Purpose: Prolonged survival after two-stage resection (TSR) of advanced colorectal liver metastases (CLM) may be the result of selection of best responders to chemotherapy. The impact of complete resection in this well-selected group is controversial.
Patients and methods: Data on 890 patients undergoing resection and 879 patients who received only chemotherapy for CLM were collected prospectively. We used intent-to-treat analysis to evaluate the survival of patients who underwent TSR. Additionally, we evaluated a cohort of nonsurgically treated patients selected to mirror the TSR population: colorectal metastases with liver-only disease, objective response to chemotherapy, and alive 1 year after chemotherapy initiation.
Results: Sixty-five patients underwent the first stage of TSR; 62 patients fulfilled the inclusion criteria for the medical group. TSR patients had a mean of 6.7 ± 3.4 CLM with mean size of 4.5 ± 3.1 cm. Nonsurgical patients had a mean of 5.9 ± 2.9 CLM with mean size of 5.4 ± 3.4 cm (not significant). Forty-seven TSR patients (72%) completed the second stage. Progression between stages was the main cause of noncompletion of the second stage (61%). After 50 months median follow-up, the 5-year survival rate was 51% in the TSR group and 15% in the medical group (P = .005). In patients who underwent TSR, noncompletion of TSR and major postoperative complications were independently associated with worse survival.
Conclusion: TSR is associated with excellent outcome in patients with advanced CLM as a result of both selection by chemotherapy and complete resection of metastatic disease.