What defines 'cure' after liver resection for colorectal metastases? Results after 10 years of follow-up

Background: During the last two decades, resection of colorectal liver metastases (CLM) in selected patients has become the standard of care, with 5-year survival rates of 25-58%. Although a substantial number of actual 5-year survivors are reported after resection, 5-year survival rates may be inadequate to evaluate surgical outcomes because a significant number of patients experience a recurrence at some point. Objectives: This study aimed to analyse longterm results and prognostic factors in liver resection for CLM in patients with complete 10-year follow-up data. Methods: A total of 369 patients who underwent liver resection for CLM between 1985 and 1998 were identified from a bi-institutional database. Postoperative deaths and patients with extrahepatic disease were excluded. Clinicopathological prognostic factors were analysed using univariate and multivariate analyses. Results: The sample included 309 consecutive patients with complete 10-year follow-up data. Five-and 10-year overall survival rates were 32% and 23%, respectively. Overall, 93% of recurrences occurred within the first 5 years of follow-up, but 11% of patients who were disease-free at 5 years developed later recurrence. Multivariate analysis demonstrated four independent negative prognostic factors for survival: more than three metastases; a positive surgical margin; tumour size >5 cm, and a clinical risk score >2. Conclusions: Five-year survival rates are not adequate to evaluate surgical outcomes of patients with CLM. Approximately one-third of actual 5-year survivors suffer cancer-related death, whereas patients who survive 10 years appear to be cured of disease.