Breast Cancer

Breast cancer is a malignant tumor that develops from cells of the human breast. Without medical treatment, this malignant tumor may invade surrounding tissues or spread (metastasize) to distant areas of the body, preventing normal function of vital organs and damaging essential systems, eventually leading to death. Over the course of a lifetime, one in eight women will be diagnosed with breast cancer. Each year in the United States, about 190,000 new cases of breast cancer are diagnosed and an estimated 40,000 women will die from the disease.


Because breast cancer is easiest to treat if detected in its early stages, women are encouraged to become familiar and aware of their breasts and its changes. Conducting a monthly self exam of the breasts can alert a woman to an abnormal change that may require a doctor’s examination. In addition, because women over the ago of 40 have a higher risk of developing the disease, their health care professionals usually require an annual mammogram.

The first signs of breast cancer are usually noted as a difference in the way the breast looks or feels. These differences include lumps or a thickening or the skin, as well as tenderness of the nipple. It is possible the nipple may be turned slightly inward or the skin of the breast may appear scaly or red. Often these signs are not linked to cancer, but tests must be conducted to be sure.

Tests such as mammograms and ultrasounds can be used in many cases to rule out cancer. In the event the results of these imaging tests are unclear, the next step is to have a biopsy. During the biopsy, cells or tissue are removed from the suspected cancerous area then examined to see if they contain cancer cells. If cancer is confirmed at this point, other tests are performed to determine if the cancer has spread to other areas of the body and if it will respond well to certain treatments.


Treatments for breast cancer can be divided into two general types: local – used to remove or destroy cancer cells in a particular area – and systemic – used to destroy or control cancer cells throughout the body. Local treatments include surgery and radiation therapy. Systemic treatments include chemotherapy – using drugs to kill cancer cells – hormone therapy – using drugs to prevent hormones from encouraging the growth of cancer cells – and targeted therapies such as Herceptin – using drugs to attack specific pathways or molecular agents in order to inhibit cancer growth.

Doctors design treatment plans using the methods described above in the combination best suited to address the type and growth rate of each individual’s breast cancer. An example of such a plan would be surgery followed by chemotherapy and hormone therapy. Therapies work best when the cancer is detected in its early stages and has a good chance of being completely destroyed.

Risk Factors

As with most cancers, age is a major risk factor. In fact, growing older is the biggest risk for breast cancer. 77% of new cases and 84% of breast cancer deaths occur in women aged 50 and older. More than 80% of breast cancer cases occur in women over 50.

Genetic Factors and Family History of Breast Cancer
Some families appear to have a genetic tendency for breast cancer. The exact mechanism is still not clear, but research suggests that breast cancer is caused by the gradual accumulation of genetically damaged cells over time. Two variant genes have been found that appear to account for this, which researchers have named BRCA1 and BRCA2. The genes p53 and BARD1 also appear to be a factor, as well as BRCA3 and Noey2 (the latter is a disease inherited only from the father's side of the family).

Breast cancer is the most common cancer to affect women. The risk of breast cancer is clearly related to hormonal influences, but the exact mechanism of how these affect the disease is still not totally clear. High levels of estrogen during a woman's reproductive years, especially when they are not interrupted by the hormonal changes of pregnancy, appear to increase the chances that genetically damaged cells will grow and cause cancer. Women carrying mutated BRCA1 and/or BRCA2 genes appear to have a "head start" in this process. Men can also get breast cancer, but it is much less common, accounting for less than 1% of all breast cancers.

Early Menstruation and Late Menopause
Women who started menstrual periods early (before age 12) or went through menopause late (after age 55) are at higher risk. Each is directly related to the body having produced estrogen for a longer period of time. Also, women who have never had children or who had them only after the age of 30 have an increased risk. Again, this is related to the body producing estrogen uninterrupted for a longer period of time.

Oral Contraceptives (birth control pills)
In the past, oral contraceptives contained high levels of the hormones estrogen and progesterone, and use of these contraceptives showed a small link to an increased risk for breast cancer. Today’s birth control pills contain very low doses of estrogen and progesterone.

Hormone Replacement Therapy
Use of HRT for more than five years has been shown to slightly increase the risk of breast cancer; this risk increases with longer use.

Being overweight has shown to increase the risk, due to the increased production of estrogen.

Alcohol Consumption
Excessive alcohol use (more than 1-2 drinks a day) has been associated with an increased risk of breast cancer. This seems to be caused by the liver’s decreased ability to regulate blood estrogen levels.

Some studies have pointed to exposure to estrogen-like chemicals that are found in pesticides and other industrial products as a possible increased risk of breast cancer.

Women who took diethylstilbestrol (DES) to prevent miscarriage may have an increased risk of breast cancer.

People exposed to radiation, particularly during childhood, may face an increased risk for breast cancer in adulthood. Especially at risk are those that received chest irradiation for prior cancers.

Additional Risk Factors
Some studies show previous breast, uterine, ovarian, colon cancer, and a strong history of cancer in the family may increase the risk for breast cancer.

111 Forest Avenue 1R
Narberth PA 19072

" is a nonprofit organization dedicated to providing the most reliable, complete, and up-to-date information about breast cancer. Our mission is to help women and their loved ones make sense of the complex medical and personal information about breast cancer, so they can make the best decisions for their lives."

The Susan G. Komen Breast Cancer Foundation
5005 LBJ Freeway, Suite 250
Dallas, TX 75244
Telephone: 972-855-1600
Helpline: 1.800 I'M AWARE®

"For more than 20 years, the Susan G. Komen Breast Cancer Foundation has been a global leader in the fight against breast cancer through its support of innovative research and community-based outreach programs. Working through a network of U.S. and international Affiliates and events like the Komen Race for the Cure®, the Komen Foundation is fighting to eradicate breast cancer as a life-threatening disease by funding research grants and supporting education, screening and treatment projects in communities around the world."

National Breast Cancer Foundation, Inc.
2600 Network Blvd.
Suite 300
Frisco, Texas 75034

"The National Breast Cancer Foundation mission is to save lives by increasing awareness of breast cancer through education and by providing mammograms for those in need."