Are Relatives of Someone with Breast Cancer Automatically at Risk?

It is only natural to be concerned as to whether there is an increased risk of cancer in your family if you or one of your close family members (mother, father, brother, sister, son, or daughter) have been diagnosed with breast cancer. This is known as a family history of cancer. However, most breast cancers are not associated with family history or family genes. In fact, most women who develop breast cancer do not have a family history of the disease. Only in a small number of cases does breast cancer run in the family. Around 15% of women have a significant family history of breast cancer and 1 in 20 inherit a specific gene linked with the disease.

What Are Breast Cancer Genes?

Our bodies’ cells contain thousands and thousands of genes, which we inherit from our parents. If you have a significant family history of breast cancer, then this is due to inherited faults known as breast cancer genes. The most common breast cancer genes are known as BRCA1 and BRCA2. In such instances, your risk of developing breast cancer is higher than the general population.

A few other risk factors associated with hereditary breast cancer include the following:

• If a 1st degree relative has been diagnosed with breast cancer.
• If three 1st degree or 2nd degree relatives on the same side of the family have been diagnosed with breast cancer before the age of 60.
• If two relatives have been diagnosed with breast cancer, both on the same side of the family and one of them is a first-degree relative.
• If you have one relative with breast cancer and one relative with ovarian cancer on the same side of the family.
• If you have a 1st degree male relative in your family that has been diagnosed with breast cancer.
• If one 1st degree relative has been diagnosed with breast cancer in both breasts and is under the age of 50.

Relative Degrees

1st degree relative, 2nd degree relative, and 3rd degree relative are all terms that are used to depict how close a family member is. The closer the relatives diagnosed with cancer, the greater your risk of developing the disease.

1. 1st degree relatives are the mother, father, brothers, sisters, or children. You share 50% of your genes with them.
2. 2nd degree relatives are grandmothers, grandfathers, grandchildren, aunts, uncles, nieces, nephews, half-brothers, and half-sisters.
3. 3rd degree relative are great-grandparents, great-grandchildren, and first-cousins.

Your doctor may also refer you to breast cancer screening and assessment if you have one 1st degree or one 2nd degree relative that has been diagnosed with breast cancer after the age of 40 and they also have one of the following:

Your doctor may recommend a breast cancer screening if you have one 1st degree or one 2nd degree relative that has been diagnosed with breast cancer after the age of 40. A screening will especially be advised if this individual also has any of the following:

• Cancer in both breasts (bilateral).
• Cancer of the bone or soft tissue (also known as sarcoma) in a relative younger than the age of 45.
• Ovarian cancer.
• Glioma - a type of tumor that develops in the brain.
• Childhood adrenal cortical carcinomas.
• A family history of cancer in a male relative.
• Two or more relatives with breast cancer on the father’s side of the family.
• Is of Jewish descent.

Family History Concerns

If you are concerned about your personal history or family history of breast cancer, you should talk to a healthcare professional. They will likely ask you questions about your family so it is a good idea to get all the facts before seeing them - such as who in your family has been diagnosed with breast cancer or other cancers, at what age they were diagnosed, and how close of a family member they are. Depending on the level of your risk, breast cancer screening and assessment may be in order. Breast cancer screening does not decrease the risk of developing breast cancer, but it does increase the chance of detecting it at an early stage and determining a proper treatment plan.

Determining Your Breast Cancer Risk Level

To determine your level of risk, you will be asked by your doctor to fill out a questionnaire about your family history. The questionnaire will likely include relevant information such as:

• Your medical history and any personal history of breast cancer.
• Your ethnicity.
• Any types of cancers within your family.
• The type of cancer that each relative within your family has been diagnosed with.
• The number of close relatives who have been diagnosed with cancer.
• The number of relatives who have been diagnosed with cancer and who are related to one another.
• The ages of each relative diagnosed with breast cancer or another type of cancer.

After providing the necessary information about your family history and blood relatives, your breast cancer specialist team will have sufficient information to determine your level of risk. However, keep in mind that this does not guarantee that you will develop breast cancer nor does it mean that your level of risk cannot change over the course of your life.

• Low risk: Your risk of developing breast cancer is the same as the rest of the general population, though you should continue to be aware of any body changes – breast pain, nipple discharge, etc.
• Medium risk: Your risk of developing breast cancer is slightly heightened in comparison to the rest of the general population. Depending on your age, it may be necessary for you to undergo a mammogram and routine breast cancer screening.
• High risk: Your risk of developing breast cancer is higher than that of the general population. You may require advice from a healthcare professional on what measures you can take to reduce your risk – in terms of surgical procedures, lifestyle changes, as well as further medical examination.

Whatever your level of risk may be, your doctor and specialist team will offer you all the relevant information and support you require. It is also essential that you inform your doctor of any recent changes within your family, in terms of cancer diagnosis.

Healthy Lifestyle Choices to Consider

While not all healthy lifestyle choices lower the risk of developing breast cancer, they are nonetheless good for your overall well-being.

• Be physically active and aim to exercise on a regular basis.
• Eat lots of nutritious foods - including lots of fruits and vegetables daily.
• Limit red meat to a minimum. Instead, consider eating chicken or fish more often.
• Limit foods high in saturated and trans-fat – such as red meat, fried foods, donuts, and margarine.
• Eat foods rich in polyunsaturated and monounsaturated fats – such as olives, olive oil, nuts, and avocados.
• Eat plenty of 100% whole grain foods – such as brown rice, quinoa, and whole grain breads.
• Maintain a healthy weight.
• Limit excessive intake of alcohol.

Breast cancer is the second most common cancer in the United States. Most breast cancers occur by chance and not due to genetic predisposition. If you or one of your relatives have been diagnosed with the disease, it does not automatically increase your risk or the risk of other family members. Still, a small percentage of individuals may have an increased risk of developing breast cancer due to a significant family history of the disease. For such families, it is recommended to seek guidance from family cancer clinics and consider possible genetic testing. In any case, if you are concerned about your risk of developing breast cancer, speak with your GP about breast cancer awareness, breast cancer screening, and genetic counseling.