Most people are aware about CA125 by now. It is a blood test that measure our antibody responses to cancer antigen and it is called 125 because it was the 125th antibody against the studied ovarian cancer cell line. It is elevated in about 80% patients with advanced ovarian cancer as well in other cancers such as uterine, cervix and others. Unfortunately, it is also increases with other non-cancer conditions such as endometriosis, infection, inflammation, etc. Therefore, CA125 is FDA-indicated only to measure tumor responses to chemotherapy, not to screen for ovarian cancer.
Another relatively new biomarker is HE4 blood test. It is more specific than CA125 in that HE4 is not as elevated as CA125 in patients with endometriosis. HE4 is also only indicated for cancer monitoring, not as screening.
Ova1 is a blood test measuring 5 different proteins which is put into one score to help surgeons to triage patients as low or high risk for ovarian cancer. FDA cleared its usage for patients who are about to be operated for ovarian mass. If the Ova1 test is abnormal, the test would suggest that gyn oncologist should be involved in the surgery. In contrast, if the Ova1 test is normal, then the patient is at low risk for ovarian cancer and no gyn oncologist is needed to be involved. Disclaimer: West Clinic was involved in the clinical study leading to the FDA approval of this test.
ROMA is another blood test combining CA125 and HE4 into one score. ROMA is also FDA-cleared to be used like Ova1. Both Ova1 and ROMA are not indicated for ovarian cancer screening.
By now you may ask why don't any of these biomarkers be used to screen for ovarian cancer. Unfortunately, no present test is currently has enough sensitivity and specificity to screen for a low prevalence disease like ovarian cancer (prevalence is 1 out of 2500 American women = 0.04%). Even when we have a test with 100% sensitivity and 99% specificity, we only get about 4.8% of positive predictive value. This means that this ideal test will only identify correctly one patient with ovarian cancer but falsely diagnosed 20 other patients who have no cancer as having ovarian cancer. It is indeed a holly grail to find a better screening test.
Another relatively new biomarker is HE4 blood test. It is more specific than CA125 in that HE4 is not as elevated as CA125 in patients with endometriosis. HE4 is also only indicated for cancer monitoring, not as screening.
Ova1 is a blood test measuring 5 different proteins which is put into one score to help surgeons to triage patients as low or high risk for ovarian cancer. FDA cleared its usage for patients who are about to be operated for ovarian mass. If the Ova1 test is abnormal, the test would suggest that gyn oncologist should be involved in the surgery. In contrast, if the Ova1 test is normal, then the patient is at low risk for ovarian cancer and no gyn oncologist is needed to be involved. Disclaimer: West Clinic was involved in the clinical study leading to the FDA approval of this test.
ROMA is another blood test combining CA125 and HE4 into one score. ROMA is also FDA-cleared to be used like Ova1. Both Ova1 and ROMA are not indicated for ovarian cancer screening.
By now you may ask why don't any of these biomarkers be used to screen for ovarian cancer. Unfortunately, no present test is currently has enough sensitivity and specificity to screen for a low prevalence disease like ovarian cancer (prevalence is 1 out of 2500 American women = 0.04%). Even when we have a test with 100% sensitivity and 99% specificity, we only get about 4.8% of positive predictive value. This means that this ideal test will only identify correctly one patient with ovarian cancer but falsely diagnosed 20 other patients who have no cancer as having ovarian cancer. It is indeed a holly grail to find a better screening test.
Reference:
-Ueland, FR, et al. Obstet Gynecol 2011:VOL 117, NO. 6,
June 2011
-ROMA®
(HE4 EIA + Architect CA125 II™) Instructions For Use 2011-09, Fujirebio Diagnostics, Inc
-Bast RC, et al. Differential diagnosis of a pelvic mass. Int Gyn Cancer. 2012
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