Ovarian cancer tumor markers are proteins that cancer cells produce. Healthcare professionals can test tumor marker levels in a person’s bloodstream and use them alongside imaging and biopsy tests as part of the diagnostic process for ovarian cancer.

Ovarian cancer occurs when the cells in the ovaries begin to grow uncontrollably. This can form tumors within the ovaries, which prompts the body to create certain proteins called tumor markers.

Doctors use blood tests to check the levels of these proteins in a person with suspected ovarian cancer. However, not all individuals with ovarian cancer have high levels of tumor markers in their blood. Therefore, healthcare professionals need to use other diagnostic tools.

This article is about the types of ovarian cancer tumor markers and how doctors use them to test for ovarian cancer. It will also discuss ovarian cancer tumor types and symptoms.

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As a person’s cancer progresses, the cancerous cells may accumulate into masses of tissue called tumors.

Tumor markers are proteins that the body can produce in response to tumors. Doctors may test for certain tumor markers if they believe a person has ovarian cancer. They can use these tests alongside imaging screening techniques and tissue sampling.

However, it is important to note that elevated levels of all tumor markers, including carbohydrate antigen 19-9 (CA 19-9), can also occur in people with no ovarian cancer tumors.

Below are different types of ovarian cancer tumor marker tests.

CA-125

A 2022 review notes that cancer antigen 125 (CA-125) tests are the primary ovarian cancer tumor marker tests.

As the American Cancer Society (ACS) explains, this blood test looks for a protein called CA-125, which exists at elevated levels in most but not all people with ovarian cancer.

HE4

Human epididymis protein 4 (HE4) is another tumor marker. It often occurs in high quantities in tumors of the ovarian epithelial cells. These make up the outer layer of a person’s ovaries.

HE4 tumor markers are especially common with endometrioid ovarian cancer and have links to endometriosis and Lynch syndrome.

Scientists consider HE4 one of the best ovarian cancer tumor marker tests alongside CA-125, although they do not use it as commonly.

CA 19-9

CA 19-9 is another tumor marker. High levels of CA 19-9 have associations with some ovarian cancers, including clear cell cancers, teratomas, and secondary malignancies.

A 2020 study involving 314 people with a diagnosis of mucinous ovarian tumors evaluated the diagnostic performance of CA 19-19 and other tumor markers. Mucinous ovarian tumors are a rare form of ovarian cancer. The study found a significant association between high levels of CA 19-9 and borderline and cancerous mucinous tumors in patients.

Borderline tumors are not typically cancerous, as they feature more controlled growth. They are usually not able to spread, but they arise from the same type of cells as ovarian cancer.

CA 19-9 also has links to other cancers such as pancreatic cancer.

Germ cell tumor marker tests

Some ovarian cancers begin in the germ cells. Germs cells are those that can develop into gametes, also known as reproductive cells, such as sperm and eggs. When someone has germ cell ovarian cancer, their body can release certain tumor markers.

The ACS lists the following tumor markers as important examples:

Tumor cell marker algorithms

Doctors may ask laboratories to test a person’s blood for several different ovarian cancer tumor markers. Healthcare professionals can use algorithms that combine data from multiple tests to give more definitive results as part of the diagnostic process for ovarian cancer.

These algorithms include the risk of malignancy index and the risk of ovarian malignancy algorithm, the latter of which incorporates data from both CA-125 and HE4 tests.

As the ACS explains, ovarian cancer marker tests are a useful tool because the presence of elevated levels of tumor markers increases the probability that a person has cancer.

However, the ACS also notes that ovarian cancer tumor marker tests can be unreliable. This is because not everyone with the disease will produce elevated tumor marker levels.

Conversely, not everyone with elevated tumor marker levels has ovarian cancer. For this reason, these tests are not suitable for ovarian cancer screening, which is when doctors aim to detect presymptomatic ovarian cancer.

The unreliability of ovarian cancer tumor marker tests also means that doctors must use other tests for a reliable diagnosis.

One of these alternative tests is an imaging test, which can detect tumors and determine whether cancer has spread to other body parts. Examples of these imaging tests include:

Biopsies can serve as another test. Although imaging techniques can detect tumors, they cannot differentiate tumors from benign growths. Doctors must perform a biopsy after detecting growths around the ovaries with imaging tests. The biopsy will involve removing some of the growth before testing it for cancer cells in a laboratory.

As a 2021 study explains, some doctors also use cancer tumor marker tests to help determine the progression of someone’s cancer. This can help with treatment and give doctors a better impression of a person’s outlook.

Learn more about testing used for ovarian cancer.

Ovarian cancer can take several different forms. As the ACS explains, several different types of ovarian cancer tumors exist. These correspond to the three main types of cells that compose a person’s ovaries:

  • Epithelial tumors: Begin from epithelial cells, which cover the ovary’s outer surface. These tumors are the most common kind of ovarian cancer tumor. About 85–90% of cancerous ovarian tumors are epithelial cell tumors.
  • Stromal tumors: Begin in the ovary’s stromal cells and comprise about 1% of ovarian cancer tumors. Stromal cells create structural tissue, which holds the ovary together. They also function to produce hormones such as estrogen and progesterone.
  • Germ cell tumors: Begin in a person’s germ cells, which produce eggs. Less than 2% of ovarian cancer tumors are germ cell tumors.

Scientists also discuss two ovarian cancer subtypes: type 1 and type 2 tumors. The former tumors are slower growing and cause fewer health problems, while type 2 tumors tend to spread faster and are usually more advanced, which can lead to more fatal outcomes.

As a 2022 review explains, ovarian cancer presents with several different symptoms. Around 90% of people with early-stage ovarian cancer will have at least one of these symptoms. In those with late stage ovarian cancer, that figure is 100%.

Symptoms of ovarian cancer include:

Although these symptoms do not guarantee a person has ovarian cancer, anyone with symptoms should consult a healthcare professional.

Learn more about ovarian cancer symptoms.

Ovarian cancer is when the cells of the ovaries begin to grow uncontrollably. This disease can take several forms and may lead to various symptoms.

These symptoms can help doctors make a correct diagnosis, leading to an appropriate treatment plan.

Although ovarian cancer tumor markers are slightly useful to the diagnostic process, doctors must rely heavily on other techniques to make reliable diagnoses.