Breast cancer is the most common malignancy in women and the second leading cause of cancer death, exceeded only by lung cancer in 1985. One woman in eight who lives to age 85 will develop breast cancer at some time during her life.
At present there are over 2 million women living in the United States who have been treated for breast cancer. About 41,000 women will die from the disease. The chance of dying from breast cancer is about 1 in 33. However, the rate of death from breast cancer is going down. This decline is probably the result of early detection and improved treatment.
Breast cancer is not just a woman’s disease. The American Cancer Society estimates that 1600 men develop the disease yearly and about 400 may die from the disease.
Breast cancer risk is higher among those who have a mother, aunt, sister, or grandmother who had breast cancer before age 50. If only a mother or sister had breast cancer, your risk doubles. Having two first-degree relatives who were diagnosed increases your risk up to five times the average.
Although it is not known exactly what causes breast cancer; sometimes the culprit is a hereditary mutation in one of two genes, called BRCA1 and BRCA2. These genes normally protect against the disease by producing proteins that guard against abnormal cell growth, but for women with the mutation, the lifetime risk of developing breast cancer can increase up to 80 percent, compared with 13 percent among the general population. In effect, more than 25 percent of women with breast cancer have a family history of the disease.
For women without a family history of breast cancer, the risks are harder to identify. It is known that the hormone estrogen feeds many breast cancers, and several factors – diet, excess weight, and alcohol consumption – can raise the body’s estrogen levels.
Early signs of breast cancer include the following:
– A lump which is usually single, firm and most often painless is detected.
– An area of the skin on the breast or underarm is swollen and has an unusual appearance.
– Veins on the skin surface become more prominent on one breast.
– The affected breast nipple becomes inverted, develops a rash, changes in skin texture, or has a discharge other than breast milk.
– A depression is found in an area of the breast surface.
Types and Stages of Breast Cancer
There are many different varieties of breast cancer. Some are fast-growing and unpredictable, while others develop more slowly and steady. Some are stimulated by estrogen levels in the body; some result from mutation in one of the two previously mentioned genes – BRCA1 and BRCA2.
Ductal Carcinoma In-Situ (DCIS): Generally divided into comedo (blackhead), in which the cut surface of the tumor shows extrusion of dead and necrotic tumor cells similar to a blackhead, and non-comedo types. DCIS is early breast cancer that is confined to the inside of the ductal system. The distinction between comedo and non-comedo types is important, as comedocarcinoma in-situ generally behaves more aggressively and may show areas of micro-invasion through the ductal wall into surrounding tissue.
Infiltrating Ductal: This is the most common type of breast cancer, representing 78 percent of all malignancies. On mammography, these lesions can appear in two different shapes — stellate (star- like) or well circumscribed (rounded). The stellate lesions generally have a poorer prognosis.
Medullary Carcinoma: This malignancy comprises 15 percent of breast cancers. These lesions are generally well circumscribed and may be difficult to distinguish from fibroadenoma by mammography or sonography. With this type of breast cancer, prognostic indicators estrogen and progesterone receptor are negative 90 percent of the time. Medullary carcinoma usually has a better prognosis than other types of breast cancer.
Infiltrating Lobular: Representing 15 percent of breast cancers, these lesions generally appear in the upper outer quadrant of the breast as a subtle thickening and are difficult to diagnose by mammography. Infiltrating lobular can involve both breasts (bilateral). Microscopically, these tumors exhibit a linear array of cells and grow around the ducts and lobules.
Tubular Carcinoma: This is described as orderly or well-differentiated carcinoma of the breast. These lesions make up about 2 percent of breast cancers. They have a favorable prognosis with nearly a 95 percent 10-year survival rate.
Mucinous Carcinoma: Represents 1-2 percent of carcinoma of the breast and has a favorable prognosis. These lesions are usually well circumscribed (rounded).
Inflammatory Breast Cancer: This is a particularly aggressive type of breast cancer that is usually evidenced by changes in the skin of the breast including redness (erythema), thickening of the skin and prominence of the hair follicles resembling an orange peel. The diagnosis is made by a skin biopsy, which reveals tumors in the lymphatic and vascular channels about 50 percent of the time.
Stages of Breast Cancer
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 (ductal) or a lobule (lobular) and whether it has invaded nearby tissues in the breast (invasive).
When cancer is found, special lab tests of the tissue are usually done to learn more about the cancer. For example, hormone (estrogen and progesterone) receptor tests can help determine whether hormones help the cancer to grow. If test results show that hormones do affect the growth of the cancer (a positive test result), the cancer is likely to respond to hormonal therapy. This therapy deprives the cancer cells of estrogen.
Other tests are sometimes done to help predict whether the cancer is likely to progress. For example, x-rays and other lab tests are done. Sometimes a sample of breast tissue is checked for a gene, known as the human epidermal growth factor receptor-2 (HER-2 gene) that is associated with a higher risk that the breast cancer will recur. Special exams of the bones, liver, or lungs are done because breast cancer may spread to these areas.
A woman’s treatment options depend on a number of factors. These factors include her age and menopausal status; her general health; the size and location of the tumor and the stage of the cancer; the results of lab tests; and the size of her breast. Certain features of the tumor cells, such as whether they depend on hormones to grow are also considered.
In most cases, the most important factor is the stage of the disease. The stage is based on the size of the tumor and whether the cancer has spread. The following are brief descriptions of the stages of breast cancer and the treatments most often used for each stage. Other treatments may sometimes be appropriate.
Stage 0 is sometimes called non-invasive carcinoma or carcinoma in situ. Lobular carcinoma in situ (LCIS) refers to abnormal cells in the lining of a lobule. These abnormal cells seldom become invasive cancer. However, they are an indicator of an increased risk of developing breast cancer in both breasts. The treatment for LCIS is a drug called tamoxifen, which can reduce the risk of developing breast cancer. A person who is affected may choose not to have treatment, but to monitor the situation by having regular checkups. And occasionally, the decision is made to have surgery to remove both breasts to try to prevent cancer from developing. In most cases, removal of underarm lymph nodes is not necessary.
Ductal carcinoma in situ (DCIS) refers to abnormal cells in the lining of a duct. DCIS is also called intraductal carcinoma. The abnormal cells have not spread beyond the duct to invade the surrounding breast tissue. However, women with DCIS are at an increased risk of getting invasive breast cancer. Some women with DCIS have breast-sparing surgery followed by radiation therapy. Alternatively, they may choose to have a mastectomy, with or without breast reconstruction (plastic surgery) to rebuild the breast. Underarm lymph nodes are not usually removed. Also, women with DCIS may want to talk with their doctor about tamoxifen to reduce the risk of developing invasive breast cancer.
Stage I and II
Stage I and stage II are early stages of breast cancer in which the cancer has spread beyond the lobe or duct and invaded nearby tissue.
Stage I means that the tumor is about one inch across and cancer cells have not spread beyond the breast.
Stage II means one of the following:
The tumor in the breast is less than 1 inch across and the cancer has spread to the lymph nodes under the arm.
The tumor is between 1 and 2 inches (with or without spread to the lymph nodes under the arm).
The tumor is larger than 2 inches but has not spread to the lymph nodes under the arm.
The treatment options for early stage breast cancer are breast-sparing surgery followed by radiation therapy to the breast, and mastectomy, with or without breast reconstruction to rebuild the breast. These approaches are equally effective in treating early stage breast cancer. (Sometimes radiation therapy is also given after mastectomy.)
The choice of breast-sparing surgery or mastectomy depends mostly on the size and location of the tumor, the size of the breast, certain features of the cancer, and how the person feels about preserving the breast. With either approach, lymph nodes under the arm usually are removed.
Chemotherapy and/or hormonal therapy after primary treatment with surgery or surgery and radiation therapy are recommended for stage I and most frequently with stage II breast cancer. This added treatment is called adjuvant therapy. Systemic therapy sometimes given to shrink the tumor before surgeries called neoadjuvant therapy. This is given to try to destroy any remaining cancer cells and prevent the cancer from recurring, or coming back, in the breast or elsewhere.
Stage III is also called locally advanced cancer. In this stage, the tumor in the breast may exhibit the following:
More than 2 inches across and the cancer has spread to the underarm lymph nodes.
The cancer is extensive in the underarm lymph nodes.
The cancer is spreading to lymph nodes near the breastbone or to other tissues near the breast.
Inflammatory breast cancer is a type of locally advanced breast cancer. In this type of cancer, the breast looks red and swollen (or inflamed) because cancer cells block the lymph vessels in the skin of the breast.
Patients with stage III breast cancer usually have both local treatment to remove or destroy the cancer in the breast and systemic treatment to stop the disease from spreading. The local treatment may be surgery and/or radiation therapy to the breast and underarm. The systemic treatment may be chemotherapy, hormonal therapy, or both. Systemic therapy may be given before local therapy to shrink the tumor or afterward to prevent the disease from recurring in the breast or elsewhere.
Stage IV is metastatic cancer. The cancer has spread beyond the breast and underarm lymph nodes to other parts of the body.
The treatments for stage IV breast cancer are chemotherapy and/or hormonal therapy to destroy cancer cells and control the disease. Patients may have surgery or radiation therapy to control the cancer in the breast. Radiation may also be useful to control tumors in other parts of the body.
Recurrent cancer means the disease has returned in spite of the initial treatment. Even when a tumor in the breast seems to have been completely removed or destroyed, the disease sometimes returns because undetected cancer cells remained somewhere in the body after treatment.
Most recurrences appear within the first 2 or 3 years after treatment, but breast cancer can recur many years later.
Cancer that returns only in the area of the surgery is called a local recurrence. If the disease returns in another part of the body, the recurrence is called metastatic breast cancer. The patient may have one type of treatment or a combination of treatments for recurrent cancer.
For more information, see “Nine Ways to Reduce Breast Cancer Risk” on this site.
Sources: National Cancer Institute; Centers for Disease Control