Of the 250 749 patients with ovarian cancer diagnosed between 2004 and 2020 (median [IQR] age, 62.0 [52.0-73.0] years; 0.4% American Indian, 3.7% Asian, 8.6% Black, 85.2% White, and 2.0% other or unknown race and 6.7% Hispanic, 88.8% non-Hispanic, and 4.6% of unknown ethnicity), 212 477 had measured CA-125 levels, and 88.2% had an elevated CA-125 level at diagnosis. This evidence concerns the gene MUC16 and ovarian carcinoma.