What Your Genes Say About Your Cancer Risk – Episode 43, To Your Health With Dr. Jim Morrow

What Your Genes Say About Your Cancer Risk – Episode 43, To Your Health With Dr. Jim Morrow

On this episode of “To Your Health,” Dr. Jim Morrow discusses what your genes say about your cancer risk, particularly breast cancer. He explains the genes found to impact chances of developing breast cancer as well as genetic testing. In addition, Dr. Morrow explains the difference between isolation and quarantine when it comes to Covid-19.  “To Your Health” is brought to you by Morrow Family Medicine, which brings the CARE back to healthcare.

Morrow Family Medicine is an award-winning, state-of-the-art family practice with offices in Cumming and Milton, Georgia. The practice combines healthcare information technology with old-fashioned care to provide the type of care that many are in search of today. Two physicians, three physician assistants and two nurse practitioners are supported by a knowledgeable and friendly staff to make your visit to Morrow Family Medicine one that will remind you of the way healthcare should be.  At Morrow Family Medicine, we like to say we are “bringing the care back to healthcare!”  Morrow Family Medicine has been named the “Best of Forsyth” in Family Medicine in all five years of the award, is a three-time consecutive winner of the “Best of North Atlanta” by readers of Appen Media, and the 2019 winner of “Best of Life” in North Fulton County.

Dr. Jim Morrow, Morrow Family Medicine, and Host of “To Your Health With Dr. Jim Morrow”

Dr. Jim Morrow is the founder and CEO of Morrow Family Medicine. He has been a trailblazer and evangelist in the area of healthcare information technology, was named Physician IT Leader of the Year by HIMSS, a HIMSS Davies Award Winner, the Cumming-Forsyth Chamber of Commerce Steve Bloom Award Winner as Entrepreneur of the Year and he received a Phoenix Award as Community Leader of the Year from the Metro Atlanta Chamber of Commerce.  He is married to Peggie Morrow and together they founded the Forsyth BYOT Benefit, a charity in Forsyth County to support students in need of technology and devices. They have two Goldendoodles, a gaggle of grandchildren and enjoy life on and around Lake Lanier.

Facebook: https://www.facebook.com/MorrowFamMed/

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The complete show archive of “To Your Health with Dr. Jim Morrow” addresses a wide range of health and wellness topics, and can be found at www.toyourhealthradio.com.

Dr. Morrow’s Show Notes

What Your Genes Say About Your Cancer Risk

• Virtually every human ailment has some basis in our genes.
  • Until recently, doctors were able to take the study of genes, or genetics, into consideration only in cases of birth defects and a limited set of other diseases.
  • These were conditions, such as sickle cell anemia,
    • which have very simple,
    • predictable inheritance patterns because each is caused by a change in a single gene.

• With the vast trove of data about human DNA generated by the Human Genome Project and other genomic research,
  • scientists and clinicians have more powerful tools to study the role that multiple genetic factors acting together and with the environment play in much more complex diseases.
  • These diseases, such as
    • cancer,
    • diabetes,
    • and cardiovascular disease constitute the majority of health problems in the United States.
  • Genome-based research is already enabling medical researchers to develop improved diagnostics,
    • more effective therapeutic strategies,
    • evidence-based approaches for demonstrating clinical efficacy,
    • and better decision-making tools for patients and providers.
  • Ultimately, it appears inevitable that treatments will be tailored to a patient’s particular genomic makeup.
    • Thus, the role of genetics in health care is starting to change profoundly and the first examples of the era of genomic medicine are upon us.

• It is important to realize, however,
  • that it often takes considerable
    • time,
    • effort,
    • and funding
      • to move discoveries from the scientific laboratory into the medical clinic.
    • Most new drugs based on genome-based research are estimated to be at least 10 to 15 years away,
    • though recent genome-driven efforts in lipid-lowering therapy have considerably shortened that interval.
  • According to biotechnology experts, it usually takes more than a decade for a company to conduct the kinds of clinical studies needed to receive approval from the Food and Drug Administration.

• Screening and diagnostic tests, however, are here.
  • Rapid progress is also being made in the emerging field of pharmacogenomics,
    • which involves using information about a patient’s genetic make-up to better tailor drug therapy to their individual needs.

• Clearly, genetics remains just one of several factors that contribute to people’s risk of developing most common diseases.
  • Diet,
  • lifestyle,
  • and environmental exposures also come into play for many conditions,
    • including many types of cancer.
    • Still, a deeper understanding of genetics will shed light on more than just hereditary risks
      • by revealing the basic components of cells and, ultimately,
        • explaining how all the various elements work together to affect the human body in both health and disease.

What Is A Gene?

• Each person’s DNA contains the code used to build the human body and keep it functioning.
  • Genes are the small sections of DNA that code for individual traits.
  • For example, someone with naturally red hair has a gene that causes his or her hair to be red.

• All inherited traits are passed down through genes.
  • Each person has two copies of every gene:
    • one gene from each parent.
    • Since each parent passes down exactly half of their genes to each child, any of the parent’s genetic traits has a 50% chance of being passed on to their offspring.

Screening for Hereditary Breast and Ovarian Cancers

• The goal of screening is to prevent cancer or to find the disease at an early stage, increasing the chance that it can be treated.

Screening Guidelines for Women at Average Breast Cancer Risk

• We recommend the following for women at average risk of breast cancer:
  • Women between the ages of 25 and 40 should have anannual clinical breast examination.
  • Women 40 and oldershould have an annual mammogram in addition to an annual clinical breast examination.
  • Ultrasound may be recommended for women with dense breast tissue.
  • All womenshould consider performing a monthly self breast exam beginning at age 20 and become familiar with their breasts so they are better able to notice changes.

What Is BRCA?

• The name “BRCA” is an abbreviation for “BReast CAncer gene.”
  • BRCA1 and BRCA2 are two different genes that have been found to impact a person’s chances of developing breast cancer.

• Every human has both the BRCA1 and BRCA2 genes.
  • Despite what their names might suggest,
    • BRCA genes do not cause breast cancer.
    • In fact, these genes normally play a big role in preventing breast cancer.
    • They help repair DNA breaks that can lead to cancerand the uncontrolled growth of tumors.
    • Because of this, the BRCA genes are known as tumor suppressor genes.

• However, in some people these tumor suppression genes do not work properly.
  • When a gene becomes altered or broken, it doesn’t function correctly.
    • This is called a gene mutation.

BRCA Mutations

• A small percentage of people
  • (about one in 400, or 0.25% of the population)
  • carry mutated BRCA1 or BRCA2 genes.
    • A BRCA mutation occurs when the DNA that makes up the gene becomes damaged in some way.

• When a BRCA gene is mutated,
  • it may no longer be effective at repairing broken DNA
    • and helping to prevent breast cancer.
    • Because of this, people with a BRCA gene mutation are more likely to develop breast cancer,
      • and more likely to develop cancer at a younger age.
      • The carrier of the mutated gene can also pass a gene mutation down to his or her offspring.

BRCA Mutation Risks

• It is estimated that one in eight women,
  • or approximately 12%,
  • will be diagnosed with breast cancer in her lifetime.

• However, women with certain genetic mutations have a higher lifetime risk of the disease.
  • It’s estimated that 55 – 65% of women with the BRCA1 mutation will develop breast cancer before age 70.

• Approximately 45% of women with a BRCA2 mutation will develop breast cancer by age 70.
• Women with a BRCA1 or BRCA2 mutation who overcome their breast cancer with treatmentappear to have a higher-than-average chance of developing a second cancer.
  • This is called a recurrence. Cancers related to a BRCA1 mutation are also more likely to be triple negative breast cancer, which can be more aggressive and difficult to treat.

• You may find these statistics alarming.
  • However, it’s important to note that less than 10% of women diagnosed with breast cancer have a BRCA mutation.
  • Also, with early detection, the vast majority of breast cancer cases can be successfully treated—and that’s true even for people who have a BRCA1 or BRCA2 mutation.

Who Should Be Tested For BRCA?

• While BRCA1 and BRCA2 gene mutationsmay increase your odds of developing breast cancer,
  • your odds of having either mutation are pretty small.
  • An estimated 0.25% of the general population carries a mutated BRCA gene,
    • or about one out of every 400 people.

• For some people, though, the chances of having a BRCA gene mutation are much higher.
  • Genes are inherited,
    • which is why knowing your family history is important when determining breast cancer risks.
    • If one of your parents has a BRCA mutation,
      • you have a 50% chance of inheriting the mutated gene.
    • Odds can also vary depending on a person’s ethnicity.
      • For example, people of Ashkenazi Jewish descent have a 2.5% chance of inheriting a BRCA mutation,
        • or about 10 times the rate of the general population.
      • Because the overall odds are so low,
        • most experts recommend that only people with a heightened risk get tested for BRCA mutations.
        • Likewise, insurance companies often only cover genetic counseling and testing for individuals who are at high risk.
        • A person could be considered at high risk for BRCA mutations if they have a family history of:
          • Breast cancer diagnosed before age 50.
          • Male breast cancer at any age.
          • Multiple relatives on the same side of the family with breast cancer.
          • Multiple breast cancers in the same woman.
          • Both breast and ovarian cancer in the same woman.
          • Ashkenazi Jewish heritage.

How To Get BRCA Genetic Testing

• Genetic counseling is recommended for those who are interested in being tested for breast cancer gene mutations.
  • You can talk to a doctor about getting a referral to a genetic counselor,
    • who can help determine whether genetic testing would make sense based on family history and risk factors.
    • Since many genetic tests only look for one specific gene mutation,
      • the counselor can often help determine which mutations to test for.
    • The genetic test itself simply involves taking a small sample of blood or saliva, which is sent to a lab for analysis.
      • Results can take several weeks or months.
    • Genetic testing results are not always clear-cut:
      • A test result can be positive, meaning that the patient does carry the gene mutation.
      • A negative test result indicates that they do not have that particular gene mutation.
        • It does not, however, rule out the possibility of having mutations in other genes.
        • It also does not rule out the possibility of developing breast cancer.
        • Most breast cancer cases are not hereditary,
          • so everyone should still have an early detection plan.
        • Genetic test results can also be uncertain or ambiguous.
          • An ambiguous test result means that a mutation has been found on the gene,
            • but it is not yet known whether that particular mutation has any effect on the chances of developing breast cancer.
          • After receiving genetic test results,
            • a patient should meet again with a genetic counselor to clarify what the results mean.
            • Whether the results are positive, negative, or ambiguous can impact many life decisions, and a counselor can help navigate those decisions.

What To Do If You’ve Tested Positive

• It’s natural to feel worried if you’ve tested positive for a gene mutation.
  • It’s true that these gene mutations can significantly increase your chances of developing breast cancer.
  • However, it’s important to keep in mind that many people who carry such gene mutations never develop breast cancer.
  • Even for those who do,
    • early diagnosisand treatment make it very likely that they will overcome the disease.
    • With early detection, the vast majority of people survive breast cancer and go on to live full, normal lives.

Early Detection Plans

• People with BRCA gene mutations have a higher-than-average chance of developing breast cancer,
  • and are more likely to develop it at a younger age.
  • Women with a BRCA1 or BRCA2 mutation can have a 45 – 65% chance of being diagnosed with breast cancer before age 70.
• The good news is that,
  • with this knowledge, you can create a custom early detection plan with your doctor to increase the chances that your breast cancer is detected early.
    • Early detection makes breast cancer far easier to treat.
    • Overall, the five-year relative survival rate for breast cancer detected in the localized stage
      • (there is no sign that the cancer has spread outside of the breast) is 99%.
    • An early detection plan for someone with a BRCA or PALB2 gene mutation will likely involve more frequent breast cancer screenings starting at a younger age.
      • It may also involve different types of screenings,
        • such as ultrasoundor MRI scans.
        • Your doctor can help recommend which screenings you should have, and when you should have them.

Preventative Surgery

• Though some consider it extreme,
  • women with high-risk BRCA mutations may choose to undergo preventative surgery to help reduce the risk of developing breast cancer.
• A preventative double mastectomy(or bilateral prophylactic mastectomy)
  • is the surgical removal of both breasts before cancer has a chance to develop and/or spread.
  • There are different types of preventative mastectomies;
    • some remove the entire breast,
    • while others leave the skin and nipples intact to aid in breast reconstruction surgery.
  • Actress and filmmaker Angelina Joliedrew public attention to using surgery to proactively address BRCA gene mutations when she publicly shared her story of undergoing a preventative double mastectomy.
    • She later chose to also have her ovaries and fallopian tubes removed, a procedure known as a preventative oophorectomy.
  • Though such preventative or prophylactic surgeries decrease the risk of developing breast cancer by about 90%,
    • they don’t eliminate the risk entirely.
    • Surgery itself also carries its own set of risks and costs,
    • which need to be carefully considered.
    • Your doctor can help you understand the options and risks and make the choice that is right for you.

BRCA And Breast Cancer Treatment

• If someone with a BRCA mutation does develop breast cancer,
  • the treatments used may be different than for people who do not carry the gene mutation.
• People with BRCA1 mutations are more likely to develop triple negative breast cancer.
  • Triple negative breast cancer does not respond to hormone therapy or certain drugs.
  • However, chemotherapy may be more effective at treating triple negative cases than it is against other types of cancer.
• Breast cancer patients with BRCA1 or BRCA2 mutations are also more likely to later develop a second cancer,
  • either in the same or the opposite breast.
  • Because of this, they may opt for a double mastectomy instead of a single or partial mastectomy.
  • Removing the healthy breast along with the cancerous one is essentially another form of a preventative mastectomy.
• Though research is still ongoing,
  • some findings indicate that certain types of cancer treatment drugs might be more effective than others in patients with BRCA gene mutations.
• As always, your doctor can help determine which breast cancer treatments are right for you.

Other Considerations

• There are many emotions and decisions that come along with a positive BRCA mutation test result.
  • Feelings can range from fear to anger, sadness, or guilt.
  • There can be questions about whether your children or other family members should be tested.
    • For some, it can affect the decision of whether or not to have children.
    • You may have concerns about passing on the mutated gene to your offspring;
      • some women even choose preventative surgeries that can make it difficult or impossible to have children.
    • Genetic counselors can help you navigate the waters and understand all the risks, decisions, and emotions involved.

What Your Genes Say About Your Cancer Risk