Breast Cancer

1. Breast Cancer Slideshow Pictures
2. Take the Breast Cancer Quiz
3. Disease Prevention in Women Slideshow Pictures

Medical Author:

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, Chief Medical Editor

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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Medical Editor:

Jerry R. Balentine, DO, FACEP

Jerry R. Balentine, DO, FACEP

Dr. Balentine received his undergraduate degree from McDaniel College in Westminster, Maryland. He attended medical school at the Philadelphia College of Osteopathic Medicine graduating in1983. He completed his internship at St. Joseph's Hospital in Philadelphia and his Emergency Medicine residency at Lincoln Medical and Mental Health Center in the Bronx, where he served as chief resident.

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• Breast Cancer Overview
• Breast Cancer Causes: Genes and Hormones
• More Breast Cancer Causes: Lifestyle, Diet, and Environment
• Breast Cancer Symptoms and Signs
• When to Seek Medical Care
• Breast Cancer Diagnosis
• Breast Cancer Treatment
• Self-Care at Home
• Medical Treatment: Radiation, Chemotherapy, and Hormonal Therapy
• More Medical Treatment: Monoclonal Antibodies and Surgery
• Follow-up
• Breast Cancer Prevention
• Breast Cancer Prognosis
• Breast Cancer Research
• Breast Cancer Support Groups and Counseling
• For More Information
• Synonyms and Keywords
• Authors and Editors
• Read more on Breast Cancer from Healthwise
• Breast Cancer FAQs
• Viewer Comments: Breast Cancer - How Was It Detected
• Viewer Comments: Breast Cancer - Symptoms

Breast cancer is cancer arising in breast tissue. Cancer is simply a group of abnormal cells that have abnormal growth patterns.

• Although breast cancer is primarily a disease of women, about 1% of breast cancers occur in men.
• Breast cancer is the most common type of cancer in women with the exception of nonmelanoma skin cancers. It is the second leading cause of death by cancer in women, following only lung cancer.
• In 2011, the American Cancer Society estimated that 230,480 new cases of invasive breast cancer would be diagnosed among women in the United States and that a further 57,650 new cases of in-situ (noninvasive) breast cancer would be diagnosed.
• A woman has a lifetime risk of developing invasive breast cancer of about one in eight, or 13%.
• Death rates from breast cancer have been gradually declining and continue to decline. These decreases are likely due both to increased awareness and screening and improved treatment methods.
• There are currently about 2.5 million breast cancer survivors in the U.S.

The breasts are made of fat, glands, and connective (fibrous) tissue. The breast has several lobes, which are divided into lobules that end in the milk glands. Tiny ducts run from the many tiny glands, connect together, and end in the nipple.

• These ducts are where 80% of breast cancers occur. Breast cancer that arises in the ducts is called ductal cancer.
• Cancer developing in the lobules is termed lobular cancer. About 10%-15% of breast cancers are of this type.
• Other less common types of breast cancer include inflammatory breast cancer, medullary cancer, phyllodes tumor, angiosarcoma, mucinous (colloid) carcinoma, mixed tumors, and a type of cancer involving the nipple termed Paget's disease.

Precancerous changes, called in situ changes, are common.

• In situ is Latin for "in place" or "in site" and means that the changes haven't spread from where they started.
• When these in situ changes occur in the ducts, they are called ductal carcinoma in situ (DCIS). DCIS may be identified on routine mammography.
• When in-situ changes happen in the lobules, it is called lobular carcinoma in situ (LCIS).

When cancers spread into the surrounding tissues, they are termed infiltrating cancers. Cancers spreading from the ducts into adjacent spaces are termed infiltrating ductal carcinomas. Cancers spreading from the lobules are infiltrating lobular carcinomas.

The most serious cancers are metastatic cancers. Metastasis means that the cancer has spread from the place where it started into other tissues distant from the original tumor site. The most common place for breast cancer to metastasize is into the lymph nodes under the arm or above the collarbone on the same side as the cancer. Other common sites of breast cancer metastasis are the brain, the bones, and the liver.

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