Thresholds for Long-Recognized Ovarian Cancer Biomarker Leads to Treatment Disparities

The original study conducted on cancer antigen 125 (CA-125) in 1981 involved mostly White women as subjects, which established the thresholds applied universally to all women for early detection of ovarian cancer. A March 2025 study published in JAMA Network Open, however, concluded that the healthy levels of CA-125 in Black women were 10 to 37% lower, and for Native American women up to 20% lower, compared to White women. Consequently, these diverse populations have experienced delays in treatment and poorer health outcomes due to underdiagnosis based upon CA-125 test results.