Ovarian cancer is often dubbed as the “silent killer” of women. The symptoms are vague—including bloating, fatigue, irregular bleeding, frequent urination, and back pain1 —making it difficult to diagnose early. By way of comparison, detection and treatment of breast cancer has progressed tremendously. This is demonstrated by the five-year relative survival rate, which is 90 percent for breast cancer and only 46 percent for ovarian cancer.2,3 Women may dislike the experience of mammography, but it remains an excellent screen for breast cancer. Unfortunately, there is not a similarly successful screen for ovarian cancer. In fact, the US Food and Drug Administration issued a safety watch advising women to be wary of tests that are marketed as ovarian cancer screens.4
The good news is only about 1 in 75 women will develop ovarian cancer in her lifetime—that’s a 1.3 percent risk. If we flip the number, there is a greater than 98 percent chance that a woman will not develop ovarian cancer in her lifetime. Your individual risk could be significantly higher, however, if you have a family history or a genetic predisposition.5
For example, women with Lynch syndrome have up to a 12 percent risk of ovarian cancer, and women with a BRCA1 or BRCA2 mutation have up to a 50 percent risk of ovarian cancer.6,7 You might recall actor Angelina Jolie talking about her decision to undergo preventive surgery to reduce her ovarian cancer risk.8 She did so because she inherited a BRCA1 mutation from her mother. Many women opt for similar preventive surgeries when they learn of an inherited high risk of ovarian cancer, but it’s important to know that there are also less invasive options, like taking birth control pills.7 The path is different for each woman, but having access to the information allows you to be proactive.
If you’re wondering whether DNA testing for ovarian cancer makes sense for you, your family history is a good place to start gathering information. If you notice that several family members have colon, uterine, or ovarian cancers, that could indicate Lynch syndrome; if you notice a family history of breast and ovarian cancers, that could suggest a BRCA1 or BRCA2 mutation. Keep in mind these are just clues; if you have a small family or there are not many women in it, a pattern may be hard to see. In fact, more than half the women9 with a genetic predisposition to ovarian cancer are the first women in their families to develop the cancer.
Women with a family history of ovarian cancer and those newly diagnosed with the disease often have questions about the role of hereditary risk. The reality is that most (90 percent) cases of ovarian cancer are sporadic, or not the result of an inherited genetic mutation; 10 percent are linked to hereditary syndromes. Answers to some common questions about hereditary risk and genetic testing.
Which hereditary cancer syndromes are associated with ovarian cancer?
Research has established two main hereditary cancer syndromes;
- Hereditary breast and ovarian cancer syndrome.
- Lynch syndrome
Knowledge of other, less common causes of hereditary ovarian cancer is continuing to expand the landscape of research in this field and we are continuing to learn so much that the answer is changing rapidly. Genetic testing has been advancing quickly, and we are continuing to discover new genes that are linked to an inherited risk for ovarian cancer.
Who should undergo genetic testing?
Women with any of the following risk factors should consider seeking genetic counseling to see if they are a candidate for testing:
- Women with a family history of breast or ovarian cancer
- Women diagnosed with an epithelial ovarian cancer at any age
- Women with a family history of breast, ovarian, colon, or endometrial cancer
- Women diagnosed with cancer at an early age (such as premenopausal breast cancer)
- Women with multiple cancer diagnoses
- Women with Ashkenazi Jewish ancestry
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When should women undergo genetic testing?
Ideally a woman should undergo genetic testing before she is diagnosed with cancer, though this special report: ovarian cancer is obviously not always possible. “The next best scenario is if genetic counseling and testing can occur before a patient undergoes surgery or other treatment,” she says. This is because if there is a chance to avoid additional surgery that might be recommended based on genetic testing results, surgical procedures could be combined to avoid risks associated with multiple surgeries. Results can also in some cases qualify an individual for a clinical trial adding to the incentive to test before treatment begins.
Why is genetic counseling important?
A genetic counselor plays a key role in helping patients and families understand the information that testing provides. For those who receive a positive result that shows they have inherited a specific hereditary syndrome counselors can provide individualized risk assessment plans for patients and their family members and coach them through screening protocols associated with their results and through sharing information with extended family. For those whose genetic-testing results are negative, meaning no genetic mutation has been identified a counselor will still carefully consider family history and may recommend earlier or more-frequent screening.
Hereditary Syndromes Related to Ovarian Cancer
Though new information about genes related to ovarian cancer risk is emerging, at this point there are two established hereditary syndromes linked with an increased risk of ovarian cancer.
- Hereditary breast and ovarian cancer syndrome is caused by mutations in the BRCA1 and BRCA2 genes. These genes act as tumor suppressor genes to protect women and men from certain cancers, such as breast, ovarian, melanoma, prostate, and pancreatic cancer. Women who have a BRCA1 or BRCA2 gene mutation have a 30 to 50 percent chance of developing ovarian cancer in their lifetime.
- Lynch syndrome is caused by an inherited genetic mutation in an individual’s mismatch repair genes, called MLH1, MSH2, MSH6, and PMS2. These genes are involved in fixing mistakes that occur during DNA replication. A person who has Lynch syndrome is at an increased risk of developing colon, endometrial (uterine), ovarian, stomach, small bowel, pancreatic, urinary tract, brain, and skin cancers. A woman who has Lynch syndrome has up to a 15 percent lifetime chance of developing ovarian cancer.
There are several women in my family who have had breast cancer and one who had ovarian cancer. How do I find out if I am at risk of developing ovarian cancer and whether I should have my ovaries removed prophylactically?
A. Most women who get ovarian cancer—90 percent in fact—have no known hereditary factors for developing the disease. The other 10 percent of diagnoses, however, are tied to hereditary factors, so being aware of your family history is certainly important. We’ve learned that there are at least two hereditary cancer syndromes linked to genetic mutations. The most common are the breast cancer gene mutations, referred to as BRCA1 and BRCA2. While women in the general population have a 2 percent chance of developing ovarian cancer by age 70, women with the BRCA1 mutation have an approximate 40 percent chance, and those with BRCA2 have a 10 percent chance.
Equally as common are genes related to Lynch syndrome, also known as hereditary non-polyposis colorectal cancer (HNPCC), which is associated with families in which members have had colon cancer, uterine cancer, or ovarian cancer at a young age. Women who inherit HNPCC-related genetic mutations have a 12 percent lifetime risk of ovarian cancer as well as increased risk of colon, stomach, and uterine cancers.
To fully understand your risk of ovarian cancer, it is important to conduct a formal risk assessment with a genetic counselor who is specially trained to provide information and advice about inherited conditions. The counseling should include analysis of your family tree, education about genetic-testing options, testing if appropriate, discussion of test results, and further counseling about risk-reducing options if you are found to be at high risk.
It is important to remember that even if you have a strong family history of ovarian cancer, you may test negative for the BRCA1/2 or Lynch syndrome mutations. If these mutations have been confirmed in your relative with ovarian cancer yet your test is negative, you did not inherit the gene that runs in your family and your risk is considered the same as that of women in the general population. If these mutations have not been confirmed in your family, however, you are still considered to be at higher risk of developing ovarian cancer than women in general, based on your family history.
If you are found to be at increased risk of ovarian cancer, your doctor may recommend prophylactic oophorectomy, or removal of the ovaries and the fallopian tubes. Expert organizations such as the National Cancer Institute traditionally recommend that high-risk women consider this surgery by age 35 or after childbearing is completed. They qualify this recommendation, however, by stressing that the decision should be made on a case-by-case basis. Women consider this surgery because ovarian cancer is a serious disease that tends to be diagnosed at a later stage after it has spread beyond the ovaries, which makes it difficult to cure. Also, because the ovaries are located deep in the body, early-stage tumors are difficult to detect through physical examination or imaging. Women also find that surgery is a way to take control of an anxiety-producing situation.
Prophylactic oophorectomy is not without side effects, particularly for premenopausal women. For this reason some women opt not to have surgery or to delay it. For women who are premenopausal, the surgery can cause sudden rather than gradual symptoms of menopause, including hot flashes, vaginal dryness, and reduced libido. The absence of ovaries and the reduced estrogen may also cause such symptoms as insomnia, muscle pain, and mood swings as well as a long-term risk of osteoporosis and cardiovascular disease. Many of these symptoms can be addressed with exercise, medication, and other interventions.
In the face of this choice, some premenopausal women choose a “wait and watch” strategy, with regular pelvic ultrasounds and CA-125 blood tests. If you choose risk-reducing surgery, you may want to consider a gynecologic oncologist trained in surgery and oncology because occasionally women are found to have ovarian cancer at the time of the surgery, and the surgeon can convert the prophylactic surgery to a therapeutic surgery.Decision-making about risk-reducing surgery is a complex process, and what feels right for one woman may not be right for another. Consult with family members, physicians, genetic counselors, and support organizations. Take the time you need to have your questions answered and become comfortable in your plan.
- What Are the Signs & Symptoms of Ovarian Cancer? National Ovarian Cancer Coalition website. Available at: . Accessed January 14, 2017.
- Cancer Stat Facts: Female Breast Cancer. National Cancer Institute website. Available at: . Accessed January 14, 2017.
- Cancer Stat Facts: Ovarian Cancer. National Cancer Institute website. Available at: . Accessed January 14, 2017.
- Ovarian Cancer Screening Tests: Safety Communication—FDA Recommends against Use. US Food and Drug Administration website. Available at: . Accessed January 14, 2017.
- NOCC Delivers Hard Hitting Message for September National Ovarian Cancer Month. National Ovarian Cancer Coalition website. Available at: . Accessed January 14, 2017.
- Lynch Syndrome. Cancer.Net website. Available at: . Accessed January 14, 2017.
- Hereditary Breast and Ovarian Cancer. Cancer.Net website. Available at: . Accessed January 14, 2017.
- Pitt AJ. Angelina Jolie Pitt: Diary of a Surgery. New York Times. March 24, 2015. Available at: . Accessed January 14, 2017.
- Finch A, Bacopulos S, Rosen B, et al. Preventing ovarian cancer through genetic testing: A population-based study. Clinical Genetics. 2014;86(5):496-99. doi: 10.1111/cge.12313.