Prognostic scoring in colorectal cancer liver metastases: development and validation

HYPOTHESIS: A prognostic scoring system for colorectal cancer liver metastases that is derived from unselected patients referred for hepatic resection would improve the applicability and increase the accuracy of prognostication. DESIGN: Retrospective analysis of prospectively documented data; validation against an unrelated cohort from another institution. The median follow-up was 16.4 months (95% confidence interval, 15.0-17.8 months) (original cohort). SETTING: Two tertiary referral centers at unrelated university hospitals. PATIENTS: Independent prognosticators of survival were derived from 337 patients with colorectal cancer liver metastases referred for consideration of liver resection, and prognostic scores were calculated in 269 patients (79.8%) (original cohort). Calculation of prognostic scores was also applied to 193 patients referred and treated in an unrelated institution (validation cohort). MAIN OUTCOME MEASURES: Kaplan-Meier survival curve analysis (log-rank test) between different prognostic groups in the original and the validation cohorts. RESULTS: Independent prognosticators of survival were Dukes stage, number of metastases, and serum concentrations of carcinoembryonic antigen, alkaline phosphatase, and albumin. Significant differences were found in cumulative overall survival between patients assigned to good, moderate, and poor prognoses in the original and validation cohorts (P<.05). Liver resection improved survival in all prognostic groups. However, no patient with poor prognosis and only 19.7% (13 of 66) of patients with moderate prognosis survived 5 years, compared with 62.5% (10 of 16) of patients with good prognosis (P<.001). CONCLUSIONS: This prognostic scoring system is derived from and can be applied to patients with colorectal cancer liver metastases at the time of referral for consideration of surgery. Patients with poor prognosis have no long-term benefit from curative liver resection and should therefore be considered for combined multimodal treatment.