Breast Cancer

Breast cancer is the abnormal growth of malignant (cancerous) cells within the body’s breast tissue. Both men and women are at risk for breast cancer. However, the disease is far more prevalent in women with 1 in 8 women in the United States developing breast cancer during their lives1.

Credit: Arizona State University

What are the different types of breast cancer?

There are several types of breast cancer that affect the different cells of the breast. Read more about the types of breast cancer at:

What are the symptoms of breast cancer?

  • A change in how the breasts or nipples feel or look Nipple tenderness
  • A change in skin texture on the breast
  • A lump in the breast
  • Dimpling anywhere on the breast
  • Swelling or shrinkage of breast (especially if on one side only) Inverted, slightly inward, or red nipple
  • Clear or bloody nipple discharge

How is breast cancer diagnosed?

Mammograms use low-dose x-rays to examine a patient’s breasts. A mammography exam aids in the early detection and diagnosis of breast cancer in those with few or no symptoms of the disease.

Physical exams for breast cancer will focus on the breasts and nipples to check for lumps or areas of irregular texture and/or size. Lymph nodes under the armpit and above the collarbone will also be checked for swelling during this exam.

Imaging tests use x-rays, magnetic fields, or sound waves to create pictures of the inside of the body. For breast cancer, these tests will include mammograms, magnetic resonance imaging (MRI) scans, ultrasounds, ductograms, chest x-rays, bone scans, computed tomography (CT) scans, and positron emissions tomography (PET) scans.

Biopsies are the removal of a small sample of cells from the breast tissue and/or lymph nodes for microscopic examination to determine the presence of cancer.

Molecular tests are used to further examine a case of breast cancer to determine appropriate treatment plans. These tests include estrogen receptor (ER), progesterone receptor (PR), HER2, and Ki67 tests.

Blood tests are used to gather more information about a diagnosed case of breast cancer. These tests include complete blood counts (CBCs), serum chemistry tests, hepatitis tests, and blood tumor marker tests.

What are the stages of breast cancer?

The most common system used to describe the stages of breast cancer is the American Joint Committee on Cancer (AJCC) TNM system.

The TNM staging system is based on 3 key pieces of information:

  • T followed by a number from 0 to 4 describes the tumor's size and spread to the skin or to the chest wall under the breast. Higher T numbers mean a larger tumor and/or wider spread to tissues near the breast.
  • N followed by a number from 0 to 3 indicates whether the cancer has spread to lymph nodes near the breast and, if so, how many lymph nodes are affected.
  • M followed by a 0 or 1 indicates whether the cancer has spread to distant organs -- for example, the lungs or bones.

What are the treatments for breast cancer?

This breast cancer treatment information does not outline the particular treatment(s) a patient will receive. Rather, it provides general information about the typical treatments used to treat this cancer.

Primary treatment options:

Surgery is the most common form of treatment for breast cancer. During a surgical operation, the tumor and nearby tissue are removed. Surgical options for breast cancer include: lumpectomy, partial mastectomy, radical mastectomy, and reconstruction.

Chemotherapy is the use of drugs to kill cancer cells. For breast cancer, it is used before surgery (to shrink a tumor) and after surgery (to prevent recurrence). It is also used as the primary treatment to treat breast cancers that have metastasized.

Radiation therapy uses high-energy rays to kill cancer cells. Radiation therapies for breast cancer include: External beam radiation therapy and internal radiation therapy (also known as brachytherapy).

Secondary treatment options:

Hormone Therapies help destroy cancer cells by cutting off the supply of hormones, like estrogen, that make them grow. It is most often used after surgery to help prevent recurrence.

Targeted Therapies are drugs that prevent the growth of cancer cells and protect healthy breast cells from damage.

What are the risk factors of breast cancer?

  • Gender: Women are at 100 times greater risk for breast cancer compared to men.
  • Age: 2 out of 3 women are diagnosed after age 55.
  • Race: Caucasian women are most often diagnosed with breast cancer.
  • Family history: If a patient’s mother, sister, father or child has been diagnosed with breast or ovarian cancer, a person is at a higher risk of being diagnosed with breast cancer in the future. The risk of breast cancer increases if the relative was diagnosed before the age of 50.
  • History of other cancers: If a person has been diagnosed with breast cancer in one breast, he or she is at an increased risk of being diagnosed with breast cancer in the other breast.
  • Menstrual and reproductive history: Early menstruation (before age 12) late menopause (after 55) having your first child at an older age, or never having given birth may increase your risk for breast cancer.
  • Dense breast tissue: Having dense breast tissue can increase your risk for breast cancer and make lumps harder to detect.
  • Lack of physical activity: A sedentary lifestyle with little physical activity can increase your risk for breast cancer.
  • Poor diet: A diet high in saturated fat and lacking fruits and vegetables can increase your risk for breast cancer.
  • Being overweight or obese: This may increase your risk for breast cancer, especially if you’ve already gone through menopause.
  • Alcohol consumption: Frequent consumption of alcohol can increase your risk for breast cancer. The more alcohol you consume, the greater the risk.
  • Radiation to the chest: Having radiation therapy to the chest before the age of 30 can increase your risk for breast cancer.
  • Combined hormone replacement therapy (HRT): Taking combined hormone replacement therapy, as prescribed for menopause, can increase your risk for breast cancer. The longer you take HRT, the higher the risk for breast cancer.

How is breast cancer prevented?

  • Regular self-examinations for breast abnormalities may lead to early detection
  • Limiting alcohol consumption
  • Quitting or never starting to smoke tobacco
  • Maintaining a healthy weight, diet, and body composition
  • Breast feeding may play a role in prevention
  • Limiting the dose and duration of hormone therapy
  • Avoiding radiation exposure and pollution
Alexa Dessables , BS Student, Nursing , University of Arizona
Katie Messer , BS Student, Nursing , University of Arizona
Michael Principe, MA, Information Resources and Library Science , University of Arizona
Expert Reviewers: 
Cheryl Lacasse, MS, RN, OCN , Clinical Professor , College of Nursing, The University of Arizona
Works Cited: (2014). U.S. Breast Cancer Statistics.
Works Consulted: 
National Breast Cancer Foundation (2014). About Breast Cancer.
Susan G. Komen (2014). Understanding Breast Cancer.
American Cancer Society (2014). Breast Cancer.