Breast cancer is the most common cause of cancer in women and the second most common cause of cancer death in women in the world. While the majority of new breast cancers are diagnosed as a result of an abnormality seen on a mammogram, a lump or change in consistency of the breast tissue can also be a warning sign of the disease. Heightened awareness of breast cancer risk in thepast decades has led to an increase in the number of women undergoing mammography for screening, leading to detection of cancers in earlier stages and a resultant improvement in survival rates. Still, breast cancer is the most common cause of death in women between the ages of 45 and 55. Although breast cancer in women is a common form of cancer, male breast cancer does occur and accounts for about1% of all cancer deaths in men.
Research has yielded much information about the causes of breast cancers, and it is now believed that genetic and/or hormonal factors are the primary risk factors for breast cancer. Staging systems have been developed to allow doctors to characterize the extent to which a particular cancer has spread and to make decisions concerning treatment options. Breastcancer treatment depends upon many factors, including thee type of cancer and the extent to which it has spread. Treatment options for breast cancer may involve surgery (removal of the cancer alone or, in some cases, mastectomy), radiation therapy, hormonal therapy, and/or chemotherapy.
With advances in screening, diagnosis, and treatment, the death rate for breast cancer has declined by about 20%over the past decade, and research is ongoing to develop even more effective screening and treatment programs.
HOW IS THE BREAST DESIGNED?
The breasts sit on the chest muscles that cover the ribs. Each breast is made of 15 to 20 lobes. Lobes contain many smaller lobules. Lobules contain groups of tiny glands that can produce milk. Milk flows from the lobules through thin tubes called ducts tothe nipple. The nipple is in the center of a dark area of skin called the areola. Fat fills the spaces between the lobules and ducts.
The breasts also contain lymph vessels. These vessels lead to small, round organs called lymph nodes. Groups of lymph nodes are near the breast in the axilla (underarm), above the collarbone, in the chest behind the breastbone, and in many other parts of thebody. The lymph nodes trap bacteria, cancer cells, or other harmful substances.
WHAT IS THE CANCER PROCESS?
Cancer begins in cells, the building blocks that make up tissues. Tissues make up the organs of the body.
Normally, cells grow and divide to form new cells as the body needs them. When cells grow old, they die, and new cells take their place.
Sometimes, this orderly processgoes wrong. New cells form when the body does not need them, and old cells do not die when they should. These extra cells can form a mass of tissue called a growth or tumor.
Tumors can be benign or malignant:
Benign tumors are not cancer:
✓ Benign tumors are rarely life-threatening.
✓ Generally, benign tumors can be removed. They usually do not grow back.
✓ Cells from benign tumorsdo not invade the tissues around them.
✓ Cells from benign tumors do not spread to other parts of the body.
Malignant tumors are cancer:
✓ Malignant tumors are generally more serious than benign tumors. They may be life-threatening.
✓ Malignant tumors often can be removed. But sometimes they grow back.
✓ Cells from malignant tumors can invade and damage nearbytissues and organs.
Cells from malignant tumors can spread (metastasize) to other parts of the body. Cancer cells spread by breaking away from the original (primary) tumor and entering the bloodstream or lymphatic system. The cells invade other organs and form new tumors that damage these organs. The spread of cancer is called metastasis.
When breast cancer cells spread, the cancer cells are...