The 2023 American Society for Clinical Oncology Annual Meeting featured several notable developments on the diagnostics side, including significant advances in multi-cancer early detection (MCED). Grail Inc. presented its results from SYMPLIFY, the first major study of its MCED test in symptomatic patients. The test showed a negative predictive value of more than 97% and a positive predictive value that exceeded 75% in individuals who presented to primary care with non-specific symptoms that prompted a referral for cancer evaluation.