Cancer is caused by cells mutating (changing from normal to abnormal) and growing out of control. It is believed that both our environment and our genes play a role in whether or not we develop cancer. We can only estimate the risk of women with certain characteristics or "risk factors" and compare them to women without those risks. Both the risk factors that have been proven and factors that are believed to be potential risk factors are listed below.

• Proven Risk Factors
• Potential Risk Factors
• African-American Women Risk Factors
• Male Breast Cancer and Risk Factors
• Genetic Testing

Over 70 percent of breast cancers occur in women who have no identifiable risk factor other than age. Age is the most important factor in the risk for breast cancer. The older a woman is, the greater her chance of getting breast cancer. No woman is too old to need regular mammograms. Currently 62 percent of breast cancers are discovered at an early, "localized" stage. The five-year survival rate after treatment for early-stage breast cancer is 96 percent.

• Female
• Over the age of 50
• Family history, especially mother, sister, daughter or other first degree relative
• Two or more close relatives, such as cousins, with a history of breast cancer (especially if diagnosed at a young age)
  
• Nullparity (no children)
• Early menarche (first period) before age 12
• First full-term pregnancy after age 30
• Late menopause (after age 50)
• Genetic test fiindings associated with breast cancer
• Exposure to high dose ionization radiation (for cancer, acne, thyroid)
• Previous breast cancer in the same or opposite breast
• History of abnormal breast cells on previous biopsy
• Diagnosis of a breast condition that may predispose a woman to breast cancer (i.e., atypical hyperplasia)

One or more of the following conditions also increases risk for breast cancer:

• Tall stature and heavy frame
  
• Obesity (apple shaped women)
• Obesity after menopause
  
• Women who give birth after 30 years of age (slightly increased risk)
• Alcohol intake over nine drinks per week
• History of high alcohol intake before age 30
• Exposure to prolonged use of high dose estrogen
• High fat diet, low fiber, low antioxidants, low zinc, low selenium
• Lack of exercise, especially before age 40
• Environmental hazard exposure

In addition, women who had chest or thyroid irradiation at age 30 or younger are at higher risk for breast cancer during their lives. Chest irradiation is used to treat such conditions as Hodgkin's disease. These women need to be closely watched for breast cancer.

Factors that increase cancer risk do not by themselves cause cancer. A woman with one or more is not certain to or even likely to develop breast cancer. Even women with no other risk factors except a strong family history of breast cancer, for example, get cancer only 25 percent of the time.

On the other hand, not having any of the known risk factors does not mean that a woman is "safe." Most women who develop breast cancer do not have a strong family history of breast cancer or fall into any special higher risk category.

U.S. studies suggest that African-American women get cancer at about the same rate as Caucasian women. African-American women are slightly more likely to develop breast cancer before age 50. They are somewhat less likely to develop breast cancer after age 50.

African-American women are more than twice as likely to die from breast cancer. A number of studies have tried to determine why. Researchers have compared the tumors of African-American women to the tumors of other groups of women. Overall, no basic differences have been discovered.

African-American women have fewer mammograms than Caucasian women. By the time the cancer is found, it is more likely to have spread to other parts of the body. When breast cancer is more advanced, it is more difficult to treat. Survival rates are lower.

African-American women who have regular mammograms have the same excellent chances as all other groups of women. Mammograms detect breast cancers at a much earlier stage than breast examinations alone. These early tumors can be treated more easily and are more likely to be cured.

Current breast cancer treatments appear just as helpful for African-American women as for Caucasian women.

Male breast cancer is rare. Many people do not know that men can get breast cancer. A man's risk of breast cancer increases with age. In the U.S., about 1,600 men are diagnosed with breast cancer per year. Another 400 die of breast cancer. Men can have the same types of breast cancer as women. However, 70 percent of male breast cancers are ductal carcinoma, making it the most common. Like women's breast cancer, men's breast cancer can be cured or controlled if it is detected early and treated promptly.

The first symptom men usually notice is a painless lump. Other symptoms might include nipple discharge (possibly bloody), nipple retraction and skin ulceration.

For a variety of reasons, men may not get early treatment for breast cancer. Men are unlikely to regularly examine their breasts. When men notice symptoms, they tend to delay seeing a physician. Men are usually somewhat older than women at the time of diagnosis (age 65 on average).

Diagnosis and treatment of men's breast cancer is similar to that for women's breast cancer. Surgical treatment may be followed by radiation and chemotherapy. Whether a patient will be given chemotherapy depends on individual factors, including age. This decision must be made on a case-by-case basis. Hormone therapy is another treatment option. Ablative hormone therapy, in which hormone glands are surgically removed, may be used in some cases.

Risk factors for male breast cancer include:

• Estrogen administration
• Hyperestrogenism-associated diseases (e.g., cirrhosis, Klinefelter's syndrome)
• Radiation exposure
• Testicular injury
• Mumps orchitis
• Family history of breast cancer (male or female)
• Families with the BRCA2 mutation on chromosome 13q

Genetic testing can determine if a woman has inherited mutations to the so-called "breast cancer genes" known as BRCA1 and BRCA2. Cedars-Sinai's GenRISKŪ Program provides genetic testing for breast cancer. These genes predispose her to breast and ovarian cancer, but only account for five to 10 percent of all breast cancers. Genetic counseling and testing may be considered for women with two or more first-degree relatives (mother, sister, daughter) with breast and/or ovarian cancer. Although a positive result on a genetic test indicates increased risk of developing breast cancer, it cannot predict with certainty that you will ever get the disease.

Similarly, a negative result is not a guarantee that you will not get breast cancer. It just means that if you do develop the disease, it is unlikely to be the inherited, familial type.