Summary
This phase II/III trial studies how well circulating tumor deoxyribonucleic acid (ctDNA) testing in the blood works to identify patients with stage IIA colon cancer who might benefit from additional treatment with chemotherapy after surgery. ctDNA are small pieces of genetic materials (DNA) that are shed by tumors into the blood. Finding ctDNA in the blood means that there are very likely small amounts of cancer remaining after surgery that may not be detectable using other tests, such as medical imaging. Testing for ctDNA levels may help identify patients with colon cancer who benefit from receiving chemotherapy after surgery. It is not yet known whether giving additional treatment with chemotherapy after surgery to patients who test positive for ctDNA and are at low risk for cancer recurrence would extend their time without disease compared to the usual approach (active surveillance).