Breast Cancer

Breast cancer is cancer arising in breast tissue. Cancer is simply a group of abnormal cells that have abnormal growth patterns.

• Although breast cancer is primarily a disease of women, about 1% of breast cancers occur in men.
  
  
• Breast cancer is the most common type of cancer in women and is the second leading cause of death by cancer in women, following only lung cancer.
  
  
• In 2000, the American Cancer Society estimated that 184,200 new cases of breast cancer were diagnosed in the United States.

The breasts are made of fat, glands, and connective (fibrous) tissue.

• The breast has several lobes, which are divided into lobules and end in the milk glands. Tiny ducts run from the many tiny glands, connect together, and end in the nipple.
  
  
• These ducts are where 80% of breast cancers occur. This condition is called infiltrating ductal cancer.
  
  
• Cancer developing in the lobules is termed infiltrating lobular cancer. About 10-15% of breast cancers are of this type.
  
  
• Another type of breast cancer is inflammatory breast cancer.

Precancerous changes, called in situ (in see-too) changes, also are common.

• In situ is Latin for “in place” or “in site” and means that the changes haven’t spread from where they started.
  
  
• When these in situ changes occur in the ducts, they are called ductal carcinoma in situ (DCIS).
  
  
• When they happen in the lobules, they are called lobular carcinoma in situ (LCIS).
  
  
• DCIS is frequently diagnosed on routine mammography.

The most serious cancers are metastatic cancers.

• Metastasis means that the cancer has spread from the place where it started into other tissues.
  
  
• The most common place for breast cancer to metastasize is into the lymph nodes under the arm or above the collarbone on the same side as the cancer.
  
  
• Other common sites of breast cancer metastasis are the brain, the bones, and the liver.

About 50% of women who develop breast cancer have no risk factors other than age and sex.

• Sex is the biggest risk because breast cancer occurs mostly in women.
  
  
• Age is another critical factor. Breast cancer may occur at any age, though the risk of breast cancer increases with age.
  
  
• The average woman at age 30 years has 1 chance in 280 of developing breast cancer in the next 10 years. This chance increases to 1 in 70 for a woman aged 40 years, and to 1 in 40 at age 50 years. A 60-year-old woman has a 1 in 30 chance of developing breast cancer in the next 10 years.

Genetic causes

Family history has long been known to be a risk factor for breast cancer. The risk is highest if the affected relative developed breast cancer at a young age or if she is a close relative such as a mother, sister, daughter, or aunt.

There is great interest in genes linked to breast cancer.

• BRCA1 is an abnormal gene that, when inherited, markedly increases the risk of breast cancer to a lifetime risk of almost 85%. Women with this abnormal gene also have an increased likelihood of developing ovarian cancer. Women who have the BRCA1 gene tend to develop breast cancer at an early age.
  
  
• A second abnormal gene, BRCA2, increases the risk of developing breast cancer but not ovarian cancer.
  
  
• Testing for these genes is expensive and frequently not covered by insurance. In addition, women who test positive may have trouble getting or keeping health insurance.
  
  
• The issues around testing are complicated, and women who are interested in testing should discuss this with their health care providers.

Hormonal causes

Hormonal influences play a role in the development of breast cancer.

• Women who start their periods at an early age or experience a late menopause have a higher risk of developing breast cancer.
  
  
• Conversely, being older at your first menstrual period and early menopause tend to protect one from breast cancer.
  
  
• Having a child before age 30 years may provide some protection, and having no children may increase your risk for developing breast cancer.
  
  
• Oral contraceptives have not been shown to increase or decrease a woman's the lifetime risk of breast cancer.
  
  
• A large study conducted by the Women's Health Initiative showed an increased risk of breast cancer in postmenopausal women who were on a combination of estrogen and progesterone for several years. Therefore, women who are considering hormone therapy for menopausal symptoms need to discuss the risk versus the benefit with their health care providers.

Dietary causes

Breast cancer seems to occur more frequently in countries with high dietary intake of fat.

• This link is thought to be an environmental influence rather than genetic. For example, Japanese women, at low risk for breast cancer while in Japan, increase their risk of developing breast cancer after coming to the United States.
  
  
• Several studies comparing groups of women with high- and low-fat diets, however, have failed to show a difference in breast cancer rates.

Benign breast disease

Fibrocystic breast changes are very common.

• Fibrocystic breasts are lumpy with some thickened tissue and are frequently associated with breast discomfort, especially right before your menstrual period.
  
  
• This condition does not lead to breast cancer.
  
  
• However, certain types of benign breast changes, such as those diagnosed on biopsy as proliferative or hyperplastic, do predispose women to the later development of breast cancer.

Environmental causes

Radiation treatment seems to increase the likelihood of developing breast cancer but only after a long delay. For example, women who received radiation therapy to the upper body for treatment of Hodgkin disease before age 15 years have a significantly higher rate of breast cancer than the general population.

Early breast cancer has no symptoms. It is not painful.

Most breast cancer is discovered before symptoms are present, either by finding an abnormality on mammography or feeling a breast lump. You may also notice a lump under your arm or above your collarbone that does not go away. Other possible symptoms are breast discharge, nipple inversion, or changes in the skin overlying the breast.

• Most breast lumps are not cancerous. All breast lumps, however, need to be evaluated by a doctor.
  
  
• Breast discharge is a common problem and is rarely a symptom of cancer. Discharge is most concerning if it is from only 1 breast or if it is bloody. In any case, all breast discharge should be evaluated.
  
  
• Nipple inversion is a common variant of normal nipples, but nipple inversion that is a new development can be of concern.
  
  
• Changes in the skin of the breast include redness, changes in texture, and puckering. These changes are usually caused by skin diseases but occasionally can be associated with breast cancer.

Breast cancer develops over months or years. Once it is identified, however, a certain sense of urgency is felt about the treatment, because breast cancer is much more difficult to treat as it spreads from the breast.

You should see your health care provider if you experience any of the following:

• Finding a breast lump
  
  
• Finding a lump in your armpit or above your collarbone that does not go away in a week or so
  
  
• Developing breast discharge
  
  
• Noticing new nipple inversion or skin changes over the breast

Redness or swelling in the breast may suggest an infection of the breast.

• You should see your health care provider within the next 24 hours because infection should be treated promptly.
  
  
• If you have redness, swelling, or severe pain in the breast and are unable to reach your health care provider, a trip to the nearest emergency department is warranted.

If an abnormality is found on your mammogram, you should see your health care provider right away to make a plan for further evaluation.

Diagnosis of breast cancer usually comprises several steps, including examination of the breast, mammography, possibly ultrasonography, and finally biopsy. Biopsy is the only definitive way to diagnose breast cancer.

Examination of the breast

• A complete breast examination includes visual inspection and careful palpation (feeling) of the breasts, the armpits, and the areas around your collarbone.
  
  
• During that exam, your health care provider may palpate a lump or just feel a thickening.

Mammography

• Mammograms are x-rays of the breast that may help define the nature of a lump.
  
  
• Usually, it is possible to tell from the mammogram whether a lump in the breast is breast cancer, but no test is 100% reliable. Mammograms are thought to miss as many as 10-15% of breast cancers.
  
  
• A false-positive mammogram is one that suggests malignancy (cancer) when no malignancy is found on biopsy.
  
  
• A false-negative mammogram is one that appears normal when in fact cancer is present.
  
  
• A mammogram alone may not be enough to evaluate a lump. Your health care provider may want additional tests.
  
  
• All breast lumps need to be clearly defined as benign or should be biopsied.

Ultrasound

• Ultrasound of the breast may be done in addition to the mammogram.
  
  
• Ultrasound waves create a "picture" of the inside of the breast.
  
  
• It can demonstrate whether a mass is filled with fluid (cystic) or solid. Cancers are usually solid, but many cysts are benign.
  
  
• Ultrasound might also be used to guide a biopsy or the removal of fluid.

Biopsy

• The only way to diagnose breast cancer with certainty is to biopsy the tissue in question. Biopsy means to take a very small piece of tissue from the body for examination and testing. A number of biopsy techniques are available.
  
  
• Fine-needle aspiration consists of placing a needle into the breast and sucking out some cells to be examined by the pathologist. This technique is used most commonly when a fluid-filled mass is identified and cancer is not likely.
  
  
• Core-needle biopsy is performed with a special needle that takes a small piece of tissue for examination. Usually the needle is directed by ultrasound or by mammogram.
  
  
• Occasionally, if the mass is easily felt, cells may be removed with a needle without additional guidance. This technique is being used more and more because it is less invasive than surgical biopsy. It obtains only a sample of tissue rather than removing an entire lump.
  
  
• Surgical biopsy is done by making an incision in the breast and removing the piece of tissue. Certain techniques allow removal of the entire lump.
  
  
• In sentinel node biopsy, a radioactive substance is injected into the area of the tumor. The path of the substance is then followed as it travels to the lymph nodes. The first node reached is the sentinel node. This node is considered most important to biopsy when looking for spreading of the tumor.

Regardless of how the biopsy is taken, the tissue will be reviewed by a pathologist. These are physicians who are specially trained in diagnosing diseases by looking at cells and tissues under a microscope.

If the cells are cancerous, the person will undergo an operation for removal of the tumor.

• Additional tissue around the tumor will also be removed to check for microscopic (invisible) spread of the cancer.
  
  
• How much tissue has to be removed depends on the individual situation.
  
  
• Sometimes the whole breast is removed (mastectomy).
  
  
• Typically, some lymph nodes under the arm are removed and tested for cancer.

After these tissues are removed, the cancer is staged. Staging is a classification that implies which treatment is best and also the prognosis for recovery.

• Staging in breast cancer is based on the size of the tumor, which parts of the breast are involved, how many and which lymph nodes are affected, and whether the cancer has metastasized to another part of the body.
  
  
• Cancers may be referred to as invasive if they have spread to other tissues. Those that do not spread to other tissues are called noninvasive. Carcinoma in situ is a noninvasive cancer.

Breast cancer is staged from 0 to IV.

• Stage 0 is noninvasive breast cancer, that is, carcinoma in situ with no affected lymph nodes or metastasis. This is the most favorable stage of breast cancer.
  
  
• Stage I is breast cancer that is less than three quarters of an inch in diameter and has not spread from the breast.
  
  
• Stage II is breast cancer that is fairly small in size but has spread to lymph nodes in the armpit OR cancer that is somewhat larger but has not spread to the lymph nodes.
  
  
• Stage III is breast cancer of a larger size (greater than 2 inches in diameter), with greater lymph node involvement, or of the inflammatory type.
  
  
• Stage IV is metastatic breast cancer: a tumor of any size or type that has metastasized to another part of the body. This is the least favorable stage.

Most specialists test the tumor for hormone receptors. Receptors are sites on the surface of tumor cells that bind to estrogen or progesterone. In general, the more receptors, the more sensitive the tumor will be to hormone therapy.

|Self-Care at Home|

Until the late stages of breast cancer, when care is confined to easing suffering and increasing comfort, home care for breast cancer is not appropriate. All women with breast lumps should be seen by a doctor, and breast cancer should be treated by cancer specialists (oncologists).

|Medical Treatment|

In this disease, patient preference plays a major role in decisions regarding treatment. Treatment depends on a large number of factors, including the type of breast cancer, the hormone receptor status of the tumor, the stage of the tumor, the size of the breast, and the person's general health, age, and menstrual status (has or has not been through menopause).

Radiation therapy is used to kill tumor cells if there are any left after surgery.

• Radiation is a local treatment and therefore works only on tumor cells that are directly in its beam.
  
  
• Radiation is used most often in people who have undergone conservative surgery such as lumpectomy. Conservative surgery is designed to leave as much of the breast tissue in place as possible.
  
  
• Radiation therapy is usually given 5 days a week over 5-6 weeks. Each treatment takes only a few minutes.
  
  
• Radiation therapy is painless and has relatively few side effects. However, it can irritate the skin or cause a burn similar to a bad sunburn in the area.

Chemotherapy consists of the administration of medications that kill cancer cells or stop them from growing.

• Most chemotherapy agents are given through an IV line, but some are given as pills.
  
  
• Chemotherapy is usually given in "cycles." Each cycle includes a period of intensive treatment lasting a few days or weeks followed by a few weeks of recovery. Most people with breast cancer receive at least 2, more often 4, cycles of chemotherapy to begin with. Tests are then repeated to see what effect the therapy has had on the cancer.
  
  
• Chemotherapy differs from radiation in that it treats the entire body and thus may find stray tumor cells that may have migrated from the breast area.
  
  
• The side effects of chemotherapy are well known. Side effects depend on which drugs are used, but some that are common to many of these drugs include loss of hair, nausea and vomiting, loss of appetite, fatigue, and low blood cell counts, which may cause you to be more susceptible to infections, to feel sick and tired, or to bleed more easily than usual.

In breast cancer, 3 different chemotherapy strategies are used.

• Adjuvant chemotherapy is given to people who have had curative treatment for their breast cancer, such as surgery and radiation. It is given to decrease the possibility of the disease returning.
  
  
• Presurgical chemotherapy is given to shrink a large tumor and/or to kill stray cancers cells. This increases the chance that surgery will get rid of the cancer completely.
  
  
• Regular chemotherapy is routinely administered to people with breast cancer that has spread beyond the confines of the breast or local area.

Hormonal therapy may be given because breast cancers (especially those that have ample estrogen or progesterone receptors) are frequently sensitive to changes in hormones.

• In some cases, it is beneficial to suppress a woman's natural hormones with drugs; in others, it is beneficial to add hormones.
  
  
• At present, tamoxifen (Nolvadex) is the most commonly prescribed hormone treatment. It is used both for breast cancer prevention and for treatment. In the very elderly, tamoxifen alone has minimal side effects and may dramatically improve advanced breast cancer.
  
  
• Another agent, fulvestrant (Faslodex) has recently been approved in the United States. It is indicated for the treatment of hormone receptor–positive metastatic breast cancer in postmenopausal women with disease progression following antiestrogen therapy (for example, treatment with tamoxifen).

Monoclonal antibodies are antibodies against proteins in or around a cancer cell. Antibodies recognize an "invader"—in this case, a cancer cell—and attack it.

• Monoclonal antibody therapy for breast cancer is currently being investigated.
  
  
• Trastuzumab (Herceptin) is an antibody against the HER-2 protein, a protein responsible for cancer cell growth in many women with breast cancer (about 30% of breast cancers).
  
  
• It is under active study in women whose tumors have certain characteristics that suggest they may respond.

|Surgery|

Surgery is the mainstay of therapy for breast cancer. The choice as to which type of surgery is based on a number of factors, including the size and location of the tumor, the type of tumor, and the person's overall health and personal wishes. Breast-sparing surgery is often possible.

• Lumpectomy involves removal of the cancerous tissue and a surrounding area of normal tissue. Generally the lymph nodes in the armpit are sampled at the same time. This is not considered curative and should almost always be done in association with other therapy such as radiation therapy with or without chemotherapy or hormonal therapy.
  
  
• Simple mastectomy removes the entire breast but no other structures. If the cancer is invasive, this surgery alone will not cure it. It is a common treatment for DCIS, a noninvasive type of breast cancer.
  
  
• Modified radical mastectomy removes the breast and the axillary (underarm) lymph nodes but does not remove the underlying muscle of the chest wall. Although additional chemotherapy or hormonal therapy is almost always offered, surgery alone is considered adequate to control the disease if it has not metastasized.
  
  
• Radical mastectomy involves removal of the breast and the underlying chest wall muscles, as well as the underarm contents. This surgery is no longer done because current therapies are less disfiguring and have fewer complications.

|Follow-up|

People who have been diagnosed with breast cancer need careful follow-up care for life.

• Initial follow-up care after treatment is usually every 3-6 months for the first 2-3 years.
  
  
• This most often includes careful breast examination, yearly mammography, blood work, and, possibly, a chest x-ray.
  
  
• Other tests, such as bone scans or CT scans, are done as needed.

Any woman with a mother, daughter, or sister with breast cancer should be screened for breast cancer at least yearly.

|Prevention|

In women who are genetically at high risk for the development of breast cancer, tamoxifen has been shown to significantly decrease the incidence of the disease.

• Side effects should be carefully discussed with your health care provider prior to embarking on therapy.
  
  
• A second drug, raloxifene (Evista), which is now being used for the treatment of osteoporosis, also appears to prevent breast cancer. It is under active study.

Obesity after menopause and excessive alcohol intake may increase the risk of breast cancer slightly. Physically active women may have a lower risk.

Occasionally, a woman at very high risk for development of breast cancer will decide to have a preventive or prophylactic mastectomy to avoid developing breast cancer.

The most important risk factors for the development of breast cancer are sex, age, and genetics.

• Because most women can do nothing about these risks, regular screening is recommended in order to prevent death from breast cancer.
  
  
• Regular screening should include breast self-examination, clinical breast examination, and mammography.

Breast self-examination (BSE): All women 20 years and older are strongly encouraged to examine their breasts once a month.

• For women who are menstruating, the best time for examination is immediately after the monthly period.
  
  
• For women who are not menstruating or who are extremely irregular, picking a certain date each month seems to work best.
  
  
• Instruction in the technique of breast self-examination can be obtained from your health care provider or from any one of several organizations interested in breast cancer.

Clinical breast examination: The American Cancer Society recommends a breast examination by a trained health care provider once every 3 years starting at age 20 years, and then yearly after age 40 years.

Mammograms are recommended every 1-2 years starting at age 40 years.

|Outlook|

Prognosis is frequently defined in terms of 5-year survival rate, that is, the percentage of people alive 5 years after diagnosis. Although several factors affect prognosis, the stage of the disease is most important.

• People with disease confined to the breast have a 5-year survival rate of 97%.
  
  
• Those with involvement of regional lymph nodes have a 5-year survival rate of 75-85%.
  
  
• Those with stage III disease with more extensive local or lymph disease have a 5-year survival rate of approximately 50%.
  
  
• When the disease has already spread from the immediate area or metastasized, the 5-year survival rate is 20%.
  
  
• Older people with breast cancer (those older than 65 years) have a better prognosis than younger ones.

It is helpful to remember that survival rates are calculated for groups of people with the same disease. Within the group, survival rates vary considerably. Breast cancer, even metastatic breast cancer, is a highly treatable disease.

|Support Groups and Counseling|

American Cancer Society
(800) ACS-2345

National Cancer Institute
Cancer Information Service
Toll-free - (800) 4–CANCER (1–800–422–6237)
TTY (for deaf and hard-of-hearing callers) - (800) 332–8615

|Web Links|

American Cancer Society 

National Cancer Institute, NCI Online  - Cancer information specialists offer online assistance through the LiveHelp link

Y-Me National Breast Cancer Organization

Susan G. Komen Breast Cancer Foundation

Breast Cancer Week

Advances in Oncology

BRCA1, BRCA2, breast adenocarcinoma, breast carcinoma, cancer of the breast, ductal carcinoma in situ, DCIS, genetic testing, lobular carcinoma in situ, LCIS, mammary carcinoma, mammogram, mammography, metastasis, metastatic breast cancer, ovarian cancer, cancer of the ovary, breast cancer

Author: Mary Buechler, MD, Consulting Staff, Department of Emergency Medicine, Deaconess-Glover Hospital.

Coauthor(s): Elizabeth Buechler, MD, Director of Obstetrics and Gynecology, Clinical Instructor, Department of Obstetrics and Gynecology, Harvard Medical School.

Editors: Jerry Balentine, DO, Professor of Emergency Medicine, New York College of Osteopathic Medicine; Medical Director, Saint Barnabas Hospital; Francisco Talavera, PharmD, PhD, Senior Pharmacy Editor, ; Lee P Shulman, MD, Professor of Obstetrics and Gynecology, Head, Section of Reproductive Genetics, Feinberg School of Medicine, Northwestern University, Chicago, Illinois.