BACKGROUND: Several prognostic factors were proposed to improve early detection of recurrence after liver resection of metastases of colorectal cancer. Circulating tumor cell-related transcripts were evaluated in colorectal cancer patients with conflicting results. The aim of this study was to investigate usefulness of carcinoembryonic antigen CAM5, epidermal growth factor receptor, and ERCC1 transcripts in the bloodstream as predictive factors of recurrence in patients who underwent liver resection for metastases of colorectal cancer.
METHODS: Peripheral blood was collected from 29 patients at the time of the colorectal cancer liver metastasis resection, and from 25 normal controls. Follow-up draws (FUDs) were also performed at 30 days, and 3 and 12 months since surgery. On each sample, carcinoembryonic antigen CAM5, ERCC1, and GAPDH mRNAs were examined by quantitative reverse transcription (qRT).
RESULTS: Carcinoembryonic antigen transcript levels were linearly correlated to the number of spiked cells (qRT analytical limit = five cells). Among 29 patients (20 M/9 F; mean age 63 years (range 32-79), highly significant levels of carcinoembryonic antigen, if compared to the baseline, were detected in those relapsing after surgery (P <0.05). The main differences were between the 1st- and 12th-month FUDs. Significantly higher levels of carcinoembryonic antigen were also detected in patients who died from disease progression during the follow-up (as evaluated at 30 days and 90 days FUDs).
CONCLUSIONS: Blood carcinoembryonic antigen-mRNA absolute copy number overtime variation can represent a valid early predictor of relapse after liver resection in colorectal liver metastases patients. Prospective studies, in the context of large clinical trials, will provide further data to also qualify ERCC1 as a predictive biomarker for decisions on therapeutic strategies.