Navigating Complexity: Perspectives on Risk Assessment in the Era of New Blood-Based Tests for Early Cancer Detection.

In recent years, there has been a surge in the development of new, blood-based, single- and multi-cancer detection tests (SCD and MCD), which can detect cancer signals prior to the onset of symptoms or clinical diagnosis of cancer. Recognizing the need for consensus definitions and standardized evidence development frameworks for these new types of blood tests, the Early Detection and Screening Working Group of the Blood Profiling Atlas in Cancer Consortium, a collaborative initiative dedicated to advancing standards and best practices, developed and published a lexicon for liquid biopsy-based SCD and MCD tests. During the preparation of the lexicon, the group recognized challenges with regard to the definitions of key terms and concepts describing absolute and RR assessment of intended use populations for cancer screening tests. This article captures the working group's discussions on (i) risk assessment including considerations for adapting historical SCD risk terminology like "average risk" and "elevated risk" to MCD tests, (ii) the implications of this terminology for describing intended use populations, and (iii) the existing gaps in evidence for determination of absolute risks.