Breast Cancer

• Introduction
• The Breasts
• Understanding the Cancer Process
• Breast Cancer: Who’s at Risk?
• Detecting Breast Cancer
• Recognizing Symptoms
• Diagnosing Breast Cancer
• Biopsy
• When Cancer Is Found
• Planning Treatment
• Second Opinion
• Methods of Treating Breast Cancer
• Treatment Choices
• Side Effects of Treatment
• Surgery
• Radiation Therapy
• Chemotherapy
• Hormonal Therapy
• Biological Therapy
• Breast Reconstruction
• Rehabilitation
• Follow-up Care
• Support for Women with Breast Cancer
• The Promise of Cancer Research
• Causes and Prevention
• Detection and Diagnosis
• Treatment
• National Cancer Institute Booklets
• National Cancer Institute Information Resources

Introduction

Other than skin cancer, breast cancer is the most common type of cancer among women in the United States. More than 180,000 women are diagnosed with breast cancer each year. The National Cancer Institute (NCI) has written this booklet to help patients with breast cancer and their families and friends better understand this disease. We hope others will read it as well to learn more about breast cancer.

This booklet discusses screening and early detection, symptoms, diagnosis, treatment, and rehabilitation. It also has information to help patients cope with breast cancer.

Words that may be new to readers are printed in italics. Definitions of these and other terms related to breast cancer are listed in the Dictionary section. For some words, a “sounds-like” spelling is also given.

Research has led to progress against breast cancer–better treatments, a lower chance of death from the disease, and improved quality of life. Through research, knowledge about breast cancer keeps increasing. Scientists are learning more about what causes breast cancer and are exploring new ways to prevent, detect, diagnose, and treat this disease.

The Cancer Information  Service at 1-800-4-CANCER and other NCI resources listed under “National Cancer Institute Information Resources” can provide the latest, most accurate information on breast cancer. Publications listed in the “National Cancer Institute Booklets” section are available from the Cancer Information Service. Also, many NCI publications may be viewed or ordered on the Internet at http://cancer.gov/publications.

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The Breasts

Each breast has 15 to 20 sections called lobes. Within each lobe are many smaller lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are all linked by thin tubes called ducts. These ducts lead to the nipple in the center of a dark area of skin called the areola. Fat surrounds the lobules and ducts. There are no muscles in the breast, but muscles lie under each breast and cover the ribs.

Each breast also contains blood vessels and lymph vessels. The lymph vessels carry colorless fluid called lymph, and lead to small bean-shaped organs called lymph nodes. Clusters of lymph nodes are found near the breast in the axilla(under the arm), above the collarbone, and in the chest. Lymph nodes are also found in many other parts of the body.

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Understanding the Cancer Process

Cancer is a group of many related diseases that begin in cells, the body’s basic unit of life. To understand cancer, it is helpful to know what happens when normal cells become cancerous.

The body is made up of many types of cells. Normally, cells grow and divide to produce more cells only when the body needs them. This orderly process helps keep the body healthy. Sometimes, however, cells keep dividing when new cells are not needed. These extra cells form a mass of tissue, called a growth or tumor. Tumors can be benign or malignant.

• Benign tumors are not cancer. They can usually be removed, and in most cases, they do not come back. Cells from benign tumors do not spread to other parts of the body. Most important, benign breast tumors are not a threat to life.
• Malignant tumors are cancer. Cells in these tumors are abnormal. They divide without control or order, and they can invade and damage nearby tissues and organs. Also, cancer cells can break away from a malignant tumor and enter the bloodstream or the lymphatic system. That is how cancer spreads from the original (primary) cancer site to form new tumors in other organs. The spread of cancer is called metastasis.

When cancer arises in breast tissue and spreads (metastasizes) outside the breast, cancer cells are often found in the lymph nodes under the arm (axillary lymph nodes). If the cancer has reached these nodes, it means that cancer cells may have spread to other parts of the body–other lymph nodes and other organs, such as the bones, liver, or lungs. When cancer spreads from its original location to another part of the body, the new tumor has the same kind of abnormal cells and the same name as the primary tumor. For example, if breast cancer spreads to the brain, the cancer cells in the brain are actually breast cancer cells. The disease is called metastatic breast cancer. (It is not brain cancer.) Doctors sometimes call this “distant” disease.

This booklet deals with breast cancer. For information about benign breast lumps and other benign breast changes, read NCI’s booklet, Understanding Breast Changes: A Health Guide for All Women.

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Breast Cancer: Who’s at Risk? 

The exact causes of breast cancer are not known. However, studies show that the risk of breast cancer increases as a woman gets older. This disease is very uncommon in women under the age of 35. Most breast cancers occur in women over the age of 50, and the risk is especially high for women over age 60. Also, breast cancer occurs more often in white women than African American or Asian women.

Research has shown that the following conditions increase a woman’s chances of getting breast cancer:

• Personal history of breast cancer. Women who have had breast cancer face an increased risk of getting breast cancer in their other breast.
• Family history. A woman’s risk for developing breast cancer increases if her mother, sister, or daughter had breast cancer, especially at a young age.
• Certain breast changes. Having a diagnosis of atypical hyperplasia or lobular carcinoma in situ(LCIS) may increase a woman’s risk for developing cancer.
• Genetic alterations. Changes in certain genes(BRCA1, BRCA2, and others) increase the risk of breast cancer. In families in which many women have had the disease, gene testing can sometimes show the presence of specific genetic changes that increase the risk of breast cancer. Doctors may suggest ways to try to delay or prevent breast cancer, or to improve the detection of this disease in women who have these changes in their genes. For more information about gene testing, read the “Causes and Prevention” section under “The Promise of Cancer Research.”

Other factors associated with an increased risk for breast cancer include:

• Estrogen. Evidence suggests that the longer a woman is exposed toe strogen(estrogen made by the body, taken as a drug, or delivered by a patch), the more likely she is to develop breast cancer. For example, the risk is somewhat increased among women who began menstruation at an early age (before age 12), experienced menopause late (after age 55), never had children, or took hormone replacement therapy for long periods of time. Each of these factors increases the amount of time a woman’s body is exposed to estrogen.DES (diethylstilbestrol) is a synthetic form of estrogen that was used between the early 1940s and 1971. Women who took DES during pregnancy to prevent certain complications are at a slightly higher risk for breast cancer. This does not appear to be the case for their daughters who were exposed to DES before birth. However, more studies are needed as these daughters enter the age range when breast cancer is more common.
• Late childbearing. Women who have their first child late (after about age 30) have a greater chance of developing breast cancer than women who have a child at a younger age.
• Breast density. Breasts that have a high proportion of lobular and ductal tissue appear dense on mammograms. Breast cancers nearly always develop in lobular or ductal tissue (not fatty tissue). That’s why cancer is more likely to occur in breasts that have a lot of lobular and ductal tissue (that is, dense tissue) than in breasts with a lot of fatty tissue. In addition, when breasts are dense, it is more difficult for doctors to see abnormal areas on a mammogram.
• Radiation therapy. Women whose breasts were exposed to radiation during radiation therapy before age 30, especially those who were treated with radiation for Hodgkin’s disease, are at an increased risk for developing breast cancer. Studies show that the younger a woman was when she received her treatment, the higher her risk for developing breast cancer later in life.
• Alcohol. Some studies suggest a slightly higher risk of breast cancer among women who drink alcohol.

Most women who develop breast cancer have none of the risk factors listed above, other than the risk that comes with growing older. Scientists are conducting research into the causes of breast cancer to learn more about risk factors and ways of preventing this disease.

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Detecting Breast Cancer 

Women should talk with their doctor about factors that can increase their chance of getting breast cancer. Women of any age who are at higher risk for developing this disease should ask their doctor when to start and how often to be checked for breast cancer. Breast cancer screening has been shown to decrease the risk of dying from breast cancer.

Women can take an active part in the early detection of breast cancer by having regularly scheduled screening mammograms and clinical breast exams (breast exams performed by health professionals). Some women also perform breast self-exams.

A screening mammogram is the best tool available for finding breast cancer early, before symptoms appear. A mammogram is a special kind of x-ray. Screening mammograms are used to look for breast changes in women who have no signs of breast cancer.

Mammograms can often detect a breast lump before it can be felt. Also, a mammogram can show small deposits of calcium in the breast. Although most calcium deposits are benign, a cluster of very tiny specks of calcium (called microcalcifications) may be an early sign of cancer.

If an area of the breast looks suspicious on the screening mammogram, additional (diagnostic) mammograms may be needed. Depending on the results, the doctor may advise the woman to have a biopsy.

Although mammograms are the best way to find breast abnormalities early, they do have some limitations. A mammogram may miss some cancers that are present (false negative) or may find things that turn out not to be cancer (false positive). And detecting a tumor early does not guarantee that a woman’s life will be saved. Some fast-growing breast cancers may already have spread to other parts of the body before being detected.

Nevertheless, studies show that mammograms reduce the risk of dying from breast cancer. Most doctors recommend that women in their forties and older have mammograms regularly, every 1 to 2 years.

Some women perform monthly breast self-exams to check for any changes in their breasts. When doing a breast self-exam, it’s important to remember that each woman’s breasts are different and that changes can occur because of aging, the menstrual cycle, pregnancy, menopause, or taking birth control pills or other hormones. It is normal for the breasts to feel a little lumpy and uneven. Also, it is common for a woman’s breasts to be swollen and tender right before or during her menstrual period. Women in their forties and older should be aware that a monthly breast self-exam is not a substitute for regularly scheduled screening mammograms and clinical breast exams by a health professional.

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Recognizing Symptoms

Early breast cancer usually does not cause pain. In fact, when breast cancer first develops, there may be no symptoms at all. But as the cancer grows, it can cause changes that women should watch for:

• A lump or thickening in or near the breast or in the underarm area;
• A change in the size or shape of the breast;
• Nipple discharge or tenderness, or the nipple pulled back (inverted) into the breast;
• Ridges or pitting of the breast (the skin looks like the skin of an orange); or
• A change in the way the skin of the breast, areola, or nipple looks or feels (for example, warm, swollen, red, or scaly).

A woman should see her doctor about any symptoms like these. Most often, they are not cancer, but it’s important to check with the doctor so that any problems can be diagnosed and treated as early as possible.

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Diagnosing Breast Cancer

To help find the cause of any sign or symptom, a doctor does a careful physical exam and asks about personal and family medical history. In addition, the doctor may do one or more breast exams:

• Clinical breast exam. The doctor can tell a lot about a lump by carefully feeling it and the tissue around it. Benign lumps often feel different from cancerous ones. The doctor can examine the size and texture of the lump and determine whether the lump moves easily.
• Mammography. X-rays of the breast can give the doctor important information about a breast lump.
• Ultrasonography. Using high-frequency sound waves, ultrasonography can often show whether a lump is a fluid-filledcyst(not cancer) or a solid mass (which may or may not be cancer). This exam may be used along with mammography.

Based on these exams, the doctor may decide that no further tests are needed and no treatment is necessary. In such cases, the doctor may need to check the woman regularly to watch for any changes.

Biopsy

Often, fluid or tissue must be removed from the breast so the doctor can make a diagnosis. A woman’s doctor may refer her for further evaluation to a surgeon or other health care professional who has experience with breast diseases. These doctors may perform:

• Fine-needle aspiration. A thin needle is used to remove fluid and/or cells from a breast lump. If the fluid is clear, it may not need to be checked by a lab.
• Needle biopsy. Using special techniques, tissue can be removed with a needle from an area that looks suspicious on a mammogram but cannot be felt. Tissue removed in a needle biopsy goes to a lab to be checked by a pathologist for cancer cells.
• Surgical biopsy. In an incisional biopsy, the surgeon cuts out a sample of a lump or suspicious area. In an excisional biopsy, the surgeon removes all of a lump or suspicious area and an area of healthy tissue around the edges. A pathologist then examines the tissue under a microscope to check for cancer cells.

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When Cancer Is Found

The most common type of breast cancer is ductal carcinoma. It begins in the lining of the ducts. Another type, called lobular carcinoma, arises in the lobules. When cancer is found, the pathologist can tell what kind of cancer it is (whether it began in a duct or a lobule) and whether it is invasive (has invaded nearby tissues in the breast).

Special lab tests of the tissue help the doctor learn more about the cancer. For example, hormone receptor tests(estrogen and progesteronereceptor tests) can help determine whether hormones help the cancer to grow. If test results show that hormones do affect the cancer’s growth (a positive test result), the cancer is likely to respond to hormonal therapy. This therapy deprives the cancer cells of estrogen. More information about hormonal therapy can be found in the “Planning Treatment” section.

Other tests are sometimes done to help the doctor predict whether the cancer is likely to progress. For example, the doctor may order x-rays and lab tests. Sometimes a sample of breast tissue is checked for a gene (the human epidermal growth factor receptor-2 or HER-2 gene) that is associated with a higher risk that the breast cancer will come back. The doctor may also order special exams of the bones, liver, or lungs because breast cancer may spread to these areas.

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Planning Treatment 

Many women with breast cancer want to take an active part in decisions about their medical care. They want to learn all they can about their disease and their treatment choices. However, the shock and stress that people often feel after a diagnosis of cancer can make it hard for them to think of everything they want to ask the doctor. Often it is helpful to prepare a list of questions in advance. To help remember what the doctor says, patients may take notes or ask whether they may use a tape recorder. Some people also want to have a family member or friend with them when they talk to the doctor–to take part in the discussion, to take notes, or just to listen.

The patient’s doctor may refer her to doctors who specialize in treating cancer, or she may ask for a referral. Treatment generally begins within a few weeks after the diagnosis. There will be time for the woman to talk with the doctor about her treatment choices, to get a second opinion, and to prepare herself and her loved ones.

Second Opinion

Before starting treatment, the patient might want a second opinion about the diagnosis and the treatment plan. Some insurance companies require a second opinion; others may cover a second opinion if the woman requests it. It may take a little while to arrange to see another doctor. In most cases, a brief delay (up to 3 or 4 weeks) between biopsy and treatment does not make breast cancer treatment less effective. There are a number of ways to find a doctor for a second opinion:

• • The patient’s doctor may refer her to one or more specialists. Specialists who treat women with breast cancer include surgeons,medical oncologists,plastic surgeons, andradiation oncologists. At cancer centers or special centers for breast diseases, these doctors often work together as a team.
  • The Cancer Information Service, at 1-800-4-CANCER, can tell callers about treatment facilities, including cancer centers and other NCI-supported programs, in their area.

• Patients can get the names of specialists from their local medical society, a nearby hospital, or a medical school.
• The Official ABMS Directory of Board Certified Medical Specialists lists doctors’ names along with their speciality and their educational background. This resource, produced by the American Board of Medical Specialties (ABMS), is available in most public libraries. The ABMS also provides an online service to help people locate doctors

Methods of Treating Breast Cancer

Breast cancer may be treated withlocalorsystemictherapy. Some patients have both kinds of treatment.

Local therapy is used to remove or destroy breast cancer in a specific area.Surgeryandradiation therapyare local treatments. They are used to treat the disease in the breast. When breast cancer has spread to other parts of the body, local therapy may be used to control cancer in those specific areas, such as in the lung or bone.

Systemic treatments are used to destroy or control cancer throughout the body.Chemotherapy,hormonal therapy, andbiological therapyare systemic treatments. Some patients have systemic therapy to shrink the tumor before local therapy. Others have systemic therapy to prevent the cancer from coming back, or to treat cancer that has spread.

Surgery is the most common treatment for breast cancer, and there are several types of surgery. The doctor can explain each type, discuss and compare their benefits and risks, and describe how each will affect the patient’s appearance.

• An operation to remove the cancer but not the breast is called breast-sparing surgery orbreast-conserving surgery.Lumpectomyandsegmental mastectomy(also called partial mastectomy) are types of breast-sparing surgery. After breast-sparing surgery, most women receive radiation therapy to destroy cancer cells that remain in the area.
• An operation to remove the breast (or as much of the breast as possible) is amastectomy.Breast reconstructionis often an option at the same time as the mastectomy, or later on.
• In most cases, the surgeon also removes lymph nodes under the arm to help determine whether cancer cells have entered the lymphatic system. This is called anaxillary lymph node dissection