Thigh pain is not necessarily due to cancer, but may also have other causes. There are many common causes of thigh pain, such as prolonged overexertion, sedentary and other reasons leading to slow blood circulation in the thighs, so that metabolic substances in the soft tissues can increase the soreness, usually after rest or activities can be relieved. Herniated lumbar intervertebral disc can also cause soreness if it presses the nerve tissue that innervates the thigh. Although bone cancer or metastatic cancer may also invade or press the nerve tissue innervating the thigh and cause soreness, it usually does not manifest as soreness in the thigh in the first place, and there may be other uncomfortable symptoms. Therefore, thigh pain alone is not necessarily a warning against cancer. If thigh pain does not get better or worsens after rest or activities, you should go to a regular hospital in time and have your doctor determine the cause of the disease based on symptoms, signs and auxiliary examinations.