Breast Cancer: Overview and Types

Overview

Cancer is a disease characterized by DNA damage which causes abnormal cell growth and development. Cancer cells no longer divide and differentiate normally. They have the ability to invade surrounding tissues and travel to distant sites. Doctors do not know exactly what causes breast cancer, why it behaves the way it does, or why it spreads in one women and not another.

Breast Anatomy

A woman’s breast is divided into sections called lobes. Each lobe has groups of tiny bulbs called lobules. Lobules produce milk. Thin structures called ducts start from the lobes and carry milk to the nipple, located in the center of the areola. The areola is the dark skin around the nipple. Surrounding the lobules and ducts is fat. Muscles are found over the ribs and under each breast.

The breast contains blood vessels and lymph vessels. Lymph is the clear fluid which contains tissue waste-products and immune system cells. This fluid is carried in lymph vessels that lead to small collections of tissue called lymph nodes. Most of the lymphatic vessels of the breast lead to the lymph nodes under the arm (axillary nodes). Groups of lymph nodes are also located near the breast, above the collarbone, in the chest, and in many other parts of the body.

Source: American Cancer Society (ACS) Web site, www.cancer.org

Types of Breast Cancer

Ductal Carcinoma In Situ (DCIS) – This is non-invasive breast cancer, meaning the cancer is confined to the ducts of the breast. It has not spread through he walls of the ducts into the fatty tissue. It cannot spread to other parts of the body.

Infiltrating (Invasive) Ductal Carcinoma – This is the most common type of breast cancer, accounting for about 80% of invasive types. This cancer starts in a milk passage, or a duct, breaks through the wall of the duct, and invades the fatty tissue of the breast. It does have the ability to spread to other parts of the body.

Lobular Carcinoma In Situ (LCIS) – This is generally considered to be a pre-cancerous condition. It is lobular because the caner is confined to the lobules, which are the glands that actually make milk. In situ or “in its original place” means that the cancer has not spread to any surrounding tissues.

Infiltrating (Invasive) Lobular Carcinoma – This is a cancer which starts in the milk glands or lobules and can spread to other parts of the body.

Inflammatory Breast Cancer – This is a fairly rare type of breast cancer. The breast looks red and swollen and feels warm. The redness and warmth occur because the cancer cells block the lymph vessels in the skin. The skin of the breast may also show a pitted appearance called “peau d’orange” (like the skin of an orange). Sometimes a lump is also found in the breast.

There are several less common types of breast cancer that we can provide information about, if your diagnosis does not include one of the above.

 

Last Updated: May 30, 2008