Circulating tumor DNA and circulating tumor cells as predictor of outcome in the PRODIGE14-ACCORD21-METHEP2 phase II trial

Abstract : Background: We prospectively detected circulating tumor DNA (ctDNA) and circulating tumor cells (CTC) levels in patients (pts) included in the PRODIGE14-ACCORD21-METHEP2 randomized phase II trial. Methods: The trial enrolled colorectal cancer pts with potentially resectable liver metastases & no prior treatment; the primary endpoint was the rate of R0/R1 liver metastases resection achieved by 1st line regimen (targeted therapies & bi- vs tri-chemotherapy; Ychou, ASCO 2016). Blood samples were collected at inclusion, after 1 month of therapy and before any liver metastases surgery. CTCs (CellSearch) & ctDNA (ddPCR, BioRad) were detected in an experienced laboratory (Inst. Curie). Results: 153 pts had at least one blood analysis. High CTC count (≥3 CTC/7.5ml) was detected in 25/132 pts (19%) at baseline and associated with synchronous...