Hereditary cancer

Hereditary breast cancer

What is Hereditary breast cancer?

Approximately 10 percent of patients with breast cancer have a genetic variant that increased their risk of developing the disease. An additional 20 percent have a close family member who also had breast cancer, suggesting a familial link even though no specific genetic variant was identified.

BRCA1 and BRCA2 are the most common genes known to increase the risk of breast and ovarian cancers. Variations in these genes can also increase the risk for other cancers, including fallopian tube cancer, primary peritoneal cancer, pancreatic cancer, melanoma, male breast cancer, and prostate cancer.

Some basic facts about Hereditary breast cancer

A genetic variation in BRCA1 or BRCA2 can increase the likelihood that a person will develop cancer in his or her lifetime.

Breast cancer Ovarian, fallopian tube & peritoneal cancer Pancreatic cancer Prostate cancer Melanoma
BRCA1 ♀: 40-87% ♀: 16-44%
BRCA2 ♀: 40-85% ♂: 7-8% ♀: 16-27% ♀: 2% ♂: 3% ♂: 20% ♀: Elevated ♂: Elevated

Many other genes can increase an individual’s risk of developing breast cancer, including CDH1, PALB2, PTEN, STK11, and TP53. Like BRCA1 and BRCA2, many of these genes also influence risk for other types of cancers.

Role of genetics in diagnosis

Genetic testing may be appropriate if you have:

  • breast cancer diagnosed before age 50
  • ovarian cancer at any age
  • male breast cancer at any age
  • bilateral breast cancer or two separate breast cancer diagnoses
  • triple-negative (ER/PR/HER2-neu negative) breast cancer
  • both breast and ovarian cancer in close relatives
  • breast cancer in two or more close relatives on the same side of your family
  • a close blood relative with cancer in both breasts
  • a known familial genetic variant in a breast cancer susceptibility gene
  • Ashkenazi Jewish heritage with a family history of breast cancer
  • a clustering of cancers that may suggest an inherited cancer syndrome, such as breast cancer, thyroid cancer, pancreatic cancer, prostate cancer, bone or soft tissue cancer, sarcoma, adrenocortical carcinoma, or leukemia/lymphoma—all on the same side of your family

Role of genetics in treatment

Knowledge of your inherited risk for cancer can be a useful tool to guide prevention and risk-reduction. If you have an elevated risk of developing cancer based on your genetic test result, you can work with your healthcare provider to create a plan designed to prevent a cancer entirely, or help to identify a cancer at its earliest, most treatable stage.

In addition, genetic testing produces information that may help you and your healthcare provider:

  • provide an explanation for your personal or family history of cancer
  • evaluate your risk of developing future cancers
  • make informed medical decisions, including treatment for an already-diagnosed cancer and/or surveillance and preventive options to help detect or prevent future cancers
  • qualify you for participation in clinical trials or research studies
  • identify other at-risk relatives for whom genetic testing is recommended

What can my family do with this information?

Identifying at-risk family members is one of the most important benefits of genetic testing. Screening family members for known familial genetic variants gives those who test positive the opportunity to make informed decisions on prevention strategies. For those who test negative, the results can bring peace of mind. Invitae offers a Family Variant Testing program; please inquire with your doctor.

How do I arrange for genetic testing?

Your physician will assist you in identifying and arranging for the appropriate genetic test(s). If you have specific questions or concerns about the testing, your physician may refer you to a genetic counselor to discuss further. Once you are ready to proceed with genetic testing, you will need to submit either a blood or saliva sample.