CA-125 vs. OVA1

What is CA-125?

CA-125 (cancer antigen 125) is a protein found in the blood and is frequently used as a biomarker for detecting the presence of ovarian cancer. It is elevated in certain types of ovarian cancer, but not others. A CA-125 test can be used to determine if a patient’s cancer has recurred and in some instances, to assess the risk of ovarian cancer before diagnosis.

Because the presence of ovarian cancer may coincide with elevated levels of CA-125, it has also been used historically to assess risk of malignancy before surgery, even though such use is not approved by the FDA. The test is not completely accurate as many noncancerous conditions can also result in increased levels of the protein. As a result, up to 50% of early stage cancers are not detected by CA-125.

What is the difference between CA-125 and OVA1?

OVA1, unlike CA-125, was cleared by FDA for the pre-surgical triage of ovarian cancer. OVA1 measures a panel of 5 biomarkers – including CA-125 – which sensitively detects malignancy across all stages and subtypes of ovarian cancer. As a result, fewer cancers are missed than CA-125 or other common methods. Because of the risk of ovarian cancer spreading to other areas, the high sensitivity of OVA1 in detecting a malignant risk becomes extremely important.


Early Stage Ovarian Cancer Detection by Sensitivity

Early Stage (stage I and II) Premenopausal Early Stage Postmenopausal Early Stage
66% 46% 75%
OVA1* 91% 91% 92%
      *Standalone; intended to be used with clinical assessment


    Bristow RE, et al., Gynecol Oncol. 2013;128:252-259