The Ultimate Guide to BRCA 1 and BRCA 2 - allbodies.

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The Ultimate Guide to BRCA 1 and BRCA 2

Thanks to Angelina Jolie, you’ve likely heard of the BRCA gene mutation (in case you missed it, it’s why she got that double mastectomy.) But what exactly is it and what happens if you have it? Read on...

WHAT IS A BRCA1 AND BRCA 2 MUTATION?

BRCA1 and BRCA2 (pronounced ‘braca’ or as an acronym, B R C A) are the names of two genes that everybody has – BRCA1 is found on chromosome 17, and BRCA2 is found in chromosome 13. They help to keep our bodies healthy by producing special proteins that repair damaged DNA in our cells, (1) and also function as tumor suppressors, limiting the growth and spread of tumors (#workingovertime).  Specific types of harmful mutations in these genes can make it harder for your cells to repair any DNA damage. It can also alter their tumor-suppressing abilities. Because of these limitations, such mutations can lead to an increased risk for certain kinds of cancers. (2)

 

In fact, these genes have been named BRCA because of their specific increased risk for breast cancer when mutated – BR (breast) + CA (cancer).

 

In addition, harmful BRCA1 and 2 mutations have been linked to an increased risk of ovarian and prostate cancer, as well as an increased likelihood to get these cancers earlier in life than the general population. (1)

 

It’s been estimated that half of all women* with breast cancer that also have a family history of the disease have a related genetic fault, including BRCA1, BRCA2 or TP53 (another gene with a similar function). (3) . About 1 out of 400 people in the general population carry a harmful BRCA1 or 2 mutation. (4)

IMPORTANT NOTE! Having the mutation doesn’t mean you will get cancer.  And, it is still possible to develop cancer even if you don’t have a mutation.

ARE ALL MUTATIONS TO THE GENE HARMFUL?

The short answer to this is, no. There are many possible mutations to these genes and we don’t’ yet know if all are harmful. (15)It’s important to remember that having the mutation doesn’t mean you will get cancer.  And, it is still possible to develop cancer even if you don’t have a mutation.

WHAT ARE SIGNS THAT I HAVE A HARMFUL MUTATION?

Some risk factors of harmful BRCA1 or 2 genetic mutations include:

 

  • Having multiple relatives on one side of the family with breast or ovarian cancer
  • Being diagnosed with breast cancer at a young age
  • Breast cancer in those AMAB (assigned male at birth) in your family
  • Being a member of a high-risk ethnic group:

 

People of Ashkenazi Jewish descent are much more likely to carry these – around 1 in 40 people of Ashkenazi Jewish descent are estimated to carry a harmful BRCA 1 or 2 mutation. (4) Other research has also found Norwegian, Dutch and Icelandic people to be more likely to carry certain harmful BRCA1 and 2 mutations. (1)

HOW DO I KNOW IF I ACTUALLY HAVE THE HARMFUL MUTATION?

Genetic testing (providing a DNA sample via blood or saliva) is the only way to know if you have a mutation.  

 

There are different types of genetic testing, ranging from targeted (looking for one specific type of mutation – in the case of known family history of mutation) to comprehensive (searching for all known harmful BRCA1 and 2 mutations). (1)

 

The procedure may be covered by your insurance, depending on your circumstances and risk level.

 

If you want to get tested but don’t qualify as high risk, you can alternatively seek out a private clinic. This can be very expensive – often ranging anywhere between $300 to $5000! (5) But, the FDA has recently authorized the genetic testing company 23andMe to test three common variants of the BRCA1 and 2 genes. (6) It’s important to note that the test does not detect all possible mutations, and thus should not be used alone in making a diagnosis.

 

Note: It’s also possible to receive an ambiguous or uncertain test result. For example, a genetic test could show that you have a mutation in BRCA1 or 2, but there hasn’t yet been enough research done to tell us whether or not it’s harmful.6 Because of this limited research, it’s also possible to receive a negative result, but still have a harmful BRCA1 or 2 mutation that we don’t even know exists yet, (1) causing it to be undetectable. Helpful, we know.

I TESTED POSITIVE FOR A MUTATION. DOES THIS MEAN I’M GETTING CANCER?

If you do test positive for a BRCA1 or 2 mutation, take a deep breath. We know it can be scary to receive this information, but just because you have a mutation, doesn’t mean you will get cancer. There are many other factors that come into play including your personal health history and current overall health status, stress, diet, lifestyle habits like smoking etc. We still don’t know exactly what leads one person with a BRCA mutation to go on to develop cancer, and not another.  

Here’s what receiving a positive test result does mean:

It does mean that your risk of getting breast and ovarian cancer is higher than it is for people who do not carry this mutation. Whether you have a mutation on BRCA1 or BRCA2 will have an influence on your risk. Here are some stats for ya, but remember, these do not take any of those aforementioned lifestyle and family history factors into account.

 

Around 12% of women* in the general population will develop breast cancer throughout their lifetime, which increases to 72% for women* with harmful BRCA1 mutations and 69% of women* with harmful BRCA2 mutations by the age of 80 years old.8 Those with harmful mutations are also more likely to have the cancer return and appear in the second breast. (8)

 

As far as ovarian cancer goes, in the general population, the lifetime risk of developing ovarian cancer is fairly low, at around 2%.2 Women* with  a harmful BRCA1 mutation have a 40-60% lifetime risk, and those with a harmful BRCA2 mutation have a 10-30% risk; for both groups this risk increases as women* enter their 40s. (2)

 

OK, not the most fun stats to read. But, remember, you are not a statistic. And a positive result for a gene mutation is not a cancer diagnosis. Age, your unique family history, lifestyle and even your own belief systems all play into the equation. It is important to look at your unique situation when talking to your care provider about next steps.

WHAT DO I DO W/ THE DIAGNOSIS? STAYING ON TOP OF A BRCA MUTATION…

Age plays an important role

Age as well as where you are in your reproductive life cycle has an impact on your overall risks, treatment and screening options. Some treatments are not recommended for those under 40 and some treatments are geared towards those who are postmenopausal. Keep reading!

Screenings

For people with harmful BRCA mutations, enhanced screening for breast cancer is usually recommended, including going more often and starting the screening process earlier. (1) Traditional Breast cancer screenings can include mammography (using x-rays to examine the breast); MRI (using magnetic and radio waves to gain an image of the inside of your body); or a mammogram-MRI combo. Others, like Dr. Christiane Northrup, MD, recommend investigating a less invasive testing method called Thermography, which looks at the amount of heat on the body’s surface.  Non-symmetrical heat patterns can indicate cancerous or precancerous tissues or other anomalies. This method may be particularly helpful for those with larger breasts and/or dense breast tissue. Which screening method is right for you (and likely to be most effective) depends on various factors (including your age), so your clinician will help you decide. Some research indicates that mammography may not be the best option for those under 30.

 

With regard to ovarian cancer, there is, unfortunately, no reliable screening method for detection at an early stage. (1)

Self Checks

You should regularly check your breasts/chest for any changes, new lumps or abnormalities (starting at the armpit!). For those who menstruate, the best time to check each month is 5-10 days after having your period2 as it’s easiest to detect lumps during this time since your breasts/chest are less likely to be swollen and tender.

Ask before sharing with your family

For those who do not have a family history of breast or ovarian cancer, but have received a positive result, it’s important to remember that not everyone wants to know about their genetic mutations. So, before sharing your results with family members that may also be affected, check in to see if they are interested in knowing this sort of information first.

WHAT CAN I DO TO REDUCE MY RISK OF DEVELOPING CANCER?

Research is still in the early stages of understanding the effect of lifestyle factors on the likelihood of cancer development for carriers of BRCA1 or 2 mutations, but here’s a rundown of what has been found so far:

Regular Exams

While it doesn’t reduce your risk of developing cancer, increased screenings can be helpful in catching any abnormalities earlier on.

Stop smoking cigs

Smoking cigs has been found to be associated with an increased risk of breast cancer in people carrying mutations of BRCA2. (9)

Staying Healthy Overall

Although we’re waiting for research to tell us more about the lifestyle changes we can make to reduce our risk, studies about the general population show that limiting alcohol consumption, maintaining a healthy weight, exercising and eating a balanced diet helps to reduce overall breast cancer risk. (2) These recommendations have already been incorporated into guidelines for risk management for people with BRCA1 or 2 mutations. (3) Dr. Christiane Northrup has some interesting suggestions here. 

Breastfeeding + Tubal Ligation

(AKA having your tubes tied) have been shown to reduce the risk of developing ovarian cancer (1) (9).

Oral Contraceptives

This one is kinda tricky as while they have been shown to reduce the risk of developing ovarian cancer, they have also been associated with a small increase in risk of developing breast cancer (2) as well other potential side effects. #Helpful. If you are interested in oral contraceptives or are currently on them and received a positive diagnosis, have a personalized conversation with your provider on this topic.

MORE AGGRESSIVE PREVENTATIVE OPTIONS

Surgical

There are some treatment approaches that help prevent cancer from occurring in the first place. Risk-reducing (or ‘prophylactic’, to be technical) surgery involves the removal of healthy tissue, which has a high chance of becoming cancerous later on. A ‘bilateral prophylactic mastectomy’, in which as much breast tissue as possible is surgically removed, can reduce your lifetime risk of breast cancer to around 5% – less than the risk of the average person without a BRCA1 or 2 mutation. (2)

 

A ‘bilateral prophylactic salpingo-oophorectomy’ (tongue-twisting medical speak for the removal of the ovaries and fallopian tubes) significantly reduces a BRCA1 or 2 mutation carrier’s risk of dying from ovarian cancer, to less than 5%. (2) Having this operation can also reduce the risk of being diagnosed with or dying from breast cancer. (7)

 

Surgery to remove the ovaries is not usually carried out on those under 40, due to the limited clinical benefit before this time. (2)

Medical

Some carriers are now turning to ‘chemoprevention’, which means the use of medication to reduce the risk of developing cancer. There is much more research needed on these, and some real risks and side effects involved. But it is a potential option. So, we’ll leave it there for now, but if it piques your interest, ask your provider!

EFFECT ON FERTILITY?

While having the gene mutation doesn’t make you less fertile, some treatment options may affect your fertility. So this is an important discussion to have with your provider depending upon your unique circumstances and future plans. It’s worth noting that the risk of ovarian cancer developing does not significantly increase for most people that carry BRCA faults until around 40 years old. (4) It’s possible to have children before this point and then have your ovaries removed, if this is the best option for you.

It is possible that your provider will recommend you investigate egg-freezing if you test positive for a mutation.  Do note that this DOES NOT mean you SHOULD freeze your eggs.  There are still many factors at play here and egg-freezing is not a procedure to be taken lightly.

EFFECT ON BIRTH?

Unfortunately, if you are a carrier of a BRCA1  or 2 mutation, there is a 50/50 chance that each child you have will also carry the gene and its associated health risks.

A myth floating around about BRCA1 and 2 mutations is that they can ‘skip’ generations. This is not true! Sometimes it looks this way because a carrier of the gene was male*– they are less likely than those who are female* to develop cancers as a result (although their risk is increased compared to other men* without these gene faults (2)).  Therefore, it could look as though there was no one of that generation carrying the harmful mutation since no one actually became unwell.

DOES THE GENE MUTATION MATTER FOR THOSE AMAB?

Yes – even though it’s rarer, it’s also possible for those assigned male at birth, to develop breast cancer. Although only about 1 in 1000 (0.001%) men* in the general population will develop breast cancer, for people with a BRCA2 mutation this risk rises to around 8% by the time they reach 80 years old.11 BRCA1 does also increase the risk of breast cancer, to around 0.1-1% (2).

 

But it’s not just breast cancer – unfortunately, the risk of prostate cancer is also raised. BRCA1 mutations raise the risk slightly, but BRCA2 mutations makes someone seven times more likely to develop prostate cancer. (11) The type of prostate cancer seen in carriers of BRCA mutations also tends to be more aggressive and occur at a younger age.

 

Although it’s currently unclear exactly how mutations of BRCA genes lead to a raised prostate cancer risk, some research suggests that sex hormones, including increased testosterone, may play a role 12 as might the mutations’ effect on androgens’ ability to limit tumor growth. (13)

 

Screening, treatment and lifestyle advice is similar for those with prostates; practice breast awareness, avoid unhealthy lifestyle factors, and engage in prostate screening procedures to reduce risk. (2)

 

Anyone who is at all concerned should arrange to see their healthcare provider to have an important conversation about their health now, and in the future.

Written by: Laura Hillier

Medically Reviewed by: Danielle LeBlanc, RN

All content found on this Website, including: text, images, audio, or other formats, was created for informational purposes only. The Content is not intended to be a substitute for professional medical advice, diagnosis, or treatment. Always seek the advice of your physician or other qualified health provider with any questions you may have regarding a medical condition. 

+ References

  1. National Cancer Institute (2018). BRCA mutations: Cancer risk and genetic testing. Retrieved from: https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet
  2. The Royal Marsden NHS Foundation Trust (2013). A beginner’s guide to BRCA1 and BRCA2.
  3. Breast Cancer Now (2019). Family history of breast cancer guide. Retrieved from: https://breastcancernow.org/about-breast-cancer/want-to-know-about-breast-cancer/what-can-cause-breast-cancer/family-history-of-breast-cancer-guide
    4. National Health Service (2018). Predictive genetic tests for cancer risk genes. Retrieved from: https://www.nhs.uk/conditions/predictive-genetic-tests-cancer/
  4. Breastcancer.org (2016). Genetic testing facilities and cost. Retrieved from: https://www.breastcancer.org/symptoms/testing/genetic/facility_cost  
  5. 23andMe (2019). Do you speak BRCA? Retrieved from: https://www.23andme.com/brca/
  6. Domcheck et al. (2010). Association of risk-reducing surgery in BRCA1 or BRCA2 mutation carriers with cancer risk and mortality. JAMA, 304(9), 967-75.
  7. Kuchenbaecker et al. (2017). Risks of breast, ovarian and contralateral breast cancer for BRCA1 and BRCA2 mutation carriers. JAMA, 317(23), 2402-2416.
  8. Friebel et al. (2014). Modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: A systematic review and meta-analysis. Journal of the National Cancer Institute, 106(1). Retrieved from: https://academic.oup.com/jnci/article/106/6/dju091/2606840
  9. Pollan et al. (2017). Effects of lifestyle and diet as modifiers of risk of breast cancer (BC) in BRCA1 and BRCA2 carriers. Journal of Clinical Oncology. Retrieved from: http://ascopubs.org/doi/abs/10.1200/JCO.2017.35.15_suppl.1505
  10. Breastcancer.org (2017). Men with BRCA mutations have much higher risk of cancer. Retrieved from: https://www.breastcancer.org/research-news/brca-mutations-up-cancer-risk-in-men
  11. Goldberg, Hanan, et al. “Is There a Difference in Testosterone Levels and Its Regulators in Men Carrying BRCA Mutations?” Oncotarget, vol. 8, no. 61, 2017, doi:10.18632/oncotarget.21802.
  12. Science Daily (2003). Male sex hormones cooperate with breast cancer genes to suppress tumors. Retrieved from: https://www.sciencedaily.com/releases/2003/06/030630111151.htm
  13. Cancer Research UK (2017). PARP inhibitors. Retrieved from: https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/targeted-cancer-drugs/types/PARP-inhibitors
  14. Domchek, Susan M., Greenberg, Roger A. “Breast cancer gene variants: separating the harmful from the harmless” Journal of Clinical Investigation. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2752087/
  1. National Cancer Institute (2018). BRCA mutations: Cancer risk and genetic testing. Retrieved from: https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet
  2. The Royal Marsden NHS Foundation Trust (2013). A beginner’s guide to BRCA1 and BRCA2.
  3. Breast Cancer Now (2019). Family history of breast cancer guide. Retrieved from: https://breastcancernow.org/about-breast-cancer/want-to-know-about-breast-cancer/what-can-cause-breast-cancer/family-history-of-breast-cancer-guide
    4. National Health Service (2018). Predictive genetic tests for cancer risk genes. Retrieved from: https://www.nhs.uk/conditions/predictive-genetic-tests-cancer/
  4. Breastcancer.org (2016). Genetic testing facilities and cost. Retrieved from: https://www.breastcancer.org/symptoms/testing/genetic/facility_cost  
  5. 23andMe (2019). Do you speak BRCA? Retrieved from: https://www.23andme.com/brca/
  6. Domcheck et al. (2010). Association of risk-reducing surgery in BRCA1 or BRCA2 mutation carriers with cancer risk and mortality. JAMA, 304(9), 967-75.
  7. Kuchenbaecker et al. (2017). Risks of breast, ovarian and contralateral breast cancer for BRCA1 and BRCA2 mutation carriers. JAMA, 317(23), 2402-2416.
  8. Friebel et al. (2014). Modifiers of cancer risk in BRCA1 and BRCA2 mutation carriers: A systematic review and meta-analysis. Journal of the National Cancer Institute, 106(1). Retrieved from: https://academic.oup.com/jnci/article/106/6/dju091/2606840
  9. Pollan et al. (2017). Effects of lifestyle and diet as modifiers of risk of breast cancer (BC) in BRCA1 and BRCA2 carriers. Journal of Clinical Oncology. Retrieved from: http://ascopubs.org/doi/abs/10.1200/JCO.2017.35.15_suppl.1505
  10. Breastcancer.org (2017). Men with BRCA mutations have much higher risk of cancer. Retrieved from: https://www.breastcancer.org/research-news/brca-mutations-up-cancer-risk-in-men
  11. Goldberg, Hanan, et al. “Is There a Difference in Testosterone Levels and Its Regulators in Men Carrying BRCA Mutations?” Oncotarget, vol. 8, no. 61, 2017, doi:10.18632/oncotarget.21802.
  12. Science Daily (2003). Male sex hormones cooperate with breast cancer genes to suppress tumors. Retrieved from: https://www.sciencedaily.com/releases/2003/06/030630111151.htm
  13. Cancer Research UK (2017). PARP inhibitors. Retrieved from: https://www.cancerresearchuk.org/about-cancer/cancer-in-general/treatment/targeted-cancer-drugs/types/PARP-inhibitors
  14. Domchek, Susan M., Greenberg, Roger A. “Breast cancer gene variants: separating the harmful from the harmless” Journal of Clinical Investigation. Retrieved from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2752087/

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