Which statement about CA125 testing is accurate?

• A. CA125 is not specific for ovarian cancers
• B. CA125 is highly specific for ovarian cancer
• C. CA125 is used only for screening men
• D. CA125 is a universal cancer marker

Answer: (A)

CA125 is a marker most often used to help manage ovarian cancer, but it is not specific to ovarian cancer. Levels can be elevated in many non-movarian conditions, such as endometriosis, pelvic inflammatory disease, liver or kidney disease, and even during menstruation or pregnancy. Because of these noncancer-related elevations, a high CA125 does not definitively indicate ovarian cancer, and a normal CA125 does not completely exclude it—especially in early-stage disease or certain tumor subtypes. This limited specificity is why CA125 is not used as a general screening test for ovarian cancer in the population, and it’s not a universal cancer marker. It remains most useful as part of a broader diagnostic workup and for monitoring treatment response or recurrence after therapy.