
Breast cancer is a disease that forms in tissues of the breast, usually the ducts (tubes that carry milk to the nipple) and lobules (glands that make milk). It occurs in both men and women, although male breast cancer is rare.
The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes, which have many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can produce milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.
Each breast also has blood vessels and lymph vessels. The lymph vessels carry an almost colorless fluid called lymph. Lymph vessels lead to organs called lymph nodes. Lymph nodes are small bean-shaped structures that are found throughout the body. They filter substances in lymph and help fight infection and disease. Clusters of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.
The most common type of breast cancer is ductal carcinoma, which begins in the cells of the ducts. Cancer that begins in the lobes or lobules is called lobular carcinoma and is more often found in both breasts than are other types of breast cancer. Inflammatory breast cancer is an uncommon type of breast cancer in which the breast is warm, red, and swollen.
Age and health history can affect the risk of developing breast cancer.
Anything that increases your chance of getting a disease is called a risk factor.
Risk factors for breast cancer include the following:
Older age.
Menstruating at an early age.
Older age at first birth or never having given birth.
A personal history of breast cancer or benign (noncancer) breast disease. A mother or sister with breast cancer.
Treatment with radiation therapy to the breast/chest.
Breast tissue that is dense on a mammogram.
Taking hormones such as estrogen and progesterone.
Drinking alcoholic beverages.
Being white.
Breast cancer is sometimes caused by inherited gene mutations (changes). The genes in cells carry the hereditary information that is received from a person's parents. Hereditary breast cancer makes up approximately 5% to 10% of all breast cancer. Some altered genes related to breast cancer are more common in certain ethnic groups.
Women who have an altered gene related to breast cancer and who have had breast cancer in one breast have an increased risk of developing breast cancer in the other breast. These women also have an increased risk of developing ovarian cancer, and may have an increased risk of developing other cancers.
Men who have an altered gene related to breast cancer also have an increased risk of developing this disease. Tests have been developed that can detect altered genes. These genetic tests are sometimes done for members of families with a high risk of cancer.
Tests that examine the breasts are used to detect (find) and diagnose breast cancer. A doctor should be seen if changes in the breast are noticed.
The following tests and procedures may be used:
Biopsy: The removal of cells or tissues so they can be viewed under a microscope by a pathologist to check for signs of cancer. If a lump in the breast is found, the doctor may need to cut out a small piece of the lump.
Four types of biopsies are as follows:
Excisional biopsy: The removal of an entire lump or suspicious tissue.
Incisional biopsy: The removal of part of a lump or suspicious tissue.
Core biopsy: The removal of part of a lump or suspicious tissue using a wide needle.
Needle biopsy or fine needle aspiration biopsy: The removal of part of a lump, suspicious tissue, or fluid, using a thin needle.
Estrogen and progesterone receptor test: A test to measure the amount of estrogen and progesterone (hormones) receptors in cancer tissue. If cancer is found in the breast, tissue from the tumor is examined in the laboratory to find out whether estrogen and progesterone could affect the way cancer grows. The test results show whether hormone therapy may stop the cancer from growing.
Mammogram: An x-ray of the breast.
If breast cancer has been diagnosed, then additional tests are conducted to determine if cancer cells have spread throughout the breast or to other parts of the body. This process is called staging and is used to determine the stage of the cancer. It is very important to know the stage of the cancer to plan for the correct treatment.
Cancer spreads throughout the body in three different ways. These include through the tissue, through the lymph system or through the blood. When cancer cells break away from the original tumor and travel to other parts of the body, this is called metastasis. If breast cancer spreads to the bones, it is known as metastatic breast cancer and not bone cancer.
Stages of Breast Cancer:
Stage 0 also known as carcinoma in situ. There are two types of breast cancer in situ - Ductal carcinoma in situ (DCIS) is when abnormal cells are found in the lining of a breast duct. Ductal carcinoma can be noninvasive or invasive. Lobular carcinoma in situ (LCIS) is when abnormal cells are found in the lobules of the breast. Lobular carcinoma is usually not invasive but it does increase the risk of breast cancer in either breast.
Stage 1 - the cancer has formed and the tumor is less than 2 cm (smaller than a single peanut) in size and has not spread outside the breast.
Stage 2A - no tumor is found in the breast, but cancer is located in the axillary lymph nodes under the arm; OR the tumor is 2 cm or smaller and has spread axillary lymph nodes; OR the tumor is larger than 2 cm but not larger than 5 cm (size of a lime) and has not spread to the axillary nodes.
Stage 2B - the tumor is either larger than 2 cm but smaller than 5 cm and has not spread to the axillary lymph nodes; OR the tumor is larger than 5 cm but has not spread to the axillary lymph nodes.
Stage 3A - no tumor is found in the breast but cancer is found in the axillary lymph nodes that are attached to each other or the cancer may be in the lymph nodes near the breastbone; OR the tumor is larger than 2 cm but smaller than 5 cm. Cancer has spread to the axillary lymph nodes or the cancer may be in the lymph nodes near the breastbone; OR the tumor is larger than 5 cm and the cancer has spread to the axillary lymph nodes or to lymph nodes near the breastbone.
Stage 3B - the tumor may be any size and the cancer has spread to the chest wall or the skin of the breast and may have spread to the axillary lymph nodes that may be attached or the cancer may have spread to lymph nodes near the backbone.
Cancer that has spread to the skin of the breast is know as inflammatory breast cancer.
Stage 3C - there may be no evidence of cancer in the breast or the tumor may be any size and may have spread to the chest wall or the skin of the breast. In addition, cancer has spread to the lymph nodes above or below the collarbone; AND may have spread to the axillary lymph nodes or to lymph nodes near the breastbone.
Stage 3C breast cancer is either operable or inoperable. In operable stage 3C, the cancer is found in 10 or more axillary lymph nodes; OR is found in lymph nodes below the collarbone; OR is found in any axillary lymph nodes near the breastbone.
Inoperable stage 3C breast cancer has spread to the lymph nodes above the collar bone.
Stage 4 - the breast cancer has spread to other organs throughout the body, most often the lungs, bones, liver or brains.
Breast Cancer Treatments
There are five types of breast cancer treatments that are usually recommended. These include chemotherapy, hormone therapy, radiation therapy, surgery, and targeted therapy.
Chemotherapy - is a treatment for cancer that uses drugs to stop the growth of the cancer cells by either killing them or keeping them from dividing. The way that chemotherapy is given depends on the stage of the breast cancer.
Hormome Therapy - is a treatment for breast cancer that removes or blocks hormones to keep the cancer cells from growing.
Radiation Therapy - is a treatment for cancer that uses x-rays or other forms of radiation to kill breast cancer cells or keep them from growing. The two types of radiation therapy can be administered either outside the body (external) or inside the body (internal).
Surgery - most breast cancer patients usually have surgery to remove the cancer from the breast. Axillary lymph nodes from under the arm are usually removed to see if they contain cancer cells.
There are several types of breast cancer operations that are used to remove the cancer depending on the severity of the breast cancer.
Breast conserving surgery - involves two different procedures that remove the breast cancer but not the breast. These include the lumpectomy and partial masectomy.
A lumpectomy removes the tumor and a small amount of normal tissue around the lump.
The partial masectomy removes the part of the breast that has cancer and some of the normal tissue around it.
Total Mastectomy - this removes the whole breast that has cancer and is also called a simple mastectomy. Axillary lymph nodes under the arm may also be removed for biopsy.
Modified Radical Mastectomy - this surgery is used to remove the entire breast that has breast cancer and some of the lymph nodes under the arm, the lining over the chest muscle, and sometimes a portion of the muscles of the chest wall.
Radical Mastectomy - is surgery that removes the breast with cancer, chest wall muscles under the breast, and all of the axillary lymph nodes under the arm. This procedure is also known as the Halsted radical mastectomy.
Targeted Therapy - is a cancer treatment that uses drugs or antibodies to identify and attack breast cancer cells without harming normal cells. These type of treatments are still being closely studied to determine their effectiveness.