If you or a loved one has been diagnosed with breast cancer, it's important to understand some basics: What is breast cancer and how does it happen?
In this section, you can learn about how breast cancer develops, how many people get breast cancer, and what factors can increase risk for getting breast cancer. You also can learn more about signs and symptoms to watch for and how to manage any fears you may have about breast cancer.
Breast cancer is an uncontrolled growth of breast cells. To better understand breast cancer, it helps to understand how any cancer can develop.
Cancer occurs as a result of mutations, or abnormal changes, in the genes responsible for regulating the growth of cells and keeping them healthy. The genes are in each cell’s nucleus, which acts as the “control room” of each cell. Normally, the cells in our bodies replace themselves through an orderly process of cell growth: healthy new cells take over as old ones die out. But over time, mutations can “turn on” certain genes and “turn off” others in a cell. That changed cell gains the ability to keep dividing without control or order, producing more cells just like it and forming a tumor.
A tumor can be benign (not dangerous to health) or malignant (has the potential to be dangerous). Benign tumors are not considered cancerous: their cells are close to normal in appearance, they grow slowly, and they do not invade nearby tissues or spread to other parts of the body. Malignant tumors are cancerous. Left unchecked, malignant cells eventually can spread beyond the original tumor to other parts of the body.
The term “breast cancer” refers to a malignant tumor that has developed from cells in the breast. Usually breast cancer either begins in the cells of the lobules, which are the milk-producing glands, or the ducts, the passages that drain milk from the lobules to the nipple. Less commonly, breast cancer can begin in the stromal tissues, which include the fatty and fibrous connective tissues of the breast.
Over time, cancer cells can invade nearby healthy breast tissue and make their way into the underarm lymph nodes, small organs that filter out foreign substances in the body. If cancer cells get into the lymph nodes, they then have a pathway into other parts of the body. The breast cancer’s stage refers to how far the cancer cells have spread beyond the original tumor (see Stages of Breast Cancer table for more information).
Breast cancer is always caused by a genetic abnormality (a “mistake” in the genetic material). However, only 5-10% of cancers are due to an abnormality inherited from your mother or father. About 90% of breast cancers are due to genetic abnormalities that happen as a result of the aging process and the “wear and tear” of life in general.
While there are steps every person can take to help the body stay as healthy as possible (such as eating a balanced diet, not smoking, limiting alcohol, and exercising regularly), breast cancer is never anyone's fault. Feeling guilty, or telling yourself that breast cancer happened because of something you or anyone else did, is not productive.
Managing Breast Cancer Fears
So many women you know may have had breast cancer — friends and neighbors, coworkers, relatives. It seems as if every time you turn around, breast cancer is being talked about in the newspaper or on TV. You may be fearful of developing breast cancer for the first time or of receiving a diagnosis after a mammogram or other testing. If you’ve had breast cancer, you may be fearful of a possible recurrence or even of the possibility that breast cancer could take your life.
Even though you may have some of these fears, you are not necessarily going to get breast cancer. If you have had breast cancer before, it doesn’t mean that the cancer will recur. Still, it's normal to have concerns about a disease that you hear about and see around you relatively often — and that you may have experienced yourself or through a loved one. Don't let the discussion of fear in this section feed into your own fears. Throughout Breastcancer.org, the information our medical experts provide and the support offered by our community members can help you manage the fears, instead of letting them manage you.
The fear of breast cancer is unlike any other — psychologists and other experts agree on that. The fear can take many different forms, depending upon where you are in the breast cancer experience. Understand that many of your fears are shared by others. While fears are normal, they are uncomfortable to live with. We'll help you figure out how you can manage fear so you can focus on living a happy and healthy life.
How can I find breast cancer early?
The best way to find breast lumps is to do 3 things:
Have regular mammograms (usually every 2 years starting at age 50. If you are under 50, talk to your doctor about your risk factors for breast cancer, including your family history, to decide whether regular mammogram screenings are appropriate for you).
Have your doctor check your breasts.
Check your breasts yourself every month.
Doing all of these things gives you the best chance to find cancer as early as you can. Finding breast cancer early makes treatment much easier and more effective.
What is a mammogram?
A mammogram is the most effective way to find breast cancer early, up to 2 years before the lump is even large enough to feel. A mammogram is a special kind of X-ray of your breasts. The amount of radiation used in the X-ray is very small and not harmful.
Mammograms detect cancer because cancer is more dense (thicker) than the normal part of the breast. A radiologist will look at the X-rays for signs of cancer or other breast problems.
How is a mammogram performed?
Your breast will rest on a shelf and the X-ray machine will slowly press against your breast until you feel pressure. This pressure is needed to spread your breast out so that a better X-ray can be taken. The X-ray takes 1 or 2 minutes, and the entire process usually takes no more than about 20 minutes.
Do mammograms hurt?
Mammograms can be uncomfortable. But they don't take very long. You may find that planning to have your mammogram shortly after your period makes it less uncomfortable. Your breasts may be less tender at this time.
How often should I get a mammogram?
Women age 50 and over should get a mammogram every 2 years. If you have risk factors for breast cancer, such as a family history of breast cancer, your doctor may want you to have mammograms more often or start having them sooner.
How often should my doctor check my breasts?
Every 1 to 2 years beginning when you're 20. Talk with your doctor when it's time for your breasts to be checked.
How often should I check my breasts?
You should check your breasts every month beginning at about age 20. At this early age, any small lumps are probably just normal breast glands and ducts. Over time you will get used to how your breasts normally feel so that you're able to tell if a new lump appears.
Check your breasts a few days after your period (when your breasts are usually less sore). If you don't have periods or if they come at varying times, check your breasts at the same time every month.
What are the Changes to look for in your breasts?
Any new lump (which may or may not be painful or tender)
Unusual thickening of your breasts
Sticky or bloody discharge from your nipples
Any changes in the skin of your nipples or breasts, such as puckering or dimpling
An unusual increase in the size of one breast
One breast unusually lower than the other
How do I check for lumps?
- Start by standing in front of a mirror. Look at your breasts with your arms at your side, with your arms raised behind your head, and with your arms on your hips and your chest muscles flexed.
- Next, lie down with a pillow under your left shoulder. Put your left hand behind your head and feel your left breast with the pads of the 3 middle fingers on your right hand. Start at the outer edge and work around your breast in small circles, getting closer to your nipple with each circle. After you've finished checking your breast, squeeze your nipple gently and look for discharge (fluid coming out of the nipple).
- Do the same thing to your right breast with a pillow under your right shoulder.
- Be sure to include the area up to your collarbone and out to your armpit. You have lymph nodes in this area. Cancer can spread to lymph node tissue.