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Learning about breast cancer: My House

What are breast cancer risk factors?

Breast cancer risk factors are things that put you at higher risk for having breast cancer. Breast cancer risk factors may include:

  • Gender: Being a woman is the main breast cancer risk factor. Although men can and do get breast cancer, it is 100 times more common in women than in men
  • Age: The breast cancer risk goes up as you get older
  • Your health history: Having had breast cancer in the past increases the risk for developing a new breast cancer in the future. The new cancer can occur either in the same breast or in the other breast. This is not the same as a recurrence (return) of the first cancer
  • Getting your first period early: Women who had their first period before age 12 have a slightly higher risk for breast cancer than women who had their first period after age 12
  • Getting your last period late: Women who have their last period (enter menopause) at a later age (after age 55) have a slightly higher risk of breast cancer than women who have their last period at an earlier age
  • Hormone therapy after menopause: Hormone therapies that combine estrogen and progesterone to relieve the symptoms of menopause increase the risk of breast cancer
  • Having a close family member who has had breast cancer: You have a greater chance of having breast cancer if your mother, sister, or daughter has had breast cancer
  • Race: White women are at a slightly higher risk for breast cancer than are women of other races. But in women under the age of 45, breast cancer is more common in African Americans
  • Having children: Women who have had no children or who had their first child after the age of 30 have a slightly higher risk of breast cancer than women who had their first child before the age of 30

DNA Mutations and the Risk of Breast Cancer

Certain inherited DNA changes, or mutations, can increase the risk of getting breast cancer. These DNA changes are responsible for breast cancer that seems to run in some families. DNA is the chemical in our cells that makes up our genes and provides the instructions for how our cells function.

The most common cause of hereditary breast cancer is an inherited mutation in the BRCA1 and BRCA2 genes. Normally, the BRCA genes help prevent breast cancer by making proteins that keep breast cells from growing abnormally. When these genes are mutated, they no longer suppress abnormal cell growth, and breast cancer is more likely to develop. Genetic testing can identify women who have inherited BRCA1 or BRCA2 mutations, as well as other genetic mutations. These women can then take steps to lower their risk of getting breast cancer and to monitor their breast carefully.

Be sure to talk with your doctor or healthcare provider about your breast cancer risk factors.

To the right are examples of organizations and resources you may find helpful. Click on the links to visit those websites and learn more.


How is breast cancer diagnosed?

There are many ways to screen for breast cancer. Talk with your doctor or healthcare provider about which tests and exams are right for you. Your doctor or healthcare provider can answer your questions about the tests and exams he or she recommends for you and what each test or exam involves.

  • Physical exam and history: The body is checked for signs of disease, such as lumps or anything else that seems unusual. Also, your medical history, including past illnesses and treatments as well as habits (such as smoking), will be reviewed
  • Clinical breast exam: Your doctor or healthcare provider will carefully feel your breasts and check under your arms for lumps or anything else that seems unusual
  • Risk assessment: The risk for developing breast cancer varies from woman to woman. Some women have an increased breast cancer risk, such as those who have had radiotherapy in the chest for other conditions, a strong family history of breast cancer or genetic risk for the disease, or previous breast cancer. Your doctor or healthcare provider will evaluate your breast cancer risk and may recommend certain screening tests based on your risk
  • Mammogram: A mammogram is an x-ray of the breast
    • Screening mammograms are used to look for breast cancer in women who have no breast cancer symptoms. Often, screening mammograms can find a lump before it can be felt. Screening mammograms usually include 2 x-ray pictures of each breast taken from different angles. Ask your doctor or healthcare provider when you should start having screening mammograms and how often you should have them
    • Diagnostic mammograms are used to diagnose breast cancer in women who have an abnormal mammogram result or breast cancer symptoms, such as a lump or discharge from the nipple. Diagnostic mammograms include more images of an area of concern. These additional images can help doctors and healthcare providers understand if the area of abnormal breast tissue is likely to be benign (not cancer) or is suspicious and needs further tests to find out if it is breast cancer
  • Magnetic resonance imaging (MRI): MRI scans use radio waves and strong magnets to look at breast tissue. MRI provides very detailed images of the breast. It is sometimes used, along with mammograms, to screen women who have a high risk of breast cancer. It is also used to better examine any suspicious areas found by a mammogram or to learn more about a tumor in someone whose breast cancer has already been diagnosed
  • Ultrasound exam: An ultrasound scan uses high-energy sound waves (ultrasound) to form pictures of the breast, called sonograms. Ultrasound is usually used to focus on a specific area of concern found on a mammogram. An ultrasound exam helps tell the difference between a solid tumor and a cyst (a sac filled with fluid) in the breast. It can also help tell the difference between cancerous and benign (noncancerous) tumors
  • Ductogram: A ductogram is a test that is sometimes used to help find out what is causing nipple discharge. The test is also called a galactogram
  • Biopsy: A biopsy involves the removal of cells or tissue, which are then looked at under a microscope to see if they are cancerous. There are 4 types of biopsies:
    • Excisional biopsy: The removal of an entire lump of breast tissue
    • Incisional biopsy: The removal of part of a lump or a sample of breast tissue
    • Core biopsy: The removal of breast tissue using a wide needle
    • Fine-needle aspiration (FNA) biopsy): The removal of breast tissue or fluid using a thin needle
  • Blood chemistry studies: Blood chemistry studies are used to measure the amounts of certain substances in the blood. Amounts that are higher or lower than normal could be a sign of breast cancer

To the right are examples of organizations and resources you may find helpful. Click on the links to visit those websites and learn more.


Testing for HER2-positive breast cancer

If you have breast cancer, your doctor or healthcare provider will test your tumor using biomarker tests to find out if it is HER2 positive. Biomarker tests look for molecular signatures called biomarkers. Biomarker tests look for proteins on the surface of cancer cells, changes in the chromosomes of cancer cells, and changes in the DNA sequence taken from cancer cells.

There are 2 ways to test for HER2:

  • Immunohistochemistry (IHC) is a test that counts how much HER2 protein is present on the surface of the breast tumor cell. In HER2-positive breast cancer tumors, the amount of HER2 protein is high
  • Fluorescence in situ hybridization (FISH) is a test that counts the number of copies of the HER2 gene inside each breast cancer cell. In HER2-positive breast cancer tumors, there are too many copies of the HER2 gene

It is very important to have biomarker tests that show your HER2 tumor status since there are medicines that are specifically designed to target this fast-growing, aggressive type of breast cancer.

Be sure to ask your doctor or healthcare provider about HER2 tumor testing to find out if your breast cancer is HER2 positive. If your breast cancer is HER2 positive, talk with your doctor or healthcare provider about the treatment or treatments that might work best for you.

To the right are examples of organizations and resources you may find helpful. Click on the links to visit those websites and learn more.

HER2-normal breast cancer cell HER2-normal breast cancer cell
  • IHC (immunohistochemistry) tests show how much of the HER2 protein is present on the tumor cell surface
  • Protein
  • Cell
HER2+ Breast cancer cell HER2+ Breast cancer cell
  • FISH (fluorescence in situ hybridization) tests measure the number of copies of the HER2 gene inside each cell
  • DNA
  • Nucleus

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