Is Breast Cancer Hereditary?
Breast cancer is the most common type of cancer to be diagnosed around the globe, and the severity of the disease ranges widely. But with thirteen percent of U.S. cisgender women likely to develop breast cancer at some point in her life, it’s essential to spread awareness around the illness, how it can begin, and what sort of symptoms to look out for if you think you might be particularly susceptible. While many different risk factors can play into the possibility of developing breast cancer, genetic predisposition makes up about 5-10 percent of the nation’s cases. As a result, many people who have a known family history with the illness opt for a breast cancer DNA test – a.k.a., a test that will tell you the likelihood of you developing breast cancer at some point in your life.
What is breast cancer?
Like any form of cancer, breast cancer is the result of cells – in this case, breast cells – growing out of control. There are several different versions of breast cancer, depending on the part of the breast the irregular cell growth begins in. A breast is made up of five main parts:
- Lobules: the glands that produce milk
- Ducts: the tubes that carry the milk from the lobules to the nipples
- Connective tissue: the surrounding fatty matter that holds everything together
- Nipples: The opening in the breast’s skin where the ducts become larger so the milk can leave the breast.
- Blood and lymph vessels: Thin tubes that carry blood and lymphatic fluid throughout the breast.
Most types of breast cancer begin in the lobules or the ducts – but breast cancer can also spread outside of the breast and into other parts of the body, causing an even more damaging and lethal infection.
The different types of breast cancer
The type of breast cancer a person is diagnosed with – or thought to be more susceptible to based on a breast cancer DNA analysis – is determined by the type of cells that become cancerous. There are several recognized iterations of breast cancer, but in general, these are the most common:
- Ductal Carcinoma in Situ (DCIS)
DCIS is a non-invasive cancer where the affected cells are all located in the breast milk duct lining. It’s one of the most common forms of breast cancer – an early stage of the disease that is highly treatable. However, if time passes without treatment and DCIS continues to develop, it could spread into the surrounding breast tissue and morph into something more serious.
- Inflammatory Breast Cancer (IBC)
Inflammatory Breast Cancer is defined by cancer cells breaking into the breast’s skin and lymph vessels. It is aggressive, fast-growing, and incredibly difficult to detect, as it usually isn’t accompanied by noticeable tumors or lumps. Instead, IBC is recognized through a variety of other symptoms, like: persistent itching; rashes or irritation; red, swollen, warm breasts with enlarged pores; and flattening, dimpling, or inversion of the nipples.
- Invasive Ductal Carcinoma (IDC)
Making up about 80 percent of all cases, IDC is by far the most common type of diagnosed breast cancer. It’s also the most common type of breast cancer to affect men. With IDC, abnormal cancer cells form in the milk ducts and spread to other parts of the breast tissue – and the cells are also capable of spreading throughout the body.
- Invasive Lobular Cancer (ILC)
ILC begins in the lobules, spreading to surrounding tissue – and, in some cases, to other parts of the body. It’s the second most common type of breast cancer, and is difficult to detect with a mammogram or a breast cancer DNA test.
- Lobular Carcinoma in Situ (LCIS)
LCIS means abnormal cells are found in a person’s lobules. At this stage, the cancer cells have not spread to other parts of the breast. LCIS is highly treatable and rarely becomes invasive.
- Metastatic Breast Cancer
Also known as “Stage IV Breast Cancer” – which we’ll cover in the section below – Metastatic Breast Cancer means the cancer has spread to other parts of the body, like the liver, lungs, brain, or bones.
- Triple Negative Breast Cancer
Triple Negative Breast Cancer means the breast cancer cells have tested negative for the most common receptors that fuel breast cancer growth. Because the tumor cells lack these receptors, treatments like hormone therapy or other forms of medication are ineffective, but chemotherapy might still be a viable option.
Although the above types of breast cancer are definitely the most frequently-found, there are other recognized (although less common) iterations of the disease, like medullary carcinoma, mucinous carcinoma, tubular carcinoma, or Paget disease of the breast or nipple.
Cancer stages (and how they are determined)
The different types of breast cancer represent a range of stages, describing the size and progression of the tumor. Medical professionals will diagnose cancer with one of two systems: the number system, or the TNM system.
Number staging system
- Stage 0
This stage describes the cancer in situ – a.k.a., where it started, without having spread yet.
- Stage 1
At Stage 1, the cancer is still small and has not spread.
- Stage 2
At this stage, the cancer has grown, but still hasn’t spread.
- Stage 3
The cancer has grown more, and may have spread to surrounding tissue or lymph nodes.
- Stage 4
The cancer has spread to at least one other body organ.
TNM staging system
“T” describes the tumor’s size, followed by numbers 1-4 (1 being small, 4 being large).
“N” describes lymph nodes, followed by numbers 0-3 (0 meaning no lymph nodes have cancer, 3 meaning several lymph nodes have cancer).
“M” describes metastases – determining whether or not the cancer has spread to other parts of the body – followed by numbers 0-1 (0 meaning it has not spread, 1 meaning it has).
Is breast cancer hereditary?
As we mentioned earlier, about 5-10 breast cancer cases are deemed to be hereditary – which is why many people opt for a breast cancer DNA test or breast cancer DNA analysis if there’s a family history of the disease. So if you’re wondering to yourself, “Is breast cancer hereditary?”, it might be time to consult a breast cancer DNA analysis to check yourself for the BRCA genes. The BRCA genes (BRCA1 and BRCA2) are vital when it comes to fighting cancer. They’re tumor suppressors, and when they work in the average person, they help keep breast or ovarian cells from growing out of control. Any mutation or change in the BRCA genes can result in them not working normally, which means a person’s risk for ovarian, breast, or other types of cancers can go up. If you think you might be at risk of developing breast cancer, you may want to consult a breast cancer DNA analysis or breast cancer DNA test to check the status of your BRCA genes.
The main causes of breast cancer
When wondering, “Is breast cancer hereditary?”, the answer is: it definitely can be. However, there are other factors that might come into play when it comes to whether or not you’ll develop breast cancer. Other than hereditary genetics, here are some main breast cancer causes to keep in mind if you think you might be susceptible to eventual development.
- Getting older
In general, older people are more at risk for developing cancer – and the same is true for breast cancer. Most forms of breast cancer are diagnosed in people 50 years or older.
- Reproductive history
If you started your period before age 12 or began menopause after the age of 55, you’ve been exposed to hormones longer than the average cisgender woman – which, in turn, means you have a higher risk of developing breast cancer.
- Hormone therapy
Increased exposure to hormones may increase your risk of breast cancer – especially if the hormones were taken during menopause, and for five years or longer.
- Dense breasts
Dense breasts tend to have more connective tissue than fatty, which means tumors can be more difficult to detect and diagnose on a mammogram.
- Personal history of breast cancer or other breast diseases
People who’ve had breast cancer before are more likely to get it a second time. Likewise, having a history with other types of breast diseases might increase your risk of developing breast cancer.
- History with radiation therapy
Medical studies have revealed that if you’ve undergone radiation therapy in the chest area before the age of 30, you’re more likely to develop breast cancer later in life.
- Low physical activity
People with low physical activity levels are more likely to develop cancers and other types of life-threatening diseases, and breast cancer is no exception.
- Postmenopausal obesity
If you’re overweight or obese, you run a higher risk of developing breast cancer – especially if the excess weight accompanies you throughout menopause.
- Alcohol consumption
Medical studies have also revealed that people who consume alcohol regularly are more likely to suffer from breast cancer down the line – and the more alcohol consumed, the higher that risk will be.