Multi-cancer early detection tests: Attributes for clinical implementation

Guideline-recommended screening programs exist for only a few single-cancer types, and these cancers represent less than one-half of all new cancer cases diagnosed each year in the U.S. In addition, these "single-cancer" standard of care (SoC) screening tests vary in accuracy, adherence, and effectiveness, though all are generally understood to lead to reductions in cancer-related mortality. Recent advances in high-throughput technologies and machine learning have facilitated the development of blood-based multi-cancer early detection (MCED) tests. The opportunity for early detection of multiple cancers with a single blood test holds promise in addressing the current unmet need in cancer screening. By complementing existing SoC screening, MCED tests have the potential to detect a wide range of cancers at earlier stages when patients are asymptomatic, enabling more effective treatment options and improved cancer outcomes. MCED tests are positioned to be utilized as a complementary screening tool to improve screening adherence at the population level, to broaden screening availability for individuals who are not adherent with SoC screening programs, as well as for those who may harbor cancers that do not have SoC testing available. Published work to date has primarily focused on test performance relating to sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV). MCED tests will require approval through the pre-market approval pathway from the United States Food and Drug Administration. Additional studies will be needed to demonstrate clinical utility (i.e., improvements in health outcomes) and establish optimal implementation strategies, (i.e., testing intervals), follow-up and logistics of shared decision making. Here, we propose core attributes of MCED testing for which clinical data are needed to ideally position MCED testing for widespread use in clinical practice.