Tu1836 TUMOR AREA AND MICROSCOPIC EXTENT OF INVASION DETERMINE CIRCULATING TUMOR CELL-FREE DNA FRACTION IN PLASMA AND DETECTABILITY OF COLORECTAL CANCER

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.

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Use of Circulating Cell-Free DNA to Guide Precision Medicine in Patients with Colorectal Cancer

Annual Review of Medicine ◽

10.1146/annurev-med-070119-120448 ◽

2021 ◽

Vol 72 (1) ◽

pp. 399-413

Author(s):

Van K. Morris ◽

John H. Strickler

Keyword(s):

Colorectal Cancer ◽

Precision Medicine ◽

Residual Disease ◽

Cost Effective ◽

Patient Specific ◽

Blood Draw ◽

Cell Free Dna ◽

Free Dna ◽

Metastatic Setting ◽

Diagnostic Technology

Patient-specific biomarkers form the foundation of precision medicine strategies. To realize the promise of precision medicine in patients with colorectal cancer (CRC), access to cost-effective, convenient, and safe assays is critical. Improvements in diagnostic technology have enabled ultrasensitive and specific assays to identify cell-free DNA (cfDNA) from a routine blood draw. Clinicians are already employing these minimally invasive assays to identify drivers of therapeutic resistance and measure genomic heterogeneity, particularly when tumor tissue is difficult to access or serial sampling is necessary. As cfDNA diagnostic technology continues to improve, more innovative applications are anticipated. In this review, we focus on four clinical applications for cfDNA analysis in the management of CRC: detecting minimal residual disease, monitoring treatment response in the metastatic setting, identifying drivers of treatment sensitivity and resistance, and guiding therapeutic strategies to overcome resistance.

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