About breast cancer

What should people know about breast cancer?

Breast cancer is one of the most common cancers among women.  It is estimated that one in eight women will develop breast cancer during her life.

Men also get breast cancer, but it is very rare.

Who gets breast cancer?

All women can get breast cancer. However, breast cancer is more common among older women. The risk for getting breast cancer increases with age. More than three-quarters of women who get breast cancer are over the age of 50. White women are more likely to get breast cancer than Black women, but, once they have the disease, Black women are more likely to die from it. Asian and Hispanic women are less likely to get breast cancer than White women or Black women. Also, women of higher socioeconomic status (those whose family informers are above average) are more likely to get breast cancer. Scientists believe this may be related to having their first child at an older age, fewer pregnancies, diet and possible other characteristics shared by women in higher income groups.

What factors increase risk for developing breast cancer?

At this time, the causes of breast cancer are not well understood. However, scientists agree that certain factors increase a person's risk of developing this disease. These risk factors include:

Age. As women get older, their risk of developing breast cancer increases.

Family history. Women whose close relatives (parents, brothers/sisters, children) have had breast cancer (especially at an early age) are more likely to get breast cancer.

Genetics. Women with certain changes in breast cancer related genes (BRCA1 and BRCA2) are at higher risk for getting breast cancer. About 5% to 10% of breast cancers are believed to be due to genetic factors.

Personal history. Women who have had cancer in one breast are more likely to develop it in the other breast or in remaining breast tissue. Women who have a history of certain types of benign (non-cancerous) tumors and cysts in their breast are more likely to develop breast cancer. Also women with dense breast tissue are at increased risk for the disease.

Hormonal factors. Women who start their menstrual periods at a young age, start menopause at a late age, have their first child later in life, or have not had full-term pregnancies may have an increased risk of developing breast cancer.

Not breastfeeding. Not breastfeeding increases a woman's chance of developing breast cancer.

Hormone use. Long-term use of hormone replacement therapy (estrogen and progesterone combined) increases the risk of developing breast cancer. However, women who have not used hormone replacement therapy in the past 10 years may not be at increased risk.

Personal behaviors. Some personal behaviors have been shown to increase risk for getting breast cancer. These include excessive alcohol use and not getting enough exercise. Also, being overweight or obese increases the risk of breast cancer after menopause.

Ionizing Radiation. Exposure to high levels of ionizing radiation to the chest area early in life, such as radiation therapy for Hodgkin lymphoma, increases the risk of developing breast cancer.

What other risk factors for breast cancer are scientists studying?

Scientists are studying other possible personal risk factors for breast cancer including diet, smoking, exposure to second hand smoke, current or recent use of oral contraceptives (birth control pills), use of the synthetic estrogen diethylstilbestrol (DES) prior to the early 1970s to prevent miscarriage, exposure to estrogens and progestins in some personal care products and night-shift employment.

A number of chemicals are being studied as possible risk factors for breast cancer. These include various by-products of industrial processing, production and combustion, pesticides, metals, and solvents.

Additional research is needed to determine the role, if any, these factors may have in the development of breast cancer.

How else can I reduce my risk for cancer?

The following may help reduce the risk of developing cancer:

Choose a healthy diet to achieve and maintain a healthy weight. Eat more vegetables, fruits and whole grains and eat less red and processed (e.g., bacon, sausage, luncheon meats, hot dogs) meats. These actions may reduce the risk of developing many types of cancer and other diseases.o

Do not smoke. If you currently smoke, quit. Avoided exposure to second hand smoke. Talk with your health care provider about recommended screenings for other types of cancer.