. 55% of patients were treated with preoperative systemic chemotherapy. Following resection, 60-day mortality was 1.2% and median, 5-year, and 10-year overall survivals (OS) were 46 mo, 42%, and 26%, respectively. Variables independently associated with poor prognosis included number of metastases > 3 (p<0.0001), bilateral metastases (p=0.0002), and size of the largest metastasis > 5 cm (p=0.03). Preoperative chemotherapy (PC) did not appear to benefit patients with solitary CLM (5-yr OS: PC 45% vs. no PC 58%), but was associated with improved survival in patients with > 5 metastases (5-yr OS: PC 22% vs. no PC 12%). CONCLUSIONS Assessment of outcomes for the first 2,122 registrants to LiverMetSurvey not only confirms the prognostic importance of intrahepatic tumor burden, but also indicates that the ability of preoperative systemic chemotherapy to improve survivals is limited to patients with multiple (> 5) metastases. In addition, this analysis demonstrates the potential for LiverMetSurvey, which is now prospectively enrolling patients from over 40 centers, to determine the therapeutic value of current and future treatment strategies. No significant financial relationships to disclose.