CancerCare Manitoba
 
 
 
What is Breast Cancer?




Cancer is a disease that is named by where a cancer starts to grow. A breast cancer begins in breast tissue and may start in the duct or lobe of the breast. These tissues are made up of microscopic cells which regularly divide to replace older cells, damaged cells or cells that have died. These cells have built-in controls which tell them when to grow or when to stop growing. When the controls in breast cells are not working properly, they divide continually and a lump or tumor is formed.

Not all tumors or lumps are breast cancer. According to the 3rd edition of Dr. Susan Love's Breast Book, page 118, there are 12 benign (not cancer) lumps in pre-menopausal woman for every malignant (cancer) lump found, while in the post-menopausal woman who is not taking hormone therapy, 50% will be benign and 50% will be breast cancer.

The 2 most common types of breast cancer are: