By Kelli Conlan, MS; Genomic Science Liaison, Genomic Services & Meghan Wayne, MS: Genomic Science Specialist, Genomic Services

September 17, 2019 Better Health

September is Ovarian Cancer Awareness Month:
Genetic testing is an essential part of care for women with ovarian cancer and their families.
1 in 78 women will be diagnosed with ovarian cancer in their lifetime.1 In 2019, there will be an estimated 22,530 women diagnosed with ovarian cancer in the United States.1 While ovarian cancer isn’t the most common cancer, a significant percentage of women are diagnosed at a later stage when the cancer is more difficult to treat. This is at least in part because the symptoms of ovarian cancer are often overlooked or explained away.

Ovarian cancer symptoms
· Vaginal bleeding (particularly if post-menopause), or vaginal discharge that is not typical
· Pain or pressure in the pelvic area
· Abdominal or back pain
· Bloating
· Feeling full too quickly, or difficulty eating
· A change in bathroom habits, such as more frequent or urgent need to urinate and/or constipationWomen are encouraged to consult their healthcare provider if they experience any of these symptoms, particularly for two weeks or more.

Ovarian cancer risk factors
Some factors that can increase a woman’s chance of developing ovarian cancer are older age, having children later or never having a full-term pregnancy, and having a family history of ovarian cancer.2

Genetic tests can help identify those at even higher risk
10-20% of ovarian cancer is due to a hereditary predisposition. There are a number of genes that are associated with a hereditary predisposition to ovarian cancer. Individuals with cancer-causing variants in these genes can have a significantly increased risk of ovarian cancer compared to the general population. The most well-known genes linked to hereditary ovarian cancer are BRCA1 and BRCA2 which also increase the risk for breast, prostate, and other cancers. With BRCA, the risk of ovarian cancer can be as much as 44%.3,4,5 The genes associated with hereditary non-polyposis colorectal cancer or Lynch syndrome (MLH1, MSH2, MSH6, PMS2, and EPCAM) also increase the risk for ovarian cancer, endometrial, and other cancers. Studies have also identified a number of additional genes involved in hereditary ovarian cancer, such as BRIP1, RAD51C, and RAD51D. Genetic testing is available for these genes.

Different types of genetic testing: germline and somatic
There are different types of genetic tests for ovarian cancer. Germline testing, which is what most people are familiar with, is used to check for cancer-causing variants that are present at birth and can be passed on in families. Most often, germline testing is performed using blood or saliva samples. The results may tell a person whether or not they have a hereditary predisposition to cancer and can predict future cancer risks. An example is testing a person’s blood sample for a BRCA1 or BRCA2 variant.
Somatic testing is used to check for variants that are only in a person’s cancer. Somatic testing for ovarian cancer is performed by testing a piece of a person’s ovarian tumor. The results can be used in many ways, including identifying targeted therapies and predicting response to treatment. Scientists are now realizing that both germline and somatic tests are very important in the care of women who have been diagnosed with ovarian cancer.

Universal genetic testing for ovarian cancer
Published guidelines by the National Comprehensive Cancer Network® (NCCN) support hereditary genetic testing for all women diagnosed with ovarian, fallopian tube, and primary peritoneal cancer. Somatic testing is recommended for women who have ovarian cancer depending on their stage and their prior treatment history.6
Individuals who have not had ovarian cancer but have a family history of ovarian or other cancers that could be associated with a hereditary risk should talk with a healthcare provider about genetic testing.

PARP inhibitors
PARP inhibitors are a specific kind of FDA-approved therapy for women with ovarian cancer and who have either a germline or a somatic variant in BRCA1 or BRCA2.7 Other FDA-approved therapies or clinical trials may also be available based on the results of a woman’s genetic test results. For more information about somatic testing currently performed at Quest, please visit www.questdiagnostics.com/Watson.

Learn more about genetic testing for ovarian cancer
Visit www.questvantage.com and take the “Know Your Risk” quiz to see if genetic testing might be right for you. Our genomic science specialists are also available to help with test selection and interpretation. Healthcare providers can call 1.866.GENE.INFO.

References:

  1. American Cancer Society website. Cancer Facts & Figures 2019. org. Accessed August 20, 2019.
  2. American Cancer Society website. org. Accessed August 9, 2019.
  3. Antoniou A, Pharoah PDP, Narod S, et al. Average risks of breast and ovarian cancer associated with BRCA1 or BRCA2 mutations detected in case series unselected for family history: a combined analysis of 22 studies. Am J Hum Genet. 2003;72:1117-1130. DOI: 10.1086/375033.
  4. Chen S, Parmigiani G. Meta-analysis of BRCA1 and BRCA2 penetrance. J Clin Oncol. 2007;25:1329-1333. DOI: 10.1200/JCO.2006.09.1066.
  5. Kuchenbaecker KB, Hopper JL, et al. Risks of Breast, Ovarian, and Contralateral Breast Cancer for BRCA1 and BRCA2 Mutation Carriers. JAMA. 2017 Jun 20;317(23):2402-2416. DOI: 10.1001/jama.2017.7112.
  6. National Comprehensive Cancer Network website. org. Accessed August 15, 2019.
  7. US Food & Drug Administration website. gov. Accessed August 20, 2019.