In the United States, breast cancer is the most common non-skin cancer and the second leading cause of cancer-related death (after lung cancer) in women. Breast cancer is a malignant tumor that grows in one or both of the breasts. Breast cancer usually develops in the ducts or lobules, also know as the milk-producing areas of the breast.
An estimated 207,090 women and 1,970 men will be diagnosed with invasive breast cancer in 2010, and 40,230 (39,840 women, 390 men) will die of the disease (an additional 54,010 will develop non-invasive ductal carcinoma in situ, which means only in the milk ducts). Although African-American women have a slightly lower incidence of breast cancer after age 40 than Caucasian women, they have a slightly higher incidence rate of breast cancer before age 40. However, African-American women are more likely to die from breast cancer at every age.
If found early and treated before it spreads, the five-year survival rate for breast cancer is 98 percent for localized disease. Regular screening for breast cancer increases the likelihood of early diagnosis and survival.
- Every 2 minutes, there is a new breast cancer diagnosis.
- Every 14 minutes, a life is lost to the disease.
- Over 40,000 people will die this year; about 400 of them will be men.
- 85% of all diagnoses have no family history.
- 1 in 8 women will be diagnosed with breast cancer.
- Breast cancer is the leading cause of death in women between ages 40 and 55.
- A family history of breast cancer (risk increases with diagnoses in several close relatives or diagnoses before age 50).
- A family history of ovarian cancer.
- Genetic mutations (BRCA-1, BRCA-2 or others).
- Increasing age, with most breast cancer diagnosed in women over 40.
- Menstrual periods before age 12 or menopause after age 55.
- Obesity or sedentary lifestyle.
- Hormone replacement therapy with estrogen and progesterone.
- Exposure of breasts to previous radiation therapy.
- Previous breast cancer in one breast.
Risk Reduction and Early Detection
- If you have babies, breastfeed them.
- If you drink alcohol, limit your drinking to one drink a day if you are a woman and two drinks a day if you are a man.
- Be physically active and exercise regularly.
- Maintain a healthy body weight.
- In your 20s and 30s, have a clinical breast exam (CBE) by a health care professional every three years.
- Beginning at age 40, have an annual CBE.
- At age 40, begin annual screening mammography.
- If you are at high risk, talk to your health care professional about beginning to have screening mammograms at a younger age.
- If you are at very high risk, you may also have annual MRI (magnetic resonance imaging) exams.
- Ask your health care professional about other ways to reduce risk.
- If you have a family history of breast cancer, discuss genetic testing with a genetics counselor.
Breast self-exam is one way that you can get to know what is normal for your breasts. If you notice changes, see your health care professional right away.
Don't wait for symptoms to appear. Get screened according to guidelines. If you do notice any of the following symptoms, talk to your health care professional.
- A lump, mass or thickening in the breast
- A lump in the underarm area
- Change in the size or shape of a breast
- Nipple pain, tenderness or discharge, including bleeding
- Nipple turned inward or inverted
- Change in sin color and texture: dimpling, puckering or redness
- Breast that feels warm or swollen
Therapy depends on the type and the stage of the breast cancer.
- The most common treatment is surgery to remove the cancer itself (lumpectomy) combined with radiation. In about 20% of cases, the removal of the breast (mastectomy) is needed.
- Other therapies - chemotherapy or hormone therapy - may be used alone or in combination before or after surgery.
Types of Breast Cancer
There are several different types of breast cancer that can be divided into two main categories - noninvasive cancers and invasive cancers. Noninvasive cancer may also be called "carcinoma in situ." Noninvasive breast cancers are confined to the ducts or lobules and they do not spread to surrounding tissues. The two types of noninvasive breast cancers are ductal carcinoma in situ (referred to as DCIS) and lobular carcinoma in situ (referred to as LCIS).
It is known that hormones in a woman's body, such as estrogen and progesterone, can play a role in the development of breast cancer. In breast cancer, estrogen causes a doubling of cancer cells every 36 hours. The growing tumor needs to increase its blood supply to provide food and oxygen. Progesterone seems to cause stromal cells (the woman's own cells send out signals for more blood supply to feed the tumor).
- Non-invasive breast cancer: The majority of non-invasive breast cancers are DCIS. In DCIS, the cancer cells are found only in the milk duct of the breast. If DCIS is not treated, it may progress to invasive cancer.
- In LCIS, the abnormal cells are found only in the lobules of the breast. Unlike DCIS, LCIS is not considered to be a cancer. It is more like a warning sign of increased risk of developing an invasive breast cancer in the same or opposite breast. While LCIS is a risk factor for invasive cancer, it doesn't actually develop into invasive breast cancer in many women.
- Invasive breast cancer: Invasive or infiltrating breast cancers penetrate through normal breast tissue (such as the ducts and lobules) and invade surrounding areas. They are more serious than noninvasive cancers because they can spread to other parts of the body, such as the bones, liver, lungs and brain.
- There are several kinds of invasive breast cancers. The most common type is invasive ductal carcinoma, which appears in the ducts and accounts for about 80 percent of all breast cancer cases. There are differences in the various types of invasive breast cancer, but the treatment options are similar for all of them.
Not all breast cancers are alike. There are different stages of breast cancer based on the size of the tumor and whether the cancer has spread. For doctor and patient, knowing the stage of breast cancer is the most important factor in choosing among treatment options. Doctors use the physical exam, biopsy, and other tests to determine breast cancer stage.
Stages of Breast Cancer
The most common system used to describe the stages of breast cancer is the AJCC/TNM (American Joint Committee on Cancer/Tumor-Nodes-Metastases) system. This system takes into account the tumor size and spread, whether the cancer has spread to the lymph nodes, and whether it has spread to distant organs (metastasis).
All of this information is then combined in a process called stage grouping. The stage is expresed as a Roman numeral. After stage 0 (carcinoma in situ), the other stages ae I through IV (1-4). Some of the stages are further subdivided using the letters A, B, and C. In general, the lower the number, the less the cancer has spread. A higher number, such as stage IV (4), means a more advanced cancer.
These are the stages of breast cancer:
Stage 0 - Stage 0 is carcinoma in situ, early stage cancer that is confined to the ducts or the lobules, depending on where it started. It has not gone into the tissues in the breast nor spread to other organs of the body.
- Ductal carcinoma in situ (DCIS): This is the most common type of noninvasive breast cancer, when abnormal cells are in the lining of a duct. DCIS is also called intraductal carcinoma. DCIS sometimes become invasive cancer if not treated.
- Lobular carcinoma in situ (LCIS): This condition begins in the milk-making glands but does not go through the wall of the lobules. LCIS seldom becomes invasive cancer; however, having LCIS in one breast increases the risk of cancer for both breasts.
Stage I - Stage I is an early stage of invasive breast cancer. In Stage I, cancer cells have not spread beyond the breast and the tumor is no more than 2 centimeters (three-quarters of an inch) across.
Stage II - Stage II is one of the following:
- The tumor in the breast is no more than 2 centimeters (three-quarters of an inch) across. The cancer has spread to the lymph nodes under the arm.
- The tumor is between 2 and 5 centimeters (three-quarters of an inch to 2 inches). The cancer may have spread to the lymph nodes under the arm.
- The tumor is larger than 5 centimeters (2 inches). The cancer has not spread to the lymph nodes under the arm.
Stage III- Stage III may be a large tumor, but the cancer has not spread beyond the breast and nearby lymph nodes. It is locally advanced cancer.
- Stage IIIA - Stage IIIA is one of the following:
- The tumor in the breast is smaller than 5 centimeters (2 inches). The cancer has spread to underarm lymph nodes that are attached to each other or to other structures.
- The tumor is more than 5 centimeters across. The cancer has spread to the underarm lymph nodes.
- Stage IIIB- Stage IIIB is one of the following:
- The tumor has grown into the chest wall or the skin of the breast.
- The cancer has spread to lymph nodes behind the breastbone.
- Inflammatory breast cancer is a rare type of Stage IIIB breast cancer. The breast looks red and swollen because cancer cells block the lymph vessels in the skin of the breast.
- Stage IIIC- Stage IIIC is a tumor of any size. It has spread in one of the following ways:
- The cancer has spread to the lymph nodes behind the breastbone and under the arm.
- The cancer has spread to the lymph nodes under or above the collarbone.
Stage IV - Stage IV is distant metastic cancer. The cancer has spread to other parts of the body.
Recurrent cancer- Recurrent cancer is cancer that has come back (recurred) after a period of time when it could not be detected. It may recur locally in the breast or chest wall as another primary cancer, or it may recur in any other part of the body, such as the bone, liver or lungs, which is generally referred to as metastatic cancer.