What Causes Breast Cancer?

What Causes Breast Cancer?

Certain changes in DNA can cause normal breast cells to become cancerous. DNA is the chemical in each of our cells that makes up our genes -- the instructions for how our cells work. Some inherited DNA changes can increase the risk for developing cancer and are responsible for the cancers that run in some families. But most breast cancer DNA changes happen in single breast cells during a woman's life rather than having been inherited. These are called acquired changes, and most breast cancers have several of these acquired gene mutations. But so far, the causes of most acquired mutations that could lead to breast cancer remain unknown.

While we do not yet know exactly what causes breast cancer, we do know that certain risk factors are linked to the disease. A risk factor is anything that affects a person's chance of getting a disease such as cancer. Different cancers have different risk factors. Some risk factors, such as smoking, drinking, and diet are linked to things a person does. Others, like a person's age, race, or family history, can't be changed. But risk factors don't tell us everything. Having a risk factor, or even several, doesn't mean that a person will get the disease. Some women who have one or more risk factors never get breast cancer. And most women who do get breast cancer don't have any risk factors. While all women are at risk for breast cancer, the factors listed below can increase a woman's chances of having the disease.

Although many risk factors may increase your chance of developing breast cancer, it is not yet known exactly how some of these risk factors cause cells to become cancerous. Hormones seem to play a role in many cases of breast cancer, but just how this happens is not fully understood.

Risk Factors

• Risk factors you cannot change
• Breast cancer risk and lifestyle choices
• Uncertain risk factors

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Can Breast Cancer Be Prevented?

There is no sure way to prevent breast cancer. But there are things all women can do that might reduce their risk and help increase the odds that if cancer does occur, it is found at an early, more treatable stage.

Lowering your risk: You can lower your risk of breast cancer by changing those risk factors that can be changed. If you limit alcohol use, exercise regularly, and keep a healthy weight, you are decreasing your risk of getting breast cancer. Women who choose to breast-feed for at least several months may also reduce their breast cancer risk. Not using post-menopausal hormone therapy (PHT) if you don't need it can also help you avoid raising your risk.

Finding breast cancer early: It is also important for women to follow the guidelines for finding breast cancer early.

For women who are or may be at increased risk

If you have a higher risk for breast cancer there may be some things you can do to reduce your chances of getting breast cancer. Before deciding which, if any, of these may be right for you, talk with your doctor.

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