About Us | Privacy | Site Map
Font Size
A
A
A


Breast Cancer

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 »

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.



Next: Breast Cancer Causes »

Viewer Comments & Reviews

Breast Cancer - How Was It Detected

The eMedicineHealth physician editors ask:

How was your breast cancer detected?

Anonymously share your comment to help others. Viewer Comments FAQs
See 6 Viewer Comments & Reviews

Submit Your Review


Printer-Friendly Format  |  Email to a Friend

Know Your HER2+ Breast Cancer Treatment Options?

Privacy Policy

Breast Cancer

Find support and advances in treatment.

Are You Depressed? Take the Quiz


Breast Cancer

Mammogram »

Mammogram Introduction

A mammogram is a special x-ray examination of the breast made with specific x-ray equipment that can often find tumors too small to be felt. A mammogram is the best radiographic method available today to detect breast cancer early. It is ideal and indispensable for women older than 40 years, for whom the risk of breast cancer is increased.

A woman may experience significant distress, anxiety, and fear associated with the mammogram and with the prospect of discovering a tumor. Be reassured that the procedure itself is relatively simple. Most breast disorders are not cancer, and even in the remaining number of cancer cases, more than 90% are curable, if detected early and promptly treated.

Although mammograms, like many other medical tests, are not 100% accurate, scheduling a regular mammogram represents the best radiological way to find breast changes early before there are any obvious signs or symptoms of cancer. Several studies show that ma...

Read the Mammogram article »



Read What Your Physician is Reading on eMedicine

Breast Cancer »

Breast cancer is the most common cancer and the second most common cause of death from cancer in women.

Read More on eMedicine »

Featured Topics

Topics Related to Breast Cancer

Medical Dictionary


or A-Z List