BRCA Gene: What You Need To Know

Cancer is a disease caused when cells in a part of the body begin to divide and grow in an abnormal way. The disease is multifactorial and can be caused by both generic and non-generic factors. While most cancers are not usually inherited (passed down through families), some genetic factors can increase the risk of developing cancer, such as a previous family history of cancer or a certain type of genes- that if they are or become altered can increase or impact the risk of developing cancer.

Let us start with genes. Genes are what make up our DNA and carry the information that determines our characteristics and traits. In some people, these genes are altered and function in an abnormal way. This is known as a gene mutation, an altered gene, or a gene carrier.  Gene mutation can either be inherited or acquired due to lifestyle factors.

The most common type of inherited altered genes that increase breast cancer risk is the BRCA 1 gene ( Breast Cancer 1) and the BRCA 2 gene (Breast Cancer2). These genes are known as tumor suppressor genes and play a big role in preventing cancer by repairing DNA that can progress to cancer or the uncontrolled growth of tumors. It is important to note that having a gene mutation does not mean you will get breast cancer; moreover, due to these genes’ inability to produce the protein required to repair damaged cells, the risk of developing breast cancer is greater than those without the gene mutation. There are several other genes that can increase the risk of cancer; however, these genes are much less common and do not appear to increase the risk as much as BRCA1 and BRCA2 genes.

Cancer Recurrence and BRCA mutation

It is thought that women with either the BRCA1 or BRCA 2 gene mutation who overcome breast cancer with treatment are at increased risk of developing second cancer in the opposite breast.

It is estimated approximately  20%-30% of women will develop breast cancer in their opposite breast 10 years after their first cancer. While it is estimated that around 40%-50% will develop breast cancer in their opposite breast 20 years after their first cancer

It is estimated that approximately 1.2% of women in the general population will develop ovarian cancer sometime during their lives. However, women with the BRCA gene have an increased risk compared to the general population.

It is estimated roughly 39%–44% of women with the BRCA 1 gene will develop ovarian cancer by the age of 70-80 years of age.

While it is estimated roughly who inherit 11%–17% of women with the  BRCA2gene will develop ovarian cancer by 70–80 years of age.

The use of oral contraception in the general public has been seen to significantly reduce the risk of ovarian cancer, however, oral contraception can increase the risk of breast cancer. This is also true for women who carry the mutated BRCA gene.

BRCA and Ethnicity

The Prevalence of mutated BRCA 1 & 2 genes varies across specific population groups.

The prevalence in the general population is approximately 0.2%- 0.3%

The prevalence in the Ashkenazi Jewish population is around 2.0%. It is also thought the Ashkenazi Jewish population carries a harmful variant in one of these two genes. The harmful variant is often called founder mutations and is usually one of three specific variants.

The dutch, Icelandic, and Norwegian populations also commonly carry founder mutations. While the African American population is thought to have a BRCA1 variant which has not been seen in other population groups.

BRCA Testing

There are genetic tests available to see if someone has inherited a mutated BRCA 1or 2 gene or another variant. The test usually consists of a saliva sample or a blood test that analyses abnormalities in this gene. However, genetic testing is currently not available for the general population only those who are considered at risk.

You are considered as highly likely to have a mutated BRCA 1 & 2 gene or another harmful variant if:

• You have a family history of cancer particularly breast, ovarian, prostate, stomach, uterine, thyroid or colon.
• You have blood relatives diagnosed with breast cancer before the age of 50 years or have had cancer in both breasts or you have relatives diagnosed with triple cancer.
• You have a family member diagnosis with both ovarian and breast cancer
• You are of the Ashkenazi Jewish heritage.
• There is a known history of a mutated cancer gene in the family.

BRCA Prophylactic Treatment

f you have tested positive for a gene mutation, there are prophylactic options to lower the risk of having breast cancer. The type of prophylactic treatment depends on the type of mutated gene you carry.

The types of prophylactic treatment include:

Prophylactic mastectomy:

Also known as a preventative mastectomy or risk-reduction mastectomy. This is a surgical procedure to remove both breasts and has been found to reduce the risk of breast cancer by approximately 90%-95%. There are many options available to reconstruct the breast following this procedure. The options available usually include a breast implant, augtogolus reconstruction (using the body’s own tissues), or a combination of both. The reconstruction procedure can be done at the same time as the mastectomy, also known as immediate reconstruction, or months are even years later known as delayed reconstruction. For more information are round breast reconstruction click here.

Risk Reducing Drugs:

There are certain drugs that can be taken that have been found to reduce the risk of Oestrogen receptor-positive (ER) breast cancer, however, which drug you take will depend on whether you have been through menopause. The drugs are taken for approximately 5 years and have been found to reduce the risk of getting breast cancer by approximately 40-50%. However, these drugs are not suitable for women with BRCA 1 gene as this mutated gene does not generally get ER-positive cancer. The most commonly used drugs are:

• Tamoxifen (If you have not been throught the menopause) This medication is not suitable for women trying to get pregnant and is recommended to be used alongside contraception). This drug can also increase the risk of womb cancer and blood clots, however this is more common in women who have gone through the menopause.
• Anastrozole (for women who have gone through menopause).This drug can increase the risk of bone thinning and therefore is usually administered alongside other drugs to protect your bones.
• Raloxifene (for women who have gone through menopause).

These drugs may also cause side effects such as hot flushes, vaginal discharge, and dryness.

Cancer Screening

Some women who carry the mutated BRCA 1 & 2 gene decide not to opt for preventative surgery. For those women, regular cancer screening is generally recommended and can help detect breast cancer early.

Breast cancer screening: it is usually recommended to undertake breast screening (MRI or Mammography) every 6-12 months from the age of 25. However, regular screening could be undertaken earlier if a family member has been diagnosed with cancer under the age of 30.

Self Breast Examine: In addition to regular clinical breast screening, It is also recommended to undertake monthly self-breast examinations. Regular self-breast examinations can help you learn about your own breast tissue and what is normal for your breasts. This can help you detect any abnormal changes early.

Ovary Screening: it is usually recommended to start 6-12 month pelvic exams by a gynecologist between the ages of 30-35 years. The pelvic exams usually consist of a pelvic ultrasound with an intravaginal probe and a blood test to check for a special protein called CA-125.

Other Preventative Strategies

As with all cancers, and with women with and with gene mutations, certain lifestyle factors are known to increase the risk of developing cancer. Adopting healthy lifestyle choices can help you reduce your risk of developing cancer. This includes:

• Undertaking regular exercise

• Limiting alcohol intake

• Eating a health balanced diet filled with nutritious food.

• Limit or avoid alcohol and smoking.

• Maintaining a health weight.

Disclaimer
** The information presented here is not intended or implied to be a substitute for professional medical advice, diagnosis, or treatment. All content, and information, contained on or available through this website is for general information purposes only. 

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