Hereditary Cancer Screening

Hereditary cancers, including breast, ovarian, colon, and pancreatic cancer

What is Cancer?

Cancer is class of disease where there is uncontrolled growth of abnormal cells in the body.

Cancer develops when the body’s normal process of cell growth goes wrong and new cells form when the body doesn’t need them and old or damaged cells do not die as they should.

Buildups of these abnormal cells often invade healthy cells and may form a mass of tissue, called a lump, growth or tumor.

What is Hereditary Breast and Ovarian Cancer (HBOC) Syndrome?

HBOC syndrome is an inherited genetic condition.  This means that the cancer risk is passed from generation to generation in a family.

If you have HBOC syndrome, you carry a gene mutation you inherited from your father or your mother, or sometimes from both parents, that significantly increases your risk for certain cancers.

Hereditary Breast and Ovarian Cancer (HBOC) syndrome can be inherited from either the father’s side or the mother’s side of the family.

What Causes HBOC?

BRCA1 and BRCA2 (BReast CAncer genes 1 and 2) are the most well-known genes linked to breast cancer risk and are associated with the majority of HBOC families.

BRCA1/2 mutations can be passed to you from either parent and can affect the risk of cancers in both women and men.

Inherited mutations of either the BRCA1 or the BRCA2 gene causes about 10% of breast and ovarian cancers.

Other, less common genes have also been associated with an increased risk of developing breast and other cancers, such as mutations in the TP53, PTEN, CDH1, ATM, CHEK2 or PALB2 tumor suppression genes.  The BRCA1 and BRCA2 genes normally help regulate cell growth.  A person who has a BRCA1/2 mutation is sometimes called a BRCA1/2 carrier.

A mutation or alteration in either BRCA1 or BRCA2 increases a woman’s lifetime risk of developing breast and ovarian cancers.

A person with BRCA1/2 mutations not only has a higher risk of developing these cancers, but also may pass that gene mutation on to his or her children.

Men with these gene mutations also have an increased risk of breast cancer and prostate cancer.

Not all families with multiple cases of breast and ovarian cancer have mutations in BRCA1 or BRCA2.

How Common is Hereditary Breast and Ovarian Cancer?

Like other gene mutations, BRCA1/2 mutations are rare in the general population.  Women in the general population have about an 8% chance of getting breast cancer by age 70 and about a 12% chance by age 85.

This means in a group of 100 women without a mutation, about eight women will get breast cancer by age 70 and about twelve women by age 85.

Current estimates are that less than 1% of the general population has a BRCA1/2 mutation.

Women who have a BRCA1/2 gene mutation have an increased risk of breast cancer.  About 10-15% of women diagnosed with breast cancer have a BRCA1/2 mutation.

  • BRCA1 carriers have a 55 to 65% chance of developing breast cancer by age 70.
  • BRCA2 carriers have about a 45% chance of developing breast cancer by age 70.

This means in a group of 100 women with a BRCA1/2 mutation, between 45 and 65 will get breast cancer by age 70.  These numbers represent average risk, so the risk of breast cancer for any one woman with a BRCA1/2 mutation may fall outside this range.

BRCA1/2 mutation is present in 10-30% of women under age 60 diagnosed with triple negative breast cancer.

Together, BRCA1/2 mutations are thought to explain a large portion of hereditary breast cancers. Most breast and ovarian cancers, however, are not hereditary.

BRCA1 and BRCA2 Gene Mutations and Ethnicity

Among Ashkenazi Jewish women and men, about 1 in 40 have a BRCA1/2 mutation.
Approximately 1 in 10 women with breast cancer and 1 in 3 women with ovarian cancer in Ashkenazi families have BRCA1/2 mutations.

The table below shows how the prevalence of BRCA1/2 mutations varies among breast cancer survivors from different ethnic groups in alphabetical order.

 

Ethnicity BRCA1 BRCA2
African-American 1% 3%
Ashkenazi Jewish 8-10% 1%
Asian-American Less than 1% Data not available
Caucasian (non-Ashkenazi Jewish) 2-3% 2%
Hispanic 4% Data not available

 

BRCA1/2 Mutations and Ovarian Cancer

BRCA1/2 mutations increase a woman’s risk of ovarian cancer.

For women in the general population, the lifetime risk of ovarian cancer is less than 2%.

However, for women with the BRCA1 mutation, lifetime risk of ovarian cancer up to age 70 is 35 to 70%.

For women with the BRCA2 mutation, this risk is 10 to 30%.

Factors That Increase Inherited Risk for Cancer

Many people are unaware of their inherited risk, though they may be aware of a cancer history in their family.  You should consider talking with a doctor about genetic testing for hereditary breast and ovarian cancer (HBOC) syndrome if at least one of the following applies to you or your family:

  • Breast cancer before age 50
  • One or more relatives diagnosed at age 45 or younger
  • Two or more relatives who’ve had breast cancer
  • A male relative who’s had breast cancer
  • Breast cancer in both breasts or twice in the same breast
  • Being in a family Ashkenazi or Eastern European Jewish ancestry
  • Ovarian cancer at any age
  • A family member with a BRCA1/2 mutation or mutations in other related breast cancer risk genes
  • A history of breast cancer, ovarian cancer, prostate and/or pancreatic cancer on the same side of the family

BRCA1/2 Mutations and Cancer in Men

Men can also have BRCA1/2 mutations and may pass them on to their children.

Breast Cancer

Men who have a BRCA2 mutation have an increased risk of breast cancer.

In women 5 to 10% of breast cancers are considered to be due to gene mutations. However, in men up to 40% of breast cancers may be related to BRCA2 mutations. This means that men who get breast cancer are more likely to have an inherited gene mutation than women who get breast cancer.

In men, the lifetime risk of breast cancer is 1 in 1,000 for non-carriers and about 65 in 1,000 for BRCA2 carriers.

Men who have a BRCA1 mutation may also have an increased risk of breast cancer, but this link is less clear.

Prostate Cancer

Men who have a BRCA2 mutation may also have an increased risk of prostate cancer.

For BRCA2 carriers, the lifetime risk of prostate cancer up to age 65 is about 15 to 20%.

Cancer Risks for Women with BRCA1/2 Mutation

Lifetime risk of breast cancer: 50% to 85%

Risk of breast cancer before age 50: 30% to 50%

Lifetime risk of ovarian cancer:

  • BRCA1 gene mutation: 25% to 50%
  • BRCA2 gene mutation: 15% to 30%

Developing a second breast cancer: 40% to 60%. The risk of breast cancer occurring in the other breast rises approximately 2% to 3% per year.

Cancer Risks for Men with BRCA1/2 Mutation

Lifetime Risk of Breast Cancer

  • BRCA1 gene mutation: 1% to 2%. This is a 10-fold increase over the general population.
  • BRCA2 gene mutation: 6%

Risk of Prostate Cancer

  • BRCA1 gene mutation: some increased risk
  • BRCA2 gene mutation: 20%

Men with a BRCA2 gene mutation have a significantly increased risk of developing more aggressive prostate cancer before age 65 and therefore screening should begin at age 40.

Screening For BRCA1/2 Gene Mutations

The BRCA gene test is most often a blood test. Your blood sample is collected in your doctor’s office and sent to a laboratory for DNA analysis. Saliva sample can also be used for the analysis.

It takes several weeks before test results are available. Your doctor or genetic counselor will contact you with your test results, discuss their implications and go over your options. Federal and state laws help ensure the privacy of your genetic information and protect against discrimination in health insurance and employment.

From a BRCA screening test, you learn whether you carry an inherited BRCA gene mutation and receive an estimate of your personal risk of breast cancer and ovarian cancer.

Risks and Benefits of BRCA Screening

The medical risks from having blood drawn for a genetic test are very small and are associated with having your blood drawn such as lightheadedness, bleeding or bruising.

Test results however, may have an effect on your emotions, social relationships, finances, and medical choices.

If you test positive for a BRCA gene mutation, you may feel anxious, depressed, or angry.  You will have to make difficult decisions about whether or not to take steps to lessen your risk of developing breast or ovarian cancer and about what follow up care is right for you.  You may also have feelings of “inevitability” that you’ll get cancer.

If you test negative for having a BRCA gene mutation, you may experience survivor guilt caused by the knowledge that you likely do not have an increased risk of developing a disease that may have affected your loved ones.

Because there are instances when a test result may be ambiguous, meaning that you have a genetic mutation which has not been associated with cancer in other people, you may feel uncertainty and concern that your result may not be a true negative result.

What Do The Test Results Mean?

Testing does not tell you if you currently have cancer. Your test results tell you about your inherited risk of having breast and ovarian cancer.

A negative test result means that you do not have a BRCA1 or BRCA2 gene mutation.

Although the BRCA gene test can detect the majority of mutations in the BRCA1 and BRCA2 genes:

  • You could have a gene mutation that the test wasn’t able to detect.
  • Or if your family carries a high-risk gene mutation that researchers haven’t yet identified then the test would not be able to detect this gene mutation and you could be a carrier.

A negative test result doesn’t eliminate the chance of developing a non-hereditary breast cancer. You still have the same cancer risk as that of the general population.

A positive test result means that you have a BRCA1 or BRCA2 gene mutation. A positive test result does not mean that you have cancer or that you will have cancer. Having the BRCA1/2 mutations does not mean that you will get breast cancer. Many women with a BRCA1/2 mutation will never have breast cancer.

A positive test result tells you that you a much higher risk of developing breast cancer or ovarian cancer compared with someone who doesn’t have the mutation. A positive test result helps you to better understand your personal risk of developing breast and ovarian cancers. You can then make choices on what to do to reduce your risk and about what follow up care is right for you.

Follow-up Care After a Positive Test Result

You might choose to take specific measures to reduce your cancer risk. What you choose to do depends on many factors, including your age, medical history, prior treatments, past surgeries and personal preferences.

To reduce your cancer risk after a positive test result, you might:

Increase Screening: Having clinical breast exams every six months and mammograms and magnetic resonance imaging (MRI) exams every year.

Use Oral Contraceptives: Oral contraceptive use has been shown to reduce ovarian cancer risk in BRCA mutation carriers. However, your risk of breast cancer goes up slightly if you use oral contraceptives for more than five years.

Chemoprevention: Take a medication to reduce your risk of cancer.

Undergo Preventive Surgery Such As:

Preventive (Prophylactic) Mastectomy: For persons with the BRCA gene mutations, removal of healthy breast tissue reduces breast cancer risk by about 90%.

Preventive Salpingo-Oophorectomy: In premenopausal women, removal of healthy fallopian tubes and ovaries reduces breast cancer risk by as much as 50%. In both pre and postmenopausal women, it also reduces ovarian cancer risk by as much as 90%.

Preventive surgery does not eliminate all cancer risk. It is possible for cancer to develop in any tissue that couldn’t be removed through surgery.

Patient Advocacy Groups

Please see the hyperlinks below to learn more.

For Patient Videos and FAQs, please visit our Knowledge Portal.


force

Facing Our Risk of Cancer Empowered

http://www.facingourrisk.org/index.php


we-can

Women’s Empowerment Cancer Advocacy Network

http://www.womenscanceradvocacy.net/en.html


susan-g-komen

Susan Komen

http://ww5.komen.org/

 


alamo-bcf

Alamo Breast Cancer Foundation

http://www.alamobreastcancer.org/resources/



men-against-cancer

Men Against Breast Cancer

http://www.menagainstbreastcancer.org/



mbcn

Metastatic Breast Cancer Network

http://mbcn.org/



mbcc

The Male Breast Cancer Coalition

http://malebreastcancercoalition.org/



ysc

Young Survival Coalition

https://www.youngsurvival.org/



acs

American Cancer Society

http://www.cancer.org/


nih

National Cancer Institute

http://www.cancer.gov/


cancer-support

Cancer Support Community

http://www.cancersupportcommunity.org/


living-beyond

Living Beyond Breast Cancer

http://www.lbbc.org/


nocc

National Ovarian Cancer Coalition

http://www.ovarian.org/


abcd

After Breast Cancer Diagnosis

http://www.afterbreastcancerdiagnosis.com/


acos

Breast Cancer Advocacy Organizations