The cancer starts from a cell within the breast and then start multiplying at uncontrollable pace.Chances of breast cancer increases with age.First symptom of breast cancer is lump in breast or around breast like armpit.Other signs to be noticed are any sudden change in size and shape of breast,discharge from nipples, swelling in the breast or armpit,shape of nipple getting inverted or deformed.The skin can also look red,inflamed and sore if the cancer is of inflammatory type.