Cancer is the name for a group of diseases that develop when the body’s cells grow in an uncontrolled way and spread into the body’s tissues. Breast cancer is cancer that starts in the breast tissue

Breasts are made up of lobules and ducts surrounded by fatty and connective tissue:

• lobules produce breast milk
• ducts carry milk to the nipple.

Illustration of a woman's breast including showing ductal carcinoma in situ & invasive breast cancer

Close to the breasts are a number of lymph nodes. These are part of the lymphatic system and help to protect the body from infection. The closest lymph nodes to the breast are in the armpit (axillary nodes). There are also lymph nodes under the breastbone (internal mammary nodes) and in the neck (supraclavicular nodes).

Find out more about:

• The lymphatic system
• Types of breast cancer