Understanding Hereditary Ovarian & Breast Cancer

Understanding Hereditary Ovarian & Breast Cancer

In the U.S., about 5 to 10 percent of people diagnosed with breast cancer have inherited an increased risk of developing the disease. In these cases, breast cancer runs in the family. Similarly, 5 to 10 percent of ovarian cancers diagnosed are hereditary.

A diagnosis of Hereditary Breast and Ovarian Cancer Syndrome (HBOC) is considered when there are multiple cases of breast cancer and/or ovarian cancer on the same side of the family. The chance that a family has HBOC increases in any of these situations:

  • 1 or more women are diagnosed at age 45 or younger
  • 1 or more women are diagnosed with breast cancer before age 50 with an additional family history of cancer, such as prostate cancer, melanoma, and pancreatic cancer
  • There are breast and/or ovarian cancers in multiple generations on the same side of the family, such as having both a grandmother and an aunt on the father’s side both diagnosed with these cancers
  • A woman is diagnosed with a second breast cancer in the same or the other breast or has both breast and ovarian cancer
  • A male relative is diagnosed with breast cancer
  • There is a history of breast cancer, ovarian cancer, prostate cancer, and/or pancreatic cancer on the same side of the family
  • Having Ashkenazi Jewish ancestry

BRCA1 & BRCA2 Gene Mutations

There are 2 primary genes linked with most families who have Hereditary Breast and Ovarian Cancer (HBOC): BRCA1 and BRCA2. BRCA stands for BReast CAncer. A “mutation,” or harmful genetic change, in either BRCA1 or BRCA2 gives a woman an increased lifetime risk of developing breast and ovarian cancers. Men with these gene mutations also have an increased risk of breast cancer and prostate cancer. There is a slight increase in the risk of other cancers including pancreatic cancer and melanoma among people with BRCA1 or BRCA2 mutations.

On average, women with an altered BRCA1 gene have a 50 to 85 percent risk of developing breast cancer by age 70. Their risk of developing ovarian cancer is 40 to 60 percent by age 85.

In women, the breast cancer risk associated with a BRCA2 mutation appear to be about the same as those for BRCA1 mutations — a 50 to 85 percent risk of developing the disease by the age of 70.For women with BRCA2 mutations the risk for developing ovarian cancer has been estimated to increase to 10% and 30% by age 70.

Mutations in BRCA1 and BRCA2 are about 10 times more common in those who are Ashkenazi Jewish than those in the general U.S. population.

If you are of Ashkenazi Jewish descent and either of the following are true, you should consider genetic counseling:

    • Any first-degree relative (mother, daughter, or sister) has been diagnosed with breast or ovarian cancer.
    • Two second-degree relatives (grandmother, aunt, or niece) on the same side of the family have been diagnosed with breast or ovarian cancer. These can be relatives on your mother’s or father’s side of the family.

I want to get tested for these mutations – where do I start?

Consider speaking with a genetic counselor

Genetic counselors work as members of a healthcare team, providing risk assessment, education and support to individuals and families at risk for, or diagnosed with, a variety of inherited conditions. Genetic counselors also interpret genetic testing, provide supportive counseling, and serve as patient advocates.

The National Society of Genetic Counselors website is a great place to start when searching for a genetic counselor. Health insurance typically pays for genetic counseling and in many cases pays for genetic testing when it is recommended by a doctor. However, it is important to check with your insurance company to verify coverage.

CLICK HERE for a Q&A interview that Tina’s Wish had with genetic counselor, Jessica Martineau from NYU Langone Medical, where she provides more helpful insights.