Dr Heidi Peverill

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What are the BRCA genes and what should we all know about them?

BRCA1 and BRCA2 are genes that every single one of us have. We inherit one from each parent and their role is to make the proteins that repair our DNA. However, in very rare cases people inherit mutated variants of these genes which have been known to cause some types of cancers, most notably breast cancer and ovarian cancer. 

People that get the harmful genes can receive it from either parent. If a parent carries either the BRCA1 or BRCA2 gene, there is a 50% chance that their children will also have one of the genes. Unlike other forms of breast cancer, people who are diagnosed due to either of the BRCA genes, tend to develop breast cancer at an earlier age.

Approximately 13% of women will develop breast cancer during some point of their lives. However, for women that test positive for the BRCA gene mutation, it is much higher. According to the Brest Cancer Network Australia (BCNA), women with a BRCA1 gene mutation have a 72% chance of developing breast cancer and 69% for women with a BRCA2 gene mutation. 

What does it mean for the women that have it?

If you are found to have either BRCA1 or BRCA2 gene mutations, there are several options available to you to help reduce or manage the risk of breast cancer, including enhanced screening and risk-reducing surgery. 

Enhanced Screening  

It’s recommended that women without a BRCA gene mutation have second annual mammograms.  For women with the BRCA gene mutations, increased screening using mammogram, ultrasound and MRI is recommended, along with screenings at closer intervals. Women with the BRCA gene mutation should be referred to a specialist care team for coordination of their screening and monitoring.  

Medications

If you are at a high risk of breast cancer your doctor may recommend medications that will block the effect or production of estrogen in your body, which can promote the growth and development of breast cancer. Although effective in reducing the chance of being diagnosed with breast cancer, these medications have side-effects that you will need to discuss with your doctor. 

Risk-Reducing Surgery

If you are assessed as at a very high risk of developing breast cancer due to mutations of the BRCA genes, you may consider a preventative mastectomy, sometimes called a prophylactic mastectomy. 

There are two ways that this can be done. The first and most effective is a total mastectomy where both breasts are completely removed including the nipple. Or a subcutaneous mastectomy which preserves the nipple while removing as much of the breast tissue as possible. Important to note is that a subcutaneous mastectomy will give you a more natural look but the total mastectomy will provide the most breast cancer risk reduction of the two options. 

It is impossible for a surgery to completely remove all breast tissue susceptible to breast cancer. Small amounts generally remain around the chest wall, and sometimes around the armpit, collarbone, and even as low as the abdomen. With that being said, research suggests that getting a total mastectomy reduces the risk of breast cancer by at least 95% in women who have the mutation in the BRCA1 gene or the BRCA2 gene. Risk-reducing surgeries are lifesaving.

What happens after the breast tissue has been removed?

Depending on your preferences and anatomy, there are several options for breast reconstruction after a mastectomy. Surgical techniques can differ between surgeons so you should never feel uncomfortable or embarrassed asking your surgeon about their training or experience with each technique. It’s your body, and you will be the one living with the result, so ask as many questions as you need to feel comfortable. 

In most cases, women decide to have a breast reconstruction immediately after a preventative mastectomy. But if you feel that you are not immediately ready, you can choose to not have one, or postpone a breast reconstruction. This is called a delayed breast reconstruction and is an option if you change your mind. Important to note is that women that choose to have a mastectomy without breast reconstruction usually have their excess breast skin, areolas, and nipples removed, leaving the chest flat where the breasts were. When or if you choose to have a delayed breast reconstruction, you may need to have the skin around your breasts stretched to allow the new breast shape. 

If you want a breast reconstruction to occur at the same time as your mastectomy there are two main options available to you: an Implant Reconstruction (where the shape of the breast is rebuilt using implants), and a Tissue (Flap) Reconstruction (where the breast is rebuilt using skin, fat, and sometimes even muscle from another part of the body). Both options allow women to choose to preserve the skin over the breast, the areola, and the nipple. This typically results in breasts that visually seem closer to their before-surgery self. However, there will always be some scarring and differences to their shape and feel.


For many women, being diagnosed with a BRCA gene mutation can feel confronting and even terrifying at first. But my patients tell me how this knowledge about their body has also been empowering and lifechanging. Being able to take preventative steps following a BRCA mutation diagnosis can dramatically reduce the chance of getting breast cancer and support a person to live a healthy and breast cancer-free life.