Insufficient accrual

This pilot trial studies how well serial liquid biopsies work in detecting microsatellite instability in participants with stage IV colorectal cancer. Serial liquid biopsies may help doctors learn better methods to track cancer in the bloodstream and how to use these to improve cancer treatments.

PRIMARY OBJECTIVES:

I. To test the hypothesis that there is high level of concordance between the electrophoretic mobility profile of microsatellite biomarkers in circulating cell-free deoxyribonucleic acid (ccfDNA) versus in primary tumor tissues in patients with colorectal carcinomas displaying microsatellite instability.

II. To test the hypothesis that changes in the electrophoretic mobility profile of microsatellite biomarkers in liquid biopsies from patients with colorectal carcinoma correlate with therapeutic responsiveness measured based on Response Evaluation Criteria in Solid Tumors (RECIST) criteria.

III. To determine whether microsatellite alleles generated as a result of microsatellite instability detectable in liquid biopsy specimens from patients with colorectal carcinoma represent the entire cancer cell population or only a subset of cancer cells differentially affected by genomic instability.

OUTLINE:

Participants undergo collection of blood samples to evaluate microsatellite instability via serial liquid biopsies at baseline, then every 6 weeks and at progression or 9 months.

Inclusion Criteria:

• Patients newly diagnosed with stage IV colorectal cancer and with defined microsatellite instability status before initiation of systemic immunotherapy.
• Trackable cancer-driver mutation in the primary tumor documented before initiation of chemotherapy.
• Zubrod performance status of 0 or 1.
• Patients have measurable disease according to RECIST version (v)1.1.
• Ability to understand and willing to sign a written informed consent.

Exclusion Criteria:

• Severe anemia (hemoglobin [Hb] < 8 g/dL).

Patients newly diagnosed with stage IV colorectal cancer and with defined microsatellite instability status before initiation of systemic immunotherapy will be recruited.