Breast cancer

Breast cancer is a disease in which cells in the breast grow out of control. There are different kinds of breast cancer. The kind of breast cancer depends on which cells in the breast turn into cancer.
Cancer occurs when changes called mutations take place in genes that regulate cell growth. The mutations let the cells divide and multiply in an uncontrolled way.
Breast cancer is cancer that develops in breast cells. Typically, the cancer forms in either the lobules or the ducts of the breast.
The uncontrolled cancer cells often invade other healthy breast tissue and can travel to the lymph nodes under the arms.

Symptoms :

A breast lump or thickening that feels different from the surrounding tissue
Changes to the skin over the breast, such as dimpling
Peeling, scaling, crusting or flaking of the pigmented area of skin surrounding the nipple (areola) or breast skin

Causes :

Breast cancer most often begins with cells in the milk-producing ducts (invasive ductal carcinoma). Breast cancer may also begin in the glandular tissue called lobules (invasive lobular carcinoma) or in other cells or tissue within the breast.