Breast cancer is the second most common cancer in women after skin cancer. Mammograms can detect breast cancer early, possibly before it has spread. Explore the links on this page to learn more about breast cancer prevention, screening, treatment, statistics, research, clinical trials, and more.

Breast Cancer Treatment

  • Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
  • A family history of breast cancer and other factors increase the risk of breast cancer.
  • Breast cancer is sometimes caused by inherited gene mutations (changes).
  • The use of certain medicines and other factors decrease the risk of breast cancer.
  • Signs of breast cancer include a lump or change in the breast.
  • Tests that examine the breasts are used to detect (find) and diagnose breast cancer.
  • If cancer is found, tests are done to study the cancer cells.
  • Certain factors affect prognosis (chance of recovery) and treatment options.

The breast is made up of lobes and ducts. Each breast has 15 to 20 sections called lobes. Each lobe has many smaller sections called lobules. Lobules end in dozens of tiny bulbs that can make milk. The lobes, lobules, and bulbs are linked by thin tubes called ducts.

Each breast also has blood vessels and lymph vessels. The lymph vessels carry an almost colorless, watery fluid called lymph. Lymph vessels carry lymph between lymph nodes. Lymph nodes are small, bean-shaped structures found throughout the body. They filter lymph and store white blood cells that help fight infection and disease. Groups of lymph nodes are found near the breast in the axilla (under the arm), above the collarbone, and in the chest.

The most common type of breast cancer is ductal carcinoma, which begins in the cells of the ducts. Cancer that begins in the lobes or lobules is called lobular carcinoma and is more often found in both breasts than are other types of breast cancer. Inflammatory breast cancer is an uncommon type of breast cancer in which the breast is warm, red, and swollen.

Male Breast Cancer Treatment

  • Male breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
  • A family history of breast cancer and other factors can increase a man’s risk of breast cancer.
  • Male breast cancer is sometimes caused by inherited gene mutations (changes).
  • Men with breast cancer usually have lumps that can be felt.
  • Tests that examine the breasts are used to detect (find) and diagnose breast cancer in men.
  • If cancer is found, tests are done to study the cancer cells.
  • Survival for men with breast cancer is similar to survival for women with breast cancer.
  • Certain factors affect prognosis (chance of recovery) and treatment options.

Breast cancer may occur in men. Breast cancer may occur in men at any age, but it usually occurs in men between 60 and 70 years of age. Male breast cancer makes up less than 1% of all cases of breast cancer.

The following types of breast cancer are found in men:

  • Infiltrating ductal carcinoma: Cancer that has spread beyond the cells lining ducts in the breast. This is the most common type of breast cancer in men.
  • Ductal carcinoma in situ: Abnormal cells that are found in the lining of a duct; also called intraductal carcinoma.
  • Inflammatory breast cancer: A type of cancer in which the breast looks red and swollen and feels warm.
  • Paget disease of the nipple: A tumor that has grown from ducts beneath the nipple onto the surface of the nipple.

Lobular carcinoma in situ (abnormal cells found in one of the lobes or sections of the breast), which sometimes occurs in women, has not been seen in men.

Childhood Breast Cancer Treatment

Fibroadenomas are benign tumors. Rarely, these tumors become large phyllodes tumors (cancer) and begin to grow quickly. If a benign tumor begins to grow quickly, a fine-needle aspiration (FNA) biopsy or an excisional biopsy will be done. The tissues removed during the biopsy will be viewed under a microscope by a pathologist to check for signs of cancer.

Breast Cancer Treatment During Pregnancy

Breast cancer occurs about once in every 3,000 pregnancies. It occurs most often in women aged 32 to 38 years. Because many women are choosing to delay having children, it is likely that the number of new cases of breast cancer during pregnancy will increase.

The breasts usually get larger, tender, or lumpy in women who are pregnant, nursing, or have just given birth. This occurs because of normal hormone changes that take place during pregnancy. These changes can make small lumps difficult to detect. The breasts may also become denser. It is more difficult to detect breast cancer in women with dense breasts using mammography. Because these breast changes can delay diagnosis, breast cancer is often found at a later stage in these women.

Breast Cancer Prevention

  • Breast cancer is a disease in which malignant (cancer) cells form in the tissues of the breast.
  • Breast cancer is the second most common type of cancer in American women.

Breast Cancer Screening

See the following PDQ summaries for more information about breast cancer:

  • Breast Cancer Prevention
  • Breast Cancer Treatment (Adult)
  • Male Breast Cancer Treatment
  • Genetics of Breast and Gynecologic Cancers

Women in the United States get breast cancer more than any other type of cancer except for skin cancer.

Breast cancer is more likely to occur as a woman ages. It occurs more often in white women than in black women, but black women die from breast cancer more often than white women.

Breast cancer rarely occurs in men. Because men with breast cancer usually have a lump that can be felt, screening tests are not likely to be helpful.

What is Cancer?

  • Cancer can start almost anywhere in the human body, which is made up of trillions of cells. Normally, human cells grow and divide to form new cells as the body needs them. When cells grow old or become damaged, they die, and new cells take their place.

  • Cancer prevention is action taken to lower the risk of getting cancer. This can include maintaining a healthy lifestyle, avoiding exposure to known cancer-causing substances, and taking medicines or vaccines that can prevent cancer from developing.

  • Cancer can cause many different symptoms. Most often these symptoms are not caused by cancer, but by benign tumors or other problems. If you have symptoms that last for a couple of weeks, your doctor will do a physical exam and order tests or other procedures to find out what is causing your symptoms.