Breast cancer may cause abnormal cell growth in one/both breasts. The cells can invade tissue nearby, form a tumor, spread to lymph nodes or other parts of your body. Risk factors you cannot change: your age and genes. Risk factors you can
change: your weight, activity and hormone therapy after menopause.
Breast cancer can cause a painless lump or thickening in the breast/underarm to grow. It may also cause the skin to dimple, like an orange peel. Nipple changes; it may turn inward or look scaley.