High levels of certain tumor markers in the blood can indicate the presence of ovarian cancer.
Also known as biomarkers, these substances can be measured using a blood test. But having a high level of one of these tumor markers doesn’t necessarily mean you have ovarian cancer.
Doctors don’t use tumor marker blood tests to screen people at average risk of ovarian cancer. But they are helpful in assessing ovarian cancer treatment and checking for disease progression or recurrence.
Read on to learn about various ovarian cancer tumor markers and how they’re used.
There are a number of different types of ovarian tumor marker tests. Each test looks for a different kind of biomarker.
Cancer antigen 125 (CA-125) is a protein and the most widely used ovarian cancer tumor marker. According to the Ovarian Cancer Research Alliance, over 80 percent of women with advanced ovarian cancer and 50 percent of those with earlier stage ovarian cancer have elevated amounts of CA-125 in their blood.
However, some benign, or noncancerous, conditions can also lead to elevated CA-125. These include:
Human epididymis protein 4 (HE4) is another tumor marker. It’s often overexpressed in epithelial ovarian cancer cells, which are cells in the outer layer of the ovary.
Small amounts of HE4 can also be found in the blood of people without ovarian cancer. This test may be used in conjunction with a CA-125 test.
Cancer antigen 19-9 (CA19-9) is elevated in several types of cancer, including pancreatic cancer. Less often, it’s due to ovarian cancer. It can also indicate a benign ovarian tumor or another benign disease.
You can also be healthy and still have small amounts of CA19-9 in your blood. This test isn’t typically used to look for ovarian cancer.
Several types of gastrointestinal and gynecological cancers are associated with high levels of cancer antigen 72-4 (CA72-4). But it’s not an effective tool for diagnosing ovarian cancer.
RMI stands for “risk of malignancy index.” It’s an algorithm that calculates a score using:
- CA-125 levels
- menopausal status
- features of a pelvic mass on ultrasound
The score indicates whether a person is at high or low risk of epithelial ovarian cancer.
Risk of ovarian malignancy algorithm, or ROMA, is another algorithm that combines:
- menopausal status
It’s used to assess whether an ovarian mass has a high or low likelihood of being cancerous.
A few other tumor markers can indicate the presence of germ cell ovarian cancer. Germ cell ovarian cancer occurs in the germ cells, which are the cells that become eggs. These markers include:
- alpha-fetoprotein (AFP)
- human chorionic gonadotropin (HCG)
- lactate dehydrogenase (LDH)
These tumor markers can also indicate other types of cancer or benign conditions.
On their own, tumor markers can’t confirm a diagnosis of ovarian cancer. Doctors use ovarian cancer tumor markers together with other tests to help make the diagnosis.
CA-125 is the most used tumor marker for ovarian cancer. But if your CA-125 level is typical, your doctor might test for HE4 or CA19-9.
If you have signs or symptoms of ovarian cancer, your doctor will likely start with a physical examination. Your personal and family medical history also play a role. Depending on these findings, the next steps may include:
- transvaginal ultrasound
- CT scan
- barium enema X-ray
- positron emission tomography (PET) scan
- surgery and biopsy to confirm or rule out cancer
After a diagnosis of ovarian cancer, tumor markers can help guide treatment. The tests can establish a baseline level of certain tumor markers. Periodic testing can reveal whether tumor marker levels are rising or falling. This indicates whether treatment is working or if the cancer is progressing.
These tests can also help monitor for recurrence, which is when your cancer comes back after treatment.
There are three main types of ovarian tumors:
- Epithelial tumors. These tumors are made up of cells from the outer layer of the ovary. According to the
American Cancer Society, most ovarian tumors are epithelial tumors. These tumors are typically diagnosed in women over age 50.
- Stromal tumors. Stromal tumors begin in structural tissue cells. These cells also produce sex hormones such as estrogen and progesterone. The Canadian Cancer Society says that stromal tumors make up about 7 percent of ovarian cancers. They’re usually found in women over age 50.
- Germ cell tumors. These tumors start in cells that produce eggs. They make up 2 to 3 percent of ovarian cancers. This type is more likely to occur in women in their teens and 20s.
Screening tests are used to detect cancer in people who don’t have symptoms. None of the available tumor marker tests are reliable enough to screen people at average risk of ovarian cancer.
For example, not everyone with ovarian cancer has elevated CA-125. According to the Ovarian Cancer Research Alliance, the CA-125 blood test can miss half of all cases. And there are several benign reasons for elevated CA-125.
A combination of CA-125 and HE4 might be helpful in screening people at high risk of ovarian cancer. But these tests don’t definitively diagnose ovarian cancer.
The U.S. Preventive Services Task Force (USPSTF) currently does not recommend routine screening by any method for people without symptoms or a higher risk of ovarian cancer. Researchers are searching for more accurate ways to screen for this condition.
Ovarian cancer tumor markers may be useful in screening people who are at high risk of ovarian cancer. But blood tests alone aren’t enough to make the diagnosis.
Ovarian cancer tumor markers can help assess the effectiveness of treatment and check for disease progression.
According to a 2019 review, in more than
That’s why it’s especially important to know the warning signs and report them to a doctor. If you believe you’re at a high risk of ovarian cancer, speak with a doctor about what tests might be appropriate for you and if there are ways to lower your risk.