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Breast Cancer

Breast Cancer Overview
Breast Cancer Causes
Breast Cancer Symptoms
When to Seek Medical Care
Exams and Tests
Breast Cancer Treatment
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Related breast cancer articles:
Breast cancer - on WebMD
Breast cancer - on MedicineNet
Viewer Comments: Breast Cancer - How Was It Detected

BRCA Genes and Your Breast Cancer Risk

Medical Author: Melissa Conrad Stöppler, MD
Medical Editor: Barbara K. Hecht, PhD

BRCA gene mutations increase breast cancer risk. BRCA, known as the "breast cancer gene," is one of several genetic mutations (alterations in the body's genetic material) that have been associated with the development of breast and ovarian cancer. Changes in two genes, known as BRCA1 and BRCA2 (short for breast cancer 1 and breast cancer 2), can be inherited and lead to a markedly increased risk for developing breast cancer and ovarian cancer.

Only about 5% of women with breast cancer are found to carry a mutated BRCA gene. Studies have confirmed that women who carry these BRCA mutations have a high risk for development of breast cancer, up to seven times that of women who do not have BRCA gene alterations. By the age of 80, women with BRCA mutations have about an 80% chance of developing breast cancer. Having a BRCA mutation also predisposes a woman to developing breast cancer at an early age. The incidence of BRCA mutation is higher in some ethnic groups, such as people of Ashkenazi (European) Jewish origin and in some populations in Iceland, the Netherlands, and the Balkans.

Learn more about breast cancer and BRCA testing »

Top Searched Breast Cancer Terms

symptoms, causes, treatments, pain, sentinel node biopsy, prevention, diagnosis, lump, mastectomy, information, mammogram, breast reconstruction, chemotherapy, lumpectomy

Breast Cancer Overview

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, almost 1% of breast cancers occur in men. In 2007, it is estimated that 2,030 men in the U.S. will develop invasive breast cancer.

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 2007, the American Cancer Society estimated that 178,480 new cases of invasive breast cancer would be diagnosed among women in the United States, and that a further 62,030 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.

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. This condition 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.