© 2013 Rising Tide

Know Your Risk:

Understanding Genetics and Breast Cancer

Eric Fowler, MS, C/LGCCertified/Licensed Genetic CounselorCancer Treatment Centers of America®

© 2013 Rising Tide

Welcome & Introduction

Eric Fowler, MS, C/LGC

Certified/Licensed Genetic Counselor, Manager of Genetic Counseling

Cancer Treatment Centers of America®

© 2013 Rising Tide

Know Your Risk:

Understanding Genetics and Breast Cancer

Eric Fowler, MS, C/LGCCertified/Licensed Genetic CounselorCancer Treatment Centers of America®

© 2013 Rising Tide

Topics for Discussion

• Genetic Counseling• Factors Impacting Breast

Cancer Risks• Family History and Breast

Cancer Risks• General Genetics Information• Hereditary Breast Cancer• Genetic Testing• Case Example• Summary

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What is Genetic Counseling?

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Genetic Counseling - Definition

• Genetic counseling is the process of helping people understand and adapt to the medical, psychological and familial implications of genetic contributions to disease.

Source: National Society of Genetic Counselors, 2005

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Genetic Counseling - Process

• Interpretation of family and medical histories to assess the chance of disease occurrence or recurrence.

• Education about inheritance, testing, management, prevention, resources and research.

• Counseling to promote informed choices and adaptation to the risk or condition.

Source: National Society of Genetic Counselors, 2005

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What factors impact breast cancer risks?

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Breast Cancer

Risk

Family History

GenesEnvironment

Lifestyle

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Factors Impacting Breast Cancer Risks

• Age

• Family history

• Reproductive factors

• Hormone replacement therapy

• Benign breast disease

• Dietary factors

• Lifestyle

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Family History and Breast Cancer Risks

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Breast Cancer Risks Increase When:

• Closer relatives are diagnosed with breast cancer.

• Relatives are younger when diagnosed with breast cancer.

• Multiple relatives have breast cancer and or ovarian cancer.

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Impact of Family History on Breast Cancer Risks*

• Grandmother with breast cancer: risk increased by a factor of 1.27 times average risk.

• Mother, father or sister with breast cancer: risk increased by a factor of 1.73-1.8 times average risk.

• Two first-degree relatives with breast cancer: risk increased by a factor of 2.8 times average risk.

Study adjusted for age, age 1st period, region, socioeconomic status, number of children, and age at first birth*these risk comparisons are estimates and not applicable to any one person – other factors influence these risks, and risks are

underestimated if there is a hereditary cancer risk in a family

Bevier M et al. Breast Cancer Res Treat 2012 Apr;132(2):723-8

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General Genetics Information

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What is DNA?

• DNA, or deoxyribonucleic acid, is the genetic material in humans and almost all other organisms.

• DNA contains genetic instructions and is the blueprint for how our bodies develop, appear, and function.

Source: http://ghr.nlm.nih.gov/

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Chromosomes, DNA and Genes

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What are mutations?

• Mutations are alterations, or changes, in genes.

• Mutations in certain genes are associated with cancer.

• Mutations can be inherited from a parent (germline) or acquired (somatic) after conception.

Source: http://ghr.nlm.nih.gov

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Cancer Arises from Gene Mutations

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All cancer is genetic,butmost cancer is NOT inherited.

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Hereditary Breast Cancer

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How much breast and ovarian cancer is hereditary?

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Personal and Family History Clues that Increase the Chances of a BRCA Mutation

• Early-onset breast cancer (under age 50)

• Multiple relatives with early onset breast cancer

• Ovarian cancer (with family history of breast or ovarian cancer)

• Breast and ovarian cancer in the same woman

• Bilateral breast cancer

• Male breast cancer

• Ashkenazi Jewish heritage

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Hereditary Breast Ovarian Syndrome (HBOC)

• BRCA1 and BRCA2 – DNA repair genes• About 50% of hereditary breast cancer• About 90% of hereditary breast / ovarian cancer• Incidence is approximately 1/500 – 1/800 among those

of European, African and Asian descent• Incidence is 1/40 among Ashkenazi Jews (Jews of

Eastern European descent)

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BRCA1-Associated Cancers: Lifetime Risk

Increased risk of other cancers - pancreatic

Breast cancer 56%-85% (often early age at onset)

Second primary breast cancer 40%-65%

Ovarian cancer 30%-45% Male breast andprostate cancer

Adapted from ASCO Genetics Slide Set 2007

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BRCA2-Associated Cancers: Lifetime Risk

Increased risk of prostate, pancreatic cancers and possibly others

breast cancer (56%-85%)

ovarian cancer (10%-30%)

male breast cancer (6-8%)

Adapted from ASCO Genetics Slide Set 2007

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Clinical Management of BRCA1 and BRCA Mutation-Positive Patients

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Li Fraumeni Syndrome

• Caused by mutations in the p53 gene

• ~50% risk for breast cancer by age 60

• >90% risk for cancer by age 50 with childhood cancers observed

• Increased risks for cancers of the breast, brain, blood (leukemia), connective tissue (sarcoma) and others

• 5-7% of women with breast cancer at or under age 35 who test BRCA1/2 negative have p53 mutations

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Cowden Syndrome

• Caused by mutations in the PTEN gene

• Lifetime risk for breast cancer up to 85%

• Increased risks for cancers of the breast, thyroid, uterus, kidneys and others

• Includes non-malignant features such as larger head circumference, and benign growths in the breast, uterus, thyroid, mouth and skin

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Genetic Testing

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Genetic Testing Basics

• Genetic testing is usually performed on blood, saliva or mouthwash samples.

• Most insurance companies cover the cost of genetic testing if established criteria are met.

• Test results take 2-4 weeks up to 4 months to be reported.

• Results can be inconclusive – meaning a genetic alteration of unknown significance is found.

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Benefits of Genetic Testing

• Potential for a more accurate picture of cancer risk• Decision making

– Lifestyle – Chemoprevention– Cancer Screening– Surgery

• Help other family members

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Genetic Testing - Considerations

• Emotional reactions• Testing minors• Non-informative results• Confidentiality concerns• Fears of genetic discrimination

– HIPAA– GINA (Genetic Information Non-Discrimination Act)

• Does not eliminate other causes of cancer

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Case Example

• A 46 year-old women is diagnosed with a triple negative breast cancer in her left breast.

• Her paternal grandmother died of breast cancer at age 45.

• Her father was an only child, and she is also an only child.

• She stated she would change her breast cancer surgical decision-making if she has a BRCA1 or BRCA2 mutation.

• Her ovaries are intact.

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Case Example (continued)

• The patient postponed her breast surgery until after her test results were available.

• She tested positive for a BRCA1 mutation and decided to have bilateral mastectomies and has future plans to surgically remove her ovaries.

• Her 22 year old daughter’s genetic test results are pending.

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Summary

• Genetic counselors help patients understand and adapt to the implications of genetic diseases and make informed decisions about genetic testing.

• There are multiple risk factors for breast cancer.• All cancer is genetic, but most cancers do not happen

because of inherited reasons.• The likelihood of an inherited risk for breast cancer is

determined by an individual’s personal and family histories.

• Genetic test results impact medical management.• www.nsgc.org

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Thank you!

Eric Fowler, MS, C/LGC

Certified/Licensed Genetic Counselor

Cancer Treatment Centers of America