Inside a woman’s breast are 15 to 20 sections lobes. Each lobe is made of many smaller sections lobules. Lobules have groups of tiny glands that can make milk. After a baby is born, breast milk flows from the lobules through thin tubes ducts to the nipple. Fibrous tissue and fat fill the spaces between the lobules and ducts.
Cancer begins in cells, the building blocks that make up all tissues and organs of the body, including the breast.
Normal cells in the breast and other parts of the body grow and divide to form new cells as they are needed. When normal cells grow old or get damaged, they die, and new cells take their place.
Sometimes, this process goes wrong. New cells form when the body doesn’t need them, and old or damaged cells don’t die as they should. The buildup of extra cells often forms a mass of tissue called a growth or tumor. Tumors in the bladder can be benign (not cancer) or malignant (cancer). Benign tumors are not as harmful as malignant tumors:
Tumors in the breast can be benign (not cancer) or malignant (cancer):
Breast cancer cells can spread by breaking away from a breast tumor. They can travel through blood vessels or lymph vessels to reach other parts of the body. After spreading, cancer cells may attach to other tissues and grow to form new tumors that may damage those tissues.
For example, breast cancer cells may spread first to nearby lymph nodes. Groups of lymph nodes are near the breast under the arm axilla, above the collarbone, and in the chest behind the breastbone.
When breast cancer spreads from its original place to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary (original) tumor. For example, if breast cancer spreads to a lung, the cancer cells in the lung are actually breast cancer cells. The disease is metastatic breast cancer, not lung cancer. For that reason, it’s treated as breast cancer, not lung cancer.
Breast cancer is the most common type of cancer among women in the United States (other than skin cancer). In 2013, more than 232,000 American women will be diagnosed with breast cancer.
The most common type of breast cancer is ductal carcinoma. This cancer begins in cells that line a breast duct. See the picture of breast ducts. About 7 of every 10 women with breast cancer have ductal carcinoma.
The second most common type of breast cancer is lobular carcinoma. This cancer begins in a lobule of the breast. See the picture of lobules. About 1 of every 10 women with breast cancer has lobular carcinoma.
Other women have a mixture of ductal and lobular type or they have a less common type of breast cancer.
After you find out that you have breast cancer, you may need other tests to help choose the best treatment for you.
The breast tissue that was removed during your biopsy can be used in special lab tests:
It may take several weeks to get the results of these tests. The test results help your doctor decide which cancer treatments may be options for you.
About 15 of every 100 American women with breast cancer have triple-negative breast cancer. These women have breast cancer cells that
Staging tests can show whether cancer cells have spread to other parts of the body.
When breast cancer spreads, cancer cells are often found in the underarm lymph nodes (axillary lymph nodes). Breast cancer cells can spread from the breast to almost any other part of the body, such as the lungs, liver, bones, or brain.
Your doctor needs to learn the stage (extent) of the breast cancer to help you choose the best treatment. Staging tests may include…
Questions you may want to ask your doctor about tests
The stage of breast cancer depends on the size of the breast tumor and whether it has spread to lymph nodes or other parts of the body.
Doctors describe the stages of breast cancer using the Roman numerals 0, I, II, III, and IV and the letters A, B, and C.
A cancer that is Stage I is early-stage breast cancer, and a cancer that is Stage IV is advanced cancer that has spread to other parts of the body, such as the liver.
The stage often is not known until after surgery to remove the tumor in the breast and one or more underarm lymph nodes.
Stage 0 is carcinoma in situ. In ductal carcinoma in situ (DCIS), abnormal cells are in the lining of a breast duct, but the abnormal cells have not invaded nearby breast tissue or spread outside the duct.
The breast tumor is no more than 2 centimeters (no more than 3/4 of an inch) across. Cancer has not spread to the lymph nodes.
A tumor that is 2 centimeters is about the size of a peanut, and a tumor that is 5 centimeters is about the size of a lime.
The tumor is no more than 2 centimeters across. Cancer cells are found in lymph nodes.
The tumor is no more than 2 centimeters across, and the cancer has spread to underarm lymph nodes.
Or, the tumor is between 2 and 5 centimeters (between 3/4 of an inch and 2 inches) across, but the cancer hasn’t spread to underarm lymph nodes.
The tumor is between 2 and 5 centimeters across, and the cancer has spread to underarm lymph nodes.
Or, the tumor is larger than 5 centimeters across, but the cancer hasn’t spread to underarm lymph nodes.
The breast tumor is no more than 5 centimeters across, and the cancer has spread to underarm lymph nodes that are attached to each other or nearby tissue. Or, the cancer may have spread to lymph nodes behind the breastbone.
Or, the tumor is more than 5 centimeters across. The cancer has spread to underarm lymph nodes that may be attached to each other or nearby tissue. Or, the cancer may have spread to lymph nodes behind the breastbone but not spread to underarm lymph nodes.
The breast tumor can be any size, and it has grown into the chest wall or the skin of the breast. The breast may be swollen or the breast skin may have lumps.
The cancer may have spread to underarm lymph nodes, and these lymph nodes may be attached to each other or nearby tissue. Or, the cancer may have spread to lymph nodes behind the breastbone.
The breast cancer can be any size, and it has spread to lymph nodes behind the breastbone and under the arm. Or, the cancer has spread to lymph nodes above or below the collarbone.
The tumor can be any size, and cancer cells have spread to other parts of the body, such as the lungs, liver, bones, or brain.
Women with breast cancer have many treatment options. Treatment options include…
You may receive more than one type of treatment. The treatment that’s best for one woman may not be best for another. The treatment that’s right for you depends mainly on…
In addition, your treatment plan depends on…
At any stage of disease, care is available to control pain and other symptoms, to relieve the side effects of treatment, and to ease emotional concerns. You can get information about coping on NCI’s website at http://www.cancer.gov/cancertopics/coping.
Your health care team will include specialists. There are many ways to find doctors who treat breast cancer:
Your health care team may include the following specialists:
Your health care team may also include a plastic surgeon or reconstructive surgeon, an oncology nurse, a physical therapist, a social worker, and a registered dietician.
Your health care team can describe your treatment choices, the expected results of each treatment, and the possible side effects. Because cancer treatments often damage healthy cells and tissues, side effects are common. These side effects depend on many factors, including the type of treatment. Side effects may not be the same for each woman, and they may even change from one treatment session to the next.
Before treatment starts, ask your health care team about possible side effects and how treatment may change your normal activities.
You and your health care team can work together to develop a treatment plan that meets your medical and personal needs.
You may want to talk with your health care team about taking part in a research study clinical trial of new treatment methods. Research studies are an important option for women at any stage of breast cancer.
Before starting treatment, you might want a second opinion about your treatment plan. Some women worry that the doctor will be offended if they ask for a second opinion. Usually the opposite is true. Most doctors welcome a second opinion. And many health insurance companies will pay for a second opinion if you or your doctor requests it. Some companies actually require a second opinion.
If you get a second opinion, the second doctor may agree with your first doctor’s treatment plan. Or, the second doctor may suggest another approach. Either way, you have more information and perhaps a greater sense of control. You can feel more confident about the decisions you make, knowing that you’ve looked at all of your options.
It may take some time and effort to gather your medical records and see another doctor. In most cases, it’s not a problem to take several weeks to get a second opinion. The delay in starting treatment usually will not make treatment less effective. To make sure, you should discuss this delay with your doctor.
Surgery is the most common treatment for breast cancer. There are several kinds of surgery.
Your surgeon can describe each kind of surgery, compare the benefits and risks, and help you decide which kind might be best for you:
The choice between breast-sparing surgery and mastectomy depends on many factors:
The surgeon usually removes one or more lymph nodes from under the arm to check for cancer cells. If cancer cells are found in the lymph nodes, other cancer treatments will be needed.
After mastectomy, you may choose to have breast reconstruction. This is plastic surgery to rebuild the shape of the breast. If you’re considering breast reconstruction, talk with a plastic surgeon before having cancer surgery.
It’s common to feel tired or weak for a while after surgery for breast cancer. The time it takes to heal is different for each woman.
Surgery causes pain and tenderness, and the skin where your breast was removed may feel tight. Your arm and shoulder muscles may feel stiff and weak, and your neck and back may hurt. Medicine can help control your pain. Before surgery, discuss the plan for pain relief with your health care team. After surgery, they can adjust the plan if you need more pain control.
Any kind of surgery carries a risk of infection, bleeding, or other problems. Tell your health care team right away if you develop any problems.
Removing the underarm lymph nodes slows the flow of lymph fluid. The fluid may build up in your arm and hand and cause swelling. This swelling is called lymphedema. It can develop soon after surgery or months or even years later.
Always protect the arm and hand on the treated side of your body from cuts, burns, or other injuries. Remind nurses not to measure your blood pressure or give you injections on the treated side of your body.
The doctor, nurse, or physical therapist can suggest exercises to help you regain movement and strength in your arm and shoulder. Exercise can also reduce stiffness and pain. You may be able to begin gentle exercise within days of surgery.
Because nerves may be injured or cut during surgery, you may have numbness and tingling in your chest, underarm, shoulder, or upper arm. These feelings may go away within a few weeks or months.
Questions you may want to ask your doctor about surgery
Radiation therapy uses high-energy rays to kill cancer cells. It affects cells only in the part of the body that is treated.
Radiation therapy may be used after surgery to destroy breast cancer cells that remain in the chest area. Women usually have radiation therapy after breast-sparing surgery, but it’s sometimes used after mastectomy too.
You can get radiation therapy to treat breast cancer in two ways:
Side effects depend mainly on the type of radiation and how much is given. Ask your health care team to describe what you can expect.
It’s common for the skin in the treated area to become red, dry, tender, and itchy. Check with your doctor before using lotion, cream, or deodorant on the treated area. After treatment is over, the skin will slowly heal. However, there may be a lasting change in the color of your skin.
With either type of radiation therapy, your breast may feel heavy and tight. Internal radiation therapy may make your breast look red or bruised. These problems usually go away over time.
Bras and tight clothes may rub your skin and cause soreness. You may want to wear loose-fitting cotton clothes during this time.
You’re likely to become tired during radiation therapy, especially in the later weeks of treatment. Although getting enough rest is important, most people say they feel better when they exercise every day. Try to go for a short walk, do gentle stretches, or do yoga.
You may wish to discuss with your doctor the possible long- term effects of radiation therapy. For example, radiation therapy to the chest may harm the lung or heart. Also, it can change the size of your breast and the way it looks. If any of these problems occur, your health care team can tell you how to manage them.
Questions you may want to ask your doctor about radiation therapy
Hormone therapy can also be called anti-hormone treatment. If lab tests show that your breast cancer cells have hormone receptors, then hormone therapy may be an option. Hormone therapy keeps the cancer cells from getting or using the natural hormones (estrogen and progesterone) they need to grow.
If you have not gone through menopause, the options for hormone therapy include…
If you have gone through menopause, the options include…
The side effects of hormone therapy depend on the type used. The most common side effects are hot flashes, vaginal discharge, and nausea.
The NCI fact sheet Hormone Therapy for Breast Cancer has information about the use and side effects of hormone therapy.
Chemotherapy uses drugs to kill cancer cells. It may be given to women with Stage I, II, III, or IV breast cancer. Chemotherapy may be given before or after surgery.
The drugs for breast cancer are usually given directly into a vein (intravenously) through a thin needle or as a pill. You may receive a combination of drugs.
You may receive chemotherapy in a clinic, at the doctor’s office, or at home. It’s unusual for a woman to need to stay in the hospital during treatment.
The side effects depend mainly on which drugs are given and how much. Chemotherapy kills fast-growing cancer cells, but the drugs can also harm normal cells that divide rapidly:
Some drugs used for breast cancer can cause tingling or numbness in the hands or feet. This problem often goes away after treatment is over.
Other problems may not go away. For example, some of the drugs used for breast cancer may weaken the heart. Your doctor may check your heart before, during, and after treatment. A rare side effect of chemotherapy is that years after treatment, a few women have developed leukemia (cancer of the blood cells).
If you have not yet gone through menopause, some anticancer drugs may damage the ovaries and cause hot flashes, vaginal dryness, and other menopause symptoms. Your menstrual periods may no longer be regular or may stop, and you may lose the ability to become pregnant. The older you are, the more likely that this damage to the ovaries will be permanent. Women who may want to get pregnant later on should ask their health care team about ways to preserve their eggs before treatment starts.
On the other hand, other anticancer drugs don’t damage the ovaries and you may remain able to become pregnant during chemotherapy. Before treatment begins, talk with your doctor about birth control because many anticancer drugs given during the first trimester are known to cause birth defects.
The NCI booklet Chemotherapy and You has ideas for coping with side effects.
Women whose lab tests show that their breast cancer cells have too much HER2 protein may receive targeted therapy. The targeted therapies used to treat breast cancer block cancer cell growth by blocking the action of the extra HER2 protein.
These drugs may be given intravenously or as a pill. The side effects depend mainly on which drug is given. Possible side effects include nausea, vomiting, and diarrhea. The drugs may also cause heart damage, heart failure, and serious breathing problems. During treatment, your doctor will watch for signs of heart and lung problems.
You may want to read the NCI fact sheet Targeted Cancer Therapies
A woman who plans to have a mastectomy has a choice about whether or not to have surgery to rebuild the shape of the breast (breast reconstruction). Instead of breast reconstruction, a woman could choose to wear a breast form (a device that replaces the breast), wear padding inside her bra, or do nothing. All of these options have pros and cons. What is right for one woman may not be right for another.
Breast reconstruction may be done at the same time as the mastectomy, or it may be done later on. If radiation therapy is part of the treatment plan, some doctors suggest waiting until after radiation therapy is complete.
If you’re thinking about breast reconstruction, talk to a plastic surgeon before the mastectomy, even if you plan to have your reconstruction later on.
A surgeon can reconstruct the breast in many ways. Some women choose to have breast implants, which are filled with saline or silicone gel.
Another method of breast reconstruction is to create a breast shape using tissue taken from another part of your body. The plastic surgeon can take skin, muscle, and fat from your lower abdomen, back, or buttocks.
The type of reconstruction that is best for you depends on your age, body type, and the type of cancer surgery that you had. A plastic surgeon can help you decide.
Questions you may want to ask your doctor about breast reconstruction
Eating well is important before, during, and after cancer treatment. You need the right amount of calories to maintain a good weight. You also need enough protein to keep up your strength. Eating well may help you feel better and have more energy.
Sometimes, especially during or soon after treatment, you may not feel like eating. You may be uncomfortable or tired. You may find that foods don’t taste as good as they used to. In addition, poor appetite, nausea, vomiting, mouth blisters, and other side effects of treatment can make it hard for you to eat. On the other hand, some women treated for breast cancer may have a problem with weight gain.
Your doctor, a registered dietitian, or another health care provider can suggest ways to help you meet your nutrition needs. Also, the NCI booklet Eating Hints has many useful recipes and lists of foods that can help with side effects.
You’ll need regular checkups (such as every 3 to 6 months) after treatment for breast cancer. Checkups help ensure that any changes in your health are noted and treated if needed. If you have any health problems between checkups, contact your doctor. Checkups help detect…
Checkups usually include an exam of the neck, underarm, chest, and breast areas. Since a new breast cancer may develop, you should have regular mammograms. You probably won’t need a mammogram of a reconstructed breast or if you had a mastectomy without reconstruction. Your doctor may order other imaging procedures or lab tests.
Learning that you have breast cancer can change your life and the lives of those close to you. These changes can be hard to handle.
Concerns about treatments and managing side effects, hospital stays, and medical bills are common. You may also worry about caring for your family, keeping your job, or continuing daily activities. It’s normal for you, your family, and your friends to need help coping with such worries.
Several organizations offer special programs for women with breast cancer. Women who have had the disease serve as trained volunteers. They may talk with or visit women who have breast cancer, provide information, and lend emotional support. They often share their experiences with breast cancer treatment, breast reconstruction, and recovery.
Here’s where you can go for support:
For tips on coping, you may want to read the NCI booklet Taking Time: Support for People With Cancer.
Doctors all over the world are conducting many types of cancer treatment studies (clinical trials) in which people volunteer to take part. Research has already led to advances in the prevention, detection, and treatment of breast cancer.
Doctors continue to search for new and better ways to treat breast cancer. NCI is sponsoring many studies with women who have breast cancer, such as studies that combine surgery, chemotherapy, hormone therapy, and radiation therapy.
Even if a woman in a research study doesn’t benefit directly from the treatment under study, she may still make an important contribution by helping doctors learn more about breast cancer and how to control it. Although research studies may pose some risks, researchers do all they can to protect their patients.
If you’re interested in being part of a research study, talk with your doctor. You may want to read the NCI booklet Taking Part in Cancer Treatment Research Studies. It describes how treatment studies are carried out and explains their possible benefits and risks.