Guardant Health, Inc. has initiated the Observation of ResiduAl Cancer with Liquid biopsy Evaluation (ORACLE) study, a 1,000-patient prospective, observational, multi-center study designed to evaluate the performance of its Guardant Reveal™ liquid biopsy test to predict cancer recurrence after curative intent treatment, across 11 solid tumor types. The Guardant Reveal test is the first blood-only liquid biopsy test that detects residual and recurrent disease from a simple blood draw. The test detects ctDNA in blood after surgery, to identify patients with residual disease who may benefit most from adjuvant therapy, and to detect recurrence months earlier than current standard-of-care methods.1-6 The commercially available test achieves high sensitivity (91%)7 for detecting ctDNA by simultaneously interrogating both genomic alterations and methylation. The first indication of the test is colorectal cancer, with additional cancer types to follow.