Ovarian cancer screening

Patient information: Ovarian cancer screening
Author
Karen J Carlson, MD
Section Editors
Suzanne W Fletcher, MD
Barbara Goff, MD
Deputy Editor
H Nancy Sokol, MD
Disclosures

INTRODUCTION — Ovarian cancer is one of the deadliest cancers in women, in part because it is often found at late stage. There is a great deal of interest in finding a test or combination of tests that could detect ovarian cancer at an early, treatable stage. However, studies have not yet shown that screening tests decrease the risk of dying of ovarian cancer. Until more studies are completed:

Women with no family history of ovarian cancer are advised to not have ovarian cancer screening unless enrolled in a clinical trial (file://clinicaltrials.gov).
Women with a “high-risk” family history of ovarian cancer are at increased risk of ovarian cancer. Women with a particularly high risk may benefit from ovarian cancer screening. (See ‘High risk family history’ below.)
This article will review the risks and benefits of screening for ovarian cancer. Diagnosis, staging, and treatment of ovarian cancer are discussed separately. (See “Patient information: Ovarian cancer diagnosis and staging” and “Patient information: Medical treatment of epithelial ovarian cancer”.)

More detailed information about ovarian cancer screening is available by subscription. (See “Screening for ovarian cancer”.)

AM I AT RISK FOR OVARIAN CANCER? — Factors that increase your risk of ovarian cancer include the following:

Older age
Having one or more relatives with ovarian cancer
Having abnormalities in a gene, called BRCA1 or BRCA2
Having genes that are linked to hereditary nonpolyposis colorectal cancer (also called Lynch syndrome)
Never being pregnant
Being overweight
Some factors can reduce your risk of developing ovarian cancer, including:

Using hormonal methods of birth control (pills, patch, vaginal ring, injection)
Being pregnant, breastfeeding
Having your tubes tied to prevent pregnancy
Having your uterus or ovaries removed
RISKS AND BENEFITS OF SCREENING — A screening test is one that can find a disease, such as cancer, in the early stages when there are no symptoms and when the cancer is most likely to respond to treatment. An example of a common screening test is the Pap smear, which is used to detect cervical precancers and cancers.

A screening test must find most people with the condition and not mistakenly find people who do not have the condition. A test that is positive when no disease is present is termed a “false positive” test. It is especially important to avoid having false positive tests for ovarian cancer, since a positive screening test usually requires surgery.

Benefits — The potential benefit of ovarian cancer screening is the chance to find the cancer at a curable stage, reducing the risk of dying.

Risks — The potential risk of ovarian cancer screening is a falsely positive screening test. This might lead to unnecessary surgery for many healthy women. Surgery carries risks of anxiety, injury, and time out of work, as well as a small risk of serious complications; it is also expensive.

SCREENING TESTS FOR HIGH RISK WOMEN — Studies are being done to find the best combination of screening tests for ovarian cancer. Tests that may be useful for women at high risk of ovarian cancer include a blood test of the CA 125 tumor marker, ultrasonography, or a combination of the two.

CA 125 tumor marker — CA 125 is a protein that is higher than normal in approximately 80 percent of women with ovarian cancer. It can be measured with a blood test. CA 125 is commonly used to monitor women with ovarian cancer.

It was hoped that CA 125 could be used to know if a woman was at risk for ovarian cancer. However, CA 125 levels can be high with a variety of other conditions, including:

Endometriosis
Uterine fibroids
Liver disease (cirrhosis)
Pelvic infections
Other cancers, including endometrial, breast, lung, and pancreatic cancer.
Also, CA 125 levels are higher than normal in about 1 percent of healthy women, and the levels change during the menstrual cycle.

So if you have a higher than normal CA 125 level, you could have ovarian cancer or a more common and less serious condition. Pelvic ultrasound may be helpful to know if you have ovarian cancer, although the only way to know for sure if you have ovarian cancer is to have surgery. As a result, CA 125 is not recommended as a stand-alone screening test for ovarian cancer.

Pelvic ultrasound — Pelvic ultrasound uses sound waves to create an image of the organs in the pelvis, including the ovaries. The test usually involves using an ultrasound wand on the abdomen and inside the vagina.

When used as a screening test for ovarian cancer, vaginal ultrasound can find between 80 and 100 percent of ovarian cancers. However, ultrasound cannot always tell the difference between ovarian cancer and other more common conditions (ovarian cyst, endometriosis). False positive ultrasound tests (abnormal tests that do not indicate) may lead to more testing or unnecessary surgery to further evaluate the ovary. As a result, pelvic ultrasound is not recommended as a stand-alone screening test for ovarian cancer.

Combined CA 125 and pelvic ultrasound — Several studies have looked at using CA 125 and pelvic ultrasound together to detect ovarian cancer. However, the results of these studies have been somewhat disappointing:

Many women had unnecessary surgery because of false positive test results (the CA 125 or pelvic ultrasound was abnormal but no cancer was found).
Some studies of CA 125 and pelvic ultrasound have found more cancers at an early, more treatable stage, while others have not. No published studies have shown that these tests reduce the risk of dying of ovarian cancer.
WHO SHOULD BE SCREENED?

High risk family history — A woman with a “high-risk” family history is someone who has a strong family history of breast or ovarian cancer in more than one relative or has family members with cancer who have certain characteristics.

Women with this history should meet with a genetic counselor to discuss genetic testing for BRCA1 and BRCA2 (table 1). Genetic testing is discussed in a separate article. (See “Patient information: Genetic testing for breast and ovarian cancer”.)

Ovarian cancer screening may be recommended if you have a high risk family history of ovarian cancer and:

You have a BRCA mutation and you have your ovaries
You have Lynch syndrome (also called hereditary nonpolyposis colorectal cancer [HNPCC]) and you have your ovaries
Ovarian cancer screening may also be considered for women who are eligible to have genetic testing (because of their high-risk family history) but who have chosen not to have genetic testing. In this group, ovarian cancer screening may be recommended, starting at age 30 to 35, or 5 to 10 years earlier than the age when the youngest family member was diagnosed. Screening may include a blood test for CA-125 and a pelvic ultrasound.

If you have a high risk family history, there are alternatives to ovarian cancer screening, such as having your ovaries removed to prevent cancer. These options are discussed separately. (See “Patient information: Genetic testing for breast and ovarian cancer”, section on ‘Interpreting the results’.)

Lower risk family history — Women who do not meet the criteria for a high-risk family history should discuss their risks for ovarian cancer with a healthcare provider. Ovarian cancer screening is not usually recommended for this group.

Average risk women — Women with an “average risk” of ovarian cancer do not have a personal or family history of ovarian cancer. Screening for ovarian cancer is not recommended in average risk women.

SYMPTOMS OF OVARIAN CANCER — During the early stages of ovarian cancer, symptoms are often vague and ill-defined. Symptoms may include pelvic or abdominal discomfort, bloating, difficulty eating or feeling full, increased abdominal size, or rushing to urinate frequently. However, these symptoms can also be caused by many other conditions.

If you have developed one or more of these symptoms in the past year, see your doctor or nurse. (See “Patient information: Ovarian cancer diagnosis and staging” and “Early detection of epithelial ovarian cancer: Role of symptom recognition”.)

WHERE TO GET MORE INFORMATION — Your healthcare provider is the best source of information for questions and concerns related to your medical problem.

 

Related topics for patients, as well as selected articles written for healthcare professionals, are also available. Some of the most relevant are listed below.

Patient Level Information:

Patient information: Ovarian cancer diagnosis and staging
Patient information: Medical treatment of epithelial ovarian cancer
Patient information: Genetic testing for breast and ovarian cancer

Professional Level Information:

Early detection of epithelial ovarian cancer: Role of symptom recognition
Genetic testing for hereditary breast and ovarian cancer syndrome
Management of hereditary breast and ovarian cancer syndrome and patients with BRCA mutations
Screening for ovarian cancer

The following organizations also provide reliable health information.

National Cancer Institute
(www.cancer.gov/cancertopics/pdq/screening/ovarian/patient/)

Medline Plus
(www.nlm.nih.gov/medlineplus/ency/article/000889.htm, available in Spanish)

REFERENCES
Rosenthal AN, Menon U, Jacobs IJ. Screening for ovarian cancer. Clin Obstet Gynecol 2006; 49:433.
Clarke-Pearson DL. Clinical practice. Screening for ovarian cancer. N Engl J Med 2009; 361:170.
Moore RG, MacLaughlan S, Bast RC Jr. Current state of biomarker development for clinical application in epithelial ovarian cancer. Gynecol Oncol 2010; 116:240.
Buys SS, Partridge E, Black A, et al. Effect of screening on ovarian cancer mortality: the Prostate, Lung, Colorectal and Ovarian (PLCO) Cancer Screening Randomized Controlled Trial. JAMA 2011; 305:2295.