Transient rise in CA 125 in a woman with ovarian carcinoma and COVID-19 infection.

Cancer antigen 125 (CA 125) is a transmembrane glycoprotein expressed on the surface of germinal epithelium and other tissues derived from embryonic coelomic epithelium (Bischof, 1993). CA 125 is a useful biomarker to detect treatment response and recurrence of ovarian malignancy (Montagnana et al., 2017), however, its use as a diagnostic marker is precluded by its limited specificity. CA 125 can be elevated in several non-ovarian malignancies including cervical, lung, and colorectal cancers (Johnson et al., 2008), and have also been found to be elevated in benign diseases involving coelomic epithelium, such as endometriosis, fibroids, ovarian cysts, and pelvic inflammatory disease (Sevinc et al., 2007). Recently, one retrospective study found that among all admitted patients with coronavirus disease 2019 (COVID-19) infection, increases in CA 125 and other cancer biomarkers were associated with severe COVID-19 infection (Wei et al., 2020). Thus, it is important for us to understand the potential impact COVID-19 has on CA 125 which may confound the treatment team of patients with gynecologic malignancy. Here, we report the case of a women with FIGO stage IVA ovarian high grade serous carcinoma (HGSC) during the COVID-19 pandemic who had a transient increase in CA 125 without evidence of progression of disease on imaging, and who was later found to have a positive COVID-19 antibody test.