Surrogate Role of Kinetic of Perioperative Circulating Cancer Cells (ctcs) in Patients with Liver Metastases (M) of Colorectal Cancer (Crc)

e21086 Background: Kinetic behavior of perioperative CTCs in pts with liver CRC M has been little explored. The aim of this study was to quantified CTCs performance before/just performed and 3 months after radical liver surgery (LS) in pts with CRC M and analyzed the surrogate role of CTCs determinations in DFS and OS. Methods: 7.5 ml of blood were drawn in CellSave tubes. CTCs were isolated and enumerated before/just perfomed and 3 months after radical LS. CTCs were immunomagnetically separated and fluorescently labeled using the CellSearch System (Veridex®/Immunicon Corp.) Results: From February 2009 to December 2011, 35 pts were included. Median age was 61 (45-77); 53.7 % men. Kras status: 66.7% wild-type and 33.3% mutated; 48.6% with synchronous disease. Fong-Criteria (FC) distribution: 31.4% pts with 1 FC, 37.1% pts with 2 FC and 31.4% pts with 3 FC, of whom 60% received neoadjuvant (90% fluoropirimidines-based; 33.3% cetuximab-based; 38% bevacizumab-based) and 77.1% adjuvant treatment. PR and SD were observed in 60% and 40% of pts, respectively. In 70.7% of cases, limited LS were done (68.3% R0, median metastases resected:3) Of the 17 pts analysed, pCR were observed in 2 (12%) with 7 other pts (41%) with major pathological response. With a median of follow-up of 20 months (media 21.3; 95% CI:17.3-41.4) progression disease occurred in 13 pts (55.6% with liver progression), and 5 pts died. Median CTCs was 1 before (0-2: 76%; ≥3: 24%) and just performed surgery (0-2: 65%; ³3: 35%) and 0 in the 3 months determination (0-2: 94.1%; ³3: 5.9%). In the presurgery analysis, DFS was 15 months for the CTCs ≥3 group and 33 months for <3 CTCs (HR: 0.95; 95% CI:0.34-2.64) while in the postsurgery analysis, DFS was 13 months in CTCs ≥3 group and 33 months for <3 CTCs (HR: 1.11; 95% CI:0.37-3.29) CTCs ≥3 group after surgery, OS was 33 months, not having reached in the other groups. Conclusions: There is a marked difference in DFS in favor of pts with CTCs levels 0-2 before and just performed surgery. Our study shows a slight increase in CTCs quantification after LS, instead a significant CTCs decrease was observed after adjuvant therapy. Role of radical LS in kinetic of CTCs should continue to be analysed in future studies.