Breast Cancer Description
Most kinds of cancer are named after the part of the body where the cancer first starts. Breast cancer begins in the breast
tissue. This information refers only to breast cancer in women. Men can also get breast cancer, although this is rare.
Background 
Inside the breasts are glands that produce andrelease milk after a woman has a baby. The glands that make the milk are
called lobules and the tubes that connect them to the nipple are called ducts. The breast itself is made up of lobules; ducts; and fatty,
connective, and lymphatic tissue.
There are several types of breast tumors. Most are benign; that is, they are not cancer. These lumps are often caused by
fibrocystic changes. Cysts are fluid-filled sacs, and fibrosis refers to connective tissue or scar tissue formation. Fibrocystic changes can cause
breast swelling and pain. The breasts may feel lumpy and sometimes there is a clear or slightly cloudy nipple discharge. Benign breast tumors are abnormal
growths, but they do not spread outside of the breast and they are not life-threatening.
How it spreads
When breast cancer spreads outside the breast, cancer cells often are found in the lymph nodes under the arm. Cancer cells may spread beyond the
breast such as to other lymph nodes, the bones, liver, or lungs. (Although it is not common, some patients whose underarm lymph nodes are clear of breast
cancer may still have cancer cells which have spread to other parts of the body.)
When breast cancer spreads, it is called metastatic breast cancer even though it is found in another part of the body. For example, breast cancer that has spread to the bones is called metastatic breast cancer, not bone cancer.
Common Types
Inflammatory Breast Cancer
Inflammatory breast cancer is a rare, but very serious, aggressive type of breast cancer. The breast may look red and feel warm. You may see ridges,
welts, or hives on your breast; or the skin may look wrinkled. It is sometimes misdiagnosed as a simple infection.
Recurrent Breast Cancer
Recurrent disease means that the cancer has come back (recurred) after it has been treated. It may come back in the breast, in the soft tissues of the
chest (the chest wall), or in another part of the body.
(Tumor size is usually reported in metric measurement: 1centimeter=approximately 1/2 inch.)
Breast Cancer in situ--DCIS and LCIS
Many breast cancers being found are very early cancers known as breast cancer in situ or noninvasive cancer. Most of these cancers are found by mammography.
These very early cell changes may become invasive breast cancer. Two types of breast cancer in situ are:
- DCIS (ductal carcinoma in situ), which means that abnormal cells are found only in the lining of a milk duct
of the breast. These abnormal cells have not spread outside the duct. They have not spread within the breast, beyond the breast, to the lymph nodes
under the arm, or to other parts of the body. There are several types of DCIS. If not removed, some types may change over time and become invasive
cancers. Some may never become invasive cancers. (DCIS is sometimes called intraductal carcinoma.)
- LCIS (lobular carcinoma in situ), which means that abnormal cells are found in the lining of a milk lobule.
Although LCIS is not considered to be actually breast cancer at this noninvasive stage, it is a warning sign of increased risk of developing invasive
cancer. LCIS is sometimes found when a biopsy is done for another lump or unusually change that is found on a mammogram. Patients with LCIS
have a 25 percent chance of developing breast cancer in either breast during the next 25 years.
Microcalcifications are
very small specks of calcium that can?t be felt, but can be seen on a mammogram. They are formed by rapidly dividing cells. When they are clustered in one area of the breast, this could be an early sign of breast cancer in situ. About half of the breast cancers found by mammography appear as clusters of microcalcifications. The other half appear as lumps.
To be sure that you have a correct diagnosis if breast cancer in situ is detected, an experienced pathologist should
examine your biopsy slides. You may want to have your slides examined also by a second pathologist at a university hospital, cancer center, or breast clinic. This is important because it is sometimes difficult to make and accurate diagnosis. The pathologist needs to determine the types of cells that are present in the tissue sample, how fast the cells are changing, and whether it is likely to become invasive cancer. The diagnosis will help your doctor decide on the appropriate treatment from a wide range of choices. The decision could be to have frequent follow-up exams to watch the suspicious area, or surgery
to remove only the affected tissue, or surgery to remove one or both breasts. Surgery removing only the affected area is sometimes followed by radiation therapy to the breast.
Statistics
Breast cancer is the most frequently diagnosed cancer in women in the United States today, other than skin cancer. Even
though breast cancer is more common in older women, it also occurs in younger women and even in a small number of men.
Breast cancer is the most common cancer among women, other than skin cancer. It is the second leading cause of cancer death in women, after lung cancer. Breast cancer is the leading cause of cancer death among women aged 40 to 55.
The ACS estimates that there will be about 175,000 new cases of invasive breast cancer this year among women in the
United States and about 43,300 deaths from the disease.
About 50%-60% of women with certain genetic changes (mutations) will develop breast cancer by the age of 70. They also
have an increased risk of ovarian cancer. Genetic testing can tell if a woman has these mutated genes, but it cannot predict whether a woman will get breast cancer.
