What Are Ovarian Cancer Blood Tests?

Ovarian cancer blood tests are diagnostic tests used to detect markers for cancer of the ovaries. These blood tests are used to detect the presence of substances that are often found in higher-than-normal levels in women who have ovarian cancer. Unfortunately, these tests are usually not reliable for the widespread testing of women who are not at high risk for the disease. Instead, they are often given to women who have a higher-than-normal risk for this type of cancer, are suspected of having the disease, or have been diagnosed with cancer of the ovaries in the past. By themselves, these tests are not considered reliable for diagnosing cancer, so other diagnostic procedures are used as well.

One type of ovarian cancer blood test is the cancer antigen 125 test, which is referred to as the CA 125 test. This test detects the elevation of a protein called CA 125 in the blood. Levels of this protein are often abnormally high in a woman who has ovarian cancer. This test is not foolproof, however, and can return higher-than-normal levels in a woman who does not have the disease. Unfortunately, both false negatives and false positives are possible with this blood test, so it is usually used in conjunction with other methods of diagnosing cancer of the ovaries.

The lysophosphatidic acid (LPA) test is also among the ovarian cancer blood tests that can be helpful for diagnosing patients with this life-threatening disease. This test looks for elevated levels of LPA in a patient's blood plasma. The majority of women who do have ovarian cancer also have elevated levels of this substance.

While ovarian cancer blood tests may prove helpful for diagnosing and monitoring ovarian cancer, there are many different tests and procedures that are used to provide a definite diagnosis. Among the tests a doctor may perform in an effort to provide an accurate diagnosis are ultrasounds, computerized tomography (CT) scans, and magnetic resonance imaging (MRI) scans. Doctors may also use pelvic exams and diagnostic surgeries to determine whether or not a patient has cancer. Positron emission tomography (PET) scans, which detect changes in blood supply, may prove helpful as well.

Ovarian cancer blood tests are often most useful for screening women who are at a higher risk of developing cancer of the ovaries. For example, a woman with a sister or mother who has ovarian cancer may be more likely to develop it, and ovarian cancer blood tests may help with earlier detection. Still, other testing is required even in these cases.