Can cancer cause mouth ulcers?
Cancer of the mouth can first appear as a mouth ulcer. The ulcers caused by mouth cancer are usually single and last a long time without any obvious local cause (for example a sharp tooth). Any ulcer that lasts longer than three weeks should be looked at by your dentist. Ulcers caused by cancer usually appear on or under the tongue, but may occasionally appear somewhere else in the mouth. Cancer of the mouth is usually associated with heavy smoking and drinking. Doing both together greatly increases the risk.