A cancer that involves the throat just behind the mouth. This area is called the oropharynx. The oropharynx begins where the oral cavity stops. It includes the base of the tongue, the soft palate, the tonsils, and the side and back wall of the throat. There are many different cell types in these areas and different cancers can develop from each type of cell. Some of these cancers are benign and others are malignant.