OVA1 vs. CA-125

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  OVA1 and CA-125?

OVA1 (MIA), unlike CA-125, was cleared by FDA for the pre-surgical assessment of ovarian cancer risk. 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 (MIA) in detecting a malignant risk becomes extremely important.

ProductEarly Stage (Stage I and II)Pre-menopausal Early StagePost-menopausal Early Stage
Early Stage Ovarian Cancer Detection by Sensitivity

What is the difference between OVA1 and ROMA?1,2,3

ROMA and OVA1 (MIA) have the same FDA intended use. Both tests are used to assess the cancer risk of adnexal masses prior to surgery and must be interpreted in conjunction with an independent clinical and radiological assessment and are not intended as a screening or stand-alone diagnostic assay. However, the performance of the two tests are different.

This can be demonstrated in a side-by-side view of individual validation studies and third party head-to-head comparisons.

ProductOv Ca Subtypes(n)PrevalenceSensitivitySpecificityPPVNPV
ROMA (Moore et al. 2011)All ovarian cancers47218.9%80.9%74.9%42.9%94.4%
OVA1 (Bristow et al. 2013)All ovarian cancers49418.6%92.4%53.5%31.3%96.8%

OVA1 (MIA) has robust data of early stage sensitivity with over 86 cancers evaluated.

Stage In/a-
Stage IIn/a-
Early Stage75%12
Moore et al., 2011 validation study
Stage I89%61
Stage II100%25
Early Stage92%86
Longoria et al., 2013

OVA1 (MIA) has strong evidence of high sensitivity across a broad range of subtypes. This is clearly characterized in non-epithelial ovarian cancers, LMPs, metastases and other malignancies.

Sensitivity (%)

100% 50% 0%
Epithelial Ovarian Cancer
Non-epithelial Ovarian Cancer
Metastic to ovary
Other malignancies

Head-to-head comparison study4

Grenache et al. 2015 evaluated both OVA1 (MIA) and ROMA in all samples which included 31 surgically confirmed malignancies in 146 adnexal masses. The results showed that OVA1 (MIA) had higher sensitivity, which allows optimal distribution of cancers to specialists and confidence in managing negative tests as they were more likely benign cases.


100% 50% 0%

Characterization of ROMA5

In Lennox et al.’s independent study, ROMA performed well for advanced ovarian cancer and high-grade serous histology by capturing 93% and 94% of these subtypes, respectively. However, a high false negative rate was observed for early stage cancers, pre-menopausal patients and other histological subtypes.

ROMACancers MissedSample Size (n)
Advanced Ovarian Cancer7%54
High-grade Serous Subtype6%58
Stage 146%35
Pre-menopausal Status27%30
Endometrioid Subtype35%18
Clear Cell Subtype30%11
View Sources
  1. Moore RG et al., Obstet Gynecol. 2011 Aug;118(2 Pt 1):280-8.
  2. Bristow RE, et al., Gynecol Oncol. 2013;128:252-259
  3. Longoria TC, et al., Am J Obstet Gynecol. 2014 Jan;210(1):78.e1-9
  4. Grenache DG, et al., Clin Chim Acta. 2015 Jan 1;438:358-63.
  5. Lennox GK et al., Int J Gynecol Cancer. 2015 Jun;25(5):809-14.
  6. American Congress of Obstetricians and Gynecologists, Practice Bulletin 174; 2016 Nov
Education for Providers

Understanding OVA1 Results

Learn about the terminology and performance measures to determine the accuracy of a diagnostic test.