Is complete liver resection without resection of synchronous lung metastases justified?

Advances in multidisciplinary care are changing the prognostic impact of colorectal lung metastases. Resection of colorectal liver metastases (CLM) may benefit patients with synchronous lung metastases even when lung metastases are not resected. The aim of this study was to investigate the survival of patients undergoing complete resection of CLM in the setting of unresected lung metastases.

We compared survival among 98 patients who underwent resection of CLM with unresected lung metastases, 64 who received only chemotherapy for limited colorectal liver and lung metastases, and 41 who underwent resection of both liver and lung metastases. Prognostic factors were investigated in the patients who underwent resection of CLM only.

The 3-year/5-year overall survival (OS) rates of patients with CLM resection only (42.9 %/13.1 %) were better than those of patients treated with chemotherapy only (14.1 %/1.6 %; p < 0.01) but worse than those of patients with resection of liver and lung metastases (68.9 %/56.9 %; p < 0.01). Multivariate analysis of patients with CLM resection only revealed that KRAS mutation [hazard ratio (HR) 2.10; 95 % confidence interval (CI) 1.21-3.64; p < 0.01] and rectal primary tumor (HR 1.72; 95 % CI 1.02-2.88; p = 0.04) were independent predictors of worse OS. Survival of patients without these risk factors was similar to that of patients with curative metastasectomy.

Complete resection of metastases remains the primary goal of treatment for stage IV colorectal cancer. Resection of CLM without resection of lung metastases is associated with an intermediate survival between that of patients treated with palliative and curative intent and should be considered in selected patients.