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Blood Tests (ctDNA Levels) for the Improvement of Watch & Wait Management for Patients with Stage II-III Rectal Cancer, SNOWW Trial

Trial Status: approved

This clinical trial studies how well blood tests looking at circulating tumor deoxyribonucleic acid (ctDNA) levels work in improving detection of cancer regrowth during watch & wait (WW) surveillance in patients with stage II or III rectal cancer. Rectal cancer is the 3rd most common cancer in both adult males and females in the United States. Stages II and III rectal cancer are routinely and initially treated with a combination of chemotherapy and pelvic radiation therapy called total neoadjuvant therapy (TNT). Rectal cancer patients with a response after TNT may now be given the option to defer definitive surgery and undergo close WW surveillance instead of surgery. This surveillance is conducted over 5 years and includes scheduled imaging and clinical tests/procedures to look for cancer regrowth. ctDNA are fragments of tumor cell DNA that circulate in the patient's bloodstream. ctDNA has been useful in the early detection of various types of cancer regrowth and often plays a role in colorectal cancer treatment decision-making. ctDNA testing may help improve the ability of doctors to identify the ideal rectal cancer patient to elect to WW management and to detect cancer regrowth during WW management as soon as possible.