Breast Cancer
Cancer develops when changes in genes that control cell development, known as mutations, occur. Mutations allow cells to divide and replicate in an uncontrollable manner. Breast cancer is thus a type of cancer that occurs in the cells of the breast. This cancer usually develops in the lobules or ducts within the breast. The glands that create milk are lobules, while the ducts are responsible for transporting the milk from the glands to the nipple.
Also, breast cancer can develop within the fatty tissue or fibrous connective tissue. Uncontrolled cancerous cells usually penetrate the healthy breast tissue and might spread to lymph nodes beneath the arms. These lymph nodes are a major passage that allows the malignant cells to travel to various body parts.