Circulating Tumor Cells in Patients Undergoing Resection of Colorectal Cancer Liver Metastases. Clinical Utility for Long-Term Outcome: A Prospective Trial.

Background: Patients with resected colorectal cancer liver metastases display heterogeneous clinical behavior. The identification of new prognostic factors would help in making more accurate decisions.
Objective: The aim of this study was to evaluate the survival impact of circulating tumor cells (CTCs) in this setting.
Methods: We conducted a prospective study of patients with resected liver metastases of colorectal cancer. Patients were included in the study from February 2009 to January 2013. The CellSearch System™ was employed for the detection of pre- and postsurgery CTCs. A positive test was defined as two or more CTCs/7.5 mL of blood. Recurrence rate, disease-free survival, and overall survival were calculated, and univariate and multivariate analyses were performed.
Results: Forty-four patients were included in our study. After a median follow-up of 60 months (range 28-74), 32 patients experienced recurrence (72.7%). The CTCs number was determined and the test was positive in 8 patients (18.6%) before surgery and 13 patients (29.5%) after surgery. The postoperative detection of CTCs was not related to any clinical outcome; however, the preoperative detection of CTCs was significantly related to behavior. All patients in the preoperative CTC-positive group relapsed, versus 65% in the CTC-negative group (p = 0.051). Disease-free survival was 19 months in the preoperative CTC-negative group versus 7 months in the CTC-positive group (p = 0.01). Additionally, overall survival was 69 months in the preoperative CTC-negative group versus 17 months in the CTC-positive group (p = 0.004). Preoperative CTC count remained significant in multivariate analysis.
Conclusions: In this cohort of colorectal cancer liver metastases patients, the presence of two or more preoperative CTCs was associated with disease progression and poor survival despite complete resection.