Breast Cancer

Risk Factors You Cannot Change

• Getting older. The risk for breast cancer increases with age. Most breast cancers are diagnosed after age 50.
• Genetic mutations. Women who have inherited changes (mutations) to certain genes, such as BRCA1 and BRCA2, are at higher risk of breast and ovarian cancer.
• Reproductive history. Starting menstrual periods before age 12 and starting menopause after age 55 expose women to hormones longer, raising their risk of getting breast cancer.
• Having dense breasts. Dense breasts have more connective tissue than fatty tissue, which can sometimes make it hard to see tumors on a mammogram. Women with dense breasts are more likely to get breast cancer.
• Personal history of breast cancer or certain non-cancerous breast diseases. Women who have had breast cancer are more likely to get breast cancer a second time. Some non-cancerous breast diseases such as atypical hyperplasia or lobular carcinoma in situ are associated with a higher risk of getting breast cancer.
• Family history of breast or ovarian cancer. A woman’s risk for breast cancer is higher if she has a mother, sister, or daughter (first-degree relative) or multiple family members on either her mother’s or father’s side of the family who have had breast or ovarian cancer. Having a first-degree male relative with breast cancer also raises a woman’s risk.
• Previous treatment using radiation therapy. Women who had radiation therapy to the chest or breasts (for instance, treatment of Hodgkin’s lymphoma) before age 30 have a higher risk of getting breast cancer later in life.
• Exposure to the drug diethylstilbestrol (DES). DES was given to some pregnant women in the United States between 1940 and 1971 to prevent miscarriage. Women who took DES, or whose mothers took DES while pregnant with them, have a higher risk of getting breast cancer.

Risk Factors You Can Change

Being physically active can help lower your risk of getting breast cancer.

• Not being physically active. Women who are not physically active have a higher risk of getting breast cancer.
• Being overweight or having obesity after menopause. Older women who are overweight or have obesity have a higher risk of getting breast cancer than those at a healthy weight.
• Taking hormones. Some forms of hormone replacement therapy (those that include both estrogen and progesterone) taken during menopause can raise risk for breast cancer when taken for more than five years. Certain oral contraceptives (birth control pills) also have been found to raise breast cancer risk.
• Reproductive history. Having the first pregnancy after age 30, not breastfeeding, and never having a full-term pregnancy can raise breast cancer risk.
• Drinking alcohol. Studies show that a woman’s risk for breast cancer increases with the more alcohol she drinks.

Research suggests that other factors such as smoking, being exposed to chemicals that can cause cancer, and changes in other hormones due to night shift working also may increase breast cancer risk.

Although it is rare, men can get breast cancer. Learn about symptoms of breast cancer in men and things that may increase your risk.

Breast cancer is most often found in women, but men can get breast cancer too. About 1 out of every 100 breast cancers diagnosed in the United States is found in a man.

The most common kinds of breast cancer in men are the same kinds in women—

• Invasive ductal carcinoma. The cancer cells begin in the ducts and then grow outside the ducts into other parts of the breast tissue. Invasive cancer cells can also spread, or metastasize, to other parts of the body.
• Invasive lobular carcinoma. Cancer cells begin in the lobules and then spread from the lobules to the breast tissues that are close by. These invasive cancer cells can also spread to other parts of the body.
• Ductal carcinoma in situ (DCIS) is a breast disease that may lead to invasive breast cancer. The cancer cells are only in the lining of the ducts, and have not spread to other tissues in the breast.

What Are the Symptoms?

The most common symptoms of breast cancer in men are—

• A lump or swelling in the breast.
• Redness or flaky skin in the breast.
• Irritation or dimpling of breast skin.
• Nipple discharge.
• Pulling in of the nipple or pain in the nipple area.

These symptoms can happen with other conditions that are not cancer. If you have any symptoms or changes, see your doctor right away.

What Are the Risk Factors?

Several factors can increase a man’s chance of getting breast cancer. Having risk factors does not mean you will get breast cancer.

• Getting older. The risk for breast cancer increases with age. Most breast cancers are found after age 50.
• Genetic mutations. Inherited changes (mutations) in certain genes, such as BRCA1 and BRCA2, increase breast cancer risk.
• Family history of breast cancer. A man’s risk for breast cancer is higher if a close family member has had breast cancer.
• Radiation therapy treatment. Men who had radiation therapy to the chest have a higher risk of getting breast cancer.
• Hormone therapy treatment. Drugs containing estrogen (a hormone that helps develop and maintain female sex characteristics), which were used to treat prostate cancer in the past, increase men’s breast cancer risk.
• Klinefelter syndrome. Klinefelter syndrome is a rare genetic condition in which a male has an extra X chromosome. This can lead to the body making higher levels of estrogen and lower levels of androgens (hormones that help develop and maintain male sex characteristics).
• Certain conditions that affect the testicles. Injury to, swelling in, or surgery to remove the testicles can increase breast cancer risk.
• Liver disease. Cirrhosis (scarring) of the liver can lower androgen levels and raise estrogen levels in men, increasing the risk of breast cancer.
• Overweight and obesity. Older men who are overweight or have obesity have a higher risk of getting breast cancer than men at a normal weight.

What Can I Do to Reduce My Risk?

If several members of your family have had breast or ovarian cancer, or one of your family members has a known BRCA1 or BRCA2 mutation, share this information with your doctor. Your doctor may refer you for genetic counseling. In men, mutations in the BRCA1 and BRCA2 genes can increase the risk of breast cancer, high-grade prostate cancer, and pancreatic cancer.

If genetic testing shows that you have a BRCA1 or BRCA2 gene mutation, your doctor will explain what you should do to find cancer early, if you get it.

All men can lower their risk by keeping a healthy weight and being physically active.

*Data and information from the CDC: cdc.gov.