Breast Cancer

Breast cancer is a potentially dangerous tumor that develops in the cells of the breast. Cancer cells sometimes spread from the breast to other parts of the body.

In the United States, breast cancer is a very common cancer among women, second only to skin cancer. Breast cancer also occurs in men, but much more rarely. Deaths from breast cancer have been reduced in recent years because more effective treatments are now available, and because these cancers are found earlier when they are easier to treat.

How Does Breast Cancer Start?

Humans are mammals, and all mammals have breasts, which are the organs that make milk to feed babies. In the breast are lobules (LOB-yools) that look like bunches of grapes. Channels, or ducts, from the lobules enable milk to flow to the nipple. The lobules and ducts are surrounded by fatty tissue and ligaments called stroma (STRO-ma).

Cancer in situ

Breast cancer begins when a single cell in a duct or lobule undergoes changes (mutations) that cause it to start growing out of control. At first, even though the cells are growing very rapidly, they stay within the duct or lobule. At this stage the cancer is called cancer in situ. Later, the cells may break out of the duct or lobule into the fat and surrounding tissue, where they continue to divide and multiply. Since a tumor needs nourishment to grow, it sends out signals in the form of proteins that cause new blood vessels to form and support it. Without a blood supply, a tumor will die.

Metastasis

Cancer cells may enter the bloodstream, where they may be killed by the immune system (the body's defense against disease). If they are not killed by the immune system, the cancer cells may travel to distant organs of the body, settle there, grow, and divide. This process of spread is called metastasis (me-TAS-ta-sis).

Breast cancer cells are most likely to find their way to the lungs, liver, and bones. Cancer is named for the place where it starts. So even when breast cancer travels to the lungs or the bones, it is still called breast cancer.

Who Gets Breast Cancer?

No one knows yet exactly what causes breast cancer to start. It is impossible to catch it from another person.

Can teenagers get breast cancer?

Breast cancer in teenagers is very rare. A girl whose breasts are developing may feel some discomfort from time to time. And once her periods start, she may retain water during the last part of her cycle, which can cause her breasts to ache. But these pains are a normal part of the body's functioning. They are not a sign of cancer.

BRCA1, BRCA2, and estrogen

Women who inherit some mutated genes from their parents are at higher risk of getting breast cancer. These genes, called BRCA1 and BRCA2, are involved in only a small fraction of breast cancer cases. Researchers suspect that natural substances called hormones, especially the female hormone estrogen, play a role in promoting some types of breast cancer.

Family history

A woman whose mother, sister, or daughter has had breast cancer has twice the risk of getting it as a woman with no family history of breast cancer. However, most women diagnosed with breast cancer do not (to their knowledge) have a family history of breast cancer. A woman who has already had breast cancer in one breast is at higher risk of getting it in the other breast.

Age

Age is also a risk factor. Older women have a higher risk of developing breast cancer. Another risk factor is early age for first menstrual period as well as late age for menopause. Women who have their first child after the age of 30, or who do not have any children, also have a higher risk.

Diet and life style

Rates of breast cancer vary around the world, and it appears these differences are related to diet or life style. For example, women in Asia have only one fifth to one tenth the risk of getting breast cancer as women in North America or Western Europe. But when Asian women move to Western countries, their risk increases to the same level as the local population. The reasons why are not clear.

What Happens When Women Have Breast Cancer?

Signs and symptoms

Usually, a woman will notice a painless lump in her breast. Or her doctor may feel the lump during a routine examination. The shape, color, or texture of the breast or nipple may change or the nipple may be tender or have a discharge. Sometimes cancers are found before symptoms occur. In these cases, routine or "screening" mammography (mam-MOG-ra-fee) (x-ray examination of the breasts) shows changes that indicate a possibility of cancer, which must be checked.

Diagnosis

If screening tests or a woman's symptoms suggest cancer, the doctor may request a biopsy (BY-op-see). In this procedure, a small amount of tissue is removed from the abnormal area of the breast and examined under a microscope. Most biopsies show that the woman does not have cancer. If the tissue is benign (be-NINE) (not cancer), no further treatment may be needed. But if the diagnosis is cancer, then the woman will want to learn about the disease and discuss her options for treatment with health professionals, her friends, and family.

Treatment

For tumors that do not appear to have spread, it may be possible to remove only the tumor and leave most of the breast. This is called a lumpectomy (lump-EK-to-mee). Sometimes, however, it may be necessary to perform a mastectomy (mas-TEK-to-mee), an operation that removes the breast. Whether mastectomy or lumpectomy is the best choice depends on the size and sometimes the kind of tumor.

Follow-up treatment may include radiation therapy and anti-cancer medication, called chemotherapy (kee-mo-THER-a-pee), to kill any remaining cancer cells and to prevent them from growing back. The choice of follow-up treatment depends on the kind of tumor and whether it appears to have spread to the lymph nodes ^* or other parts of the body.

Can Breast Cancer Be Prevented?

There is no sure way to prevent breast cancer. It may be possible for women to reduce their risk of breast cancer by not drinking too much alcohol, by eating a healthy diet, and by getting regular exercise. Because detecting cancer early improves the chance of treating it with a better outcome, or even curing it, women 40 and older should have a screening mammogram and a physical exam to check their breasts every year. Women aged 20 to 39 should have a breast exam every three years. And all women aged 20 and older should learn how to examine their own breasts and check them once a month.

Will There Ever Be a Way of Preventing Breast Cancer?

Because chemotherapy kills healthy cells as well as cancer cells, research efforts in the area of drug treatment are concentrating on drugs that do less damage to healthy cells than current treatments. Researchers also are studying how best to use the information from genetic tests for breast cancer genes to help a woman lower her risk of getting breast cancer.

Tamoxifen research

An effective treatment for many women with breast cancer is a drug called tamoxifen. This drug works against the hormones that stimulate the cells in the breast to grow and are believed to be a factor in many breast cancers. Tamoxifen is so effective that it was approved in the late 1990s for use by women who do not have breast cancer but who are at a high risk of getting it. Researchers are investigating similar drugs that do not have the side effects of tamoxifen and might be safe enough for healthy women at lower risk to use as a way of preventing breast cancer.

What Is It Like to Live with Breast
Cancer?

Treatment for breast cancer can be very unpleasant. Mastectomy is emotionally difficult, and some women, about 1 in 10, may get serious swelling in their arms as a result of the surgery. As with almost any kind of cancer, a person must learn to live with the fear that the cancer might return. Side effects of chemotherapy may make it impossible for a young woman with breast cancer to have children. Many women lose their hair temporarily. If the cancer has spread, it becomes important to recognize, plan for, and cope with the prospect of dying. And because breasts are a part of the body that we consider very personal and that a woman associates with many things she cherishes, including love and children, she may worry that the people closest to her see her differently. Many women who have had mastectomies are able to have breast reconstructive surgery, which can restore a more normal appearance following breast removal. Many women with breast cancer find support groups very helpful in dealing with the stresses of the illness. It is important for patients, friends, and family to remember that people are much more than the sum of their body parts. No one is to blame for cancer. Love and understanding may help to make even the most difficult situation bearable.