Patients and Caregivers

Ovarian Cancer


Ovarian cancer is the fifth most common cancer in women in the United States, accounting for 4% of all female cancers and 31% of cancers of the female genital organs. There are an estimated 22,000 new cases annually in the United States and each year more than 15,000 women will succumb to their illness. Women who are post menopausal are at the greatest risk for ovarian cancer.1 (American Cancer Society)

Ovarian cancer is a malignancy that forms in the tissues of the ovary and is caused by abnormal and uncontrolled cell growth. There are two types of ovarian cancer—epithelial and germ cell cancers. Epithelial makes up about 80 percent of the cases and forms from cells on the surface of the ovary. Germ cell cancers are caused by abnormal growth of egg cells. In their lifetime, 1 in 70 women will develop ovarian cancer.

CA 125™ is the current gold standard test for the management of ovarian cancer. It is used to monitor patients for recurrence and for response to therapy and treatment. CA 125 is a protein that is present in the majority of ovarian cancers. The protein is released by these cells into the blood stream and the concentration of the CA 125 protein can be measured with a simple blood test. CA 125 is elevated in about 80% of women with ovarian cancer, however not all elevations indicate a malignancy. CA 125 can be elevated in non-cancerous conditions such as menstruation, endometriosis, pregnancy, pelvic inflammatory disease, and benign ovarian cysts.

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Diagnosis of Ovarian Cancer

Ovarian cancer is a difficult cancer to diagnose, many of the symptoms are confounding and can be related to other illnesses (bloating, abdominal pain, frequent urination, etc.), thus delaying the diagnosis further. In some women a pelvic mass is identified which is then evaluated for an ovarian malignancy. There are approximately 250,000 women who present each year to their physician with an undiagnosed pelvic mass, 20% of which will be diagnosed, following evaluation, with malignant ovarian cancer. The CA 125 test is not recommended for use to diagnose patients with suspected ovarian cancer as there are other benign conditions that can affect the CA 125 value.

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Management of Ovarian Cancer

CA 125 has been used in the management of ovarian cancer for many years and its use in combination with other clinical results has enabled physicians to effectively manage patients with this disease. The CA 125 marker is used by physicians to determine a response to therapy in women who are undergoing chemotherapy and is also utilized in the early detection of recurrent disease.

Physician guidelines recommend monitoring and follow up with CA 125 at each visit if a patient had an initially elevated serum level during chemotherapy and following treatment. The CA 125 value is used to indicate a response to therapy based on the percentage decrease in the CA 125 value. In addition, the percentage increase of the CA 125 value or doubling from a baseline value indicates progression of disease.

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Frequently Asked Questions

What is the CA 125II tumor marker and how does it relate to ovarian cancer?

CA 125II is an antigen (tumor marker) frequently elevated in the serum of women with primary epithelial invasive ovarian cancer. However, not all women with ovarian cancer will have elevated CA 125II levels. CA 125II can also be elevated in patients with nonmalignant conditions, such as pericarditis, cirrhosis, severe hepatic necrosis, endometriosis (Stages II-IV), first trimester pregnancy, and ovarian cysts or in patients with non-ovarian malignancies, such as uterine carcinoma, hepatoma, pancreatic adenocarcinoma, and lung cancer.

Why is the CA 125II test performed?

The CA 125II test is performed periodically to aid in the detection of residual ovarian carcinoma in patients who have undergone first-line therapy and would be considered for diagnostic second-look procedures. Physicians and healthcare professionals may use serial CA 125II results to help determine the response of a tumor to therapy, to decide whether the treatment should be changed, or to determine if additional tests are necessary.

How is the CA 125II test performed?

A blood sample is taken from the patient and then sent to a laboratory for testing to determine the level of CA 125II present in the blood. The laboratory determines the amount of CA 125II present in the blood sample by using monoclonal antibodies known to specifically bind to CA 125II reactive determinants (antigens). By measuring the amount of bound antigen/antibody units, the laboratory can quantify the amount of CA 125II antigen present in the patient's blood sample.

What do the CA 125II test results mean?

Physicians use the CA 125II test results in conjunction with other diagnostic test results and full medical history to make decisions about the management of their patients. A physician typically requests a CA 125II test prior to the patient receiving treatment. This result serves as a baseline to compare with future measurements. During therapy, serial CA 125II results may be used to monitor response to therapy. Increasing results may be indicative of progressive disease, decreasing results may be indicative of response to therapy and constant results may be associated with stable disease.

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Use the following resources to learn more about Gynecologic Cancer:

  • Gynecologic Cancer Foundation - The mission of the GCF is to ensure public awareness of gynecologic cancer prevention, early diagnosis, and proper treatment. The GCF also supports research and training related to gynecologic cancers.
  • National Ovarian Cancer Coalition - The National Ovarian Cancer Coalition is the leading ovarian cancer public health information and education organization in the United States.
  • Ovarian Cancer National Alliance - Established in 1997, the Ovarian Cancer National Alliance is a coordinated national effort to place ovarian cancer education, policy, and research issues prominently on the agendas of national policy makers and women's healthcare leaders.

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  1. Ferlay, J, Bray, F, Psiani, P, Parkin, DM. Cancer Incidence, Mortality and Prevalence Worldwide IARC CancerBase No.5, version 2.0 Lyon, France: IARCH Press; 2004.