Predictive Biomarker Tests for Ovarian Cancer: A Primer for Pathologists

Several biomarkers play a role in treatment selection for epithelial ovarian cancer. Homologous recombination deficiency (HRD) is a biomarker reflecting predisposing germline genetic changes as well as somatically acquired changes. Tumors with HRD may be eligible for poly-ADP(ribose) polymerase inhibitor therapy in the maintenance or recurrent setting. Expression of HER2 (ERBB2 gene product) or folate receptor alpha (FOLR1 gene product), assessed using immunohistochemical assays, is a biomarker for therapy with antibody-drug conjugates. Although the biomarker landscape in ovarian cancer remains relatively limited, these markers provide meaningful diagnostic and therapeutic guidance.