ClinicalOmics: A single biomarker plus a fixed threshold may equal a missed
diagnosis—actually, a great many missed diagnoses. But fixed thresholds
aren’t inevitable. For example, a serum biomarker used to screen women
for ovarian cancer can yield more accurate results if it is assessed
serially. This biomarker, called cancer antigen 125 (CA125), can detect
cancer in 86% of women with invasive epithelial ovarian cancer
(iEOC)—provided the pattern of CA125 concentration changes over time is
assessed. If, however, CA125 figures in a simplistic “less than/greater
than” metric, screen-detected cancers are just 41% or 48%, according to
data from clinical trials or clinical practice, respectively.