Cancer Symptoms: Most symptoms and signs of cancer may also be explained by harmless conditions, so it's important to limit one's risk factors and undergo appropriate cancer screening. Common cancer symptoms and signs are a change in bowel habits or urination, persistent cough, blood in the stool, urine, or saliva, lump in the breast or testicle, hoarseness, swollen glands, a change in a wart or mole, unusual vaginal bleeding or discharge, difficulty swallowing, unexplained weight loss, and headaches.