Blood test could revolutionize cancer monitoring

This study is collecting blood samples from 1,000 people with digestive, gynecologic, or breast cancers to see if pieces of tumor DNA floating in the blood (called ctDNA) can help doctors diagnose cancer, predict how the disease will progress, and check if treatments are working. Researchers will also study tiny particles called exosomes that carry genetic material from tumors. The goal is to build a large database to improve future cancer care, but this study does not test a new treatment.