What are the 5 warning signs of breast cancer? The most common symptoms are a change in the look or feel of the breast, a change in the look or feel of the nipple and nipple discharge. The eight warning signs of breast cancer are: Lump, hard knot or thickening. Swelling, warmth, redness or darkening., You can Find A Cancer Hospital Please Join Here, Please join All Cancer Treatment Centers, Be sure to consult your doctor, Health Guide