The parotid gland is the largest of the major salivary glands and the most likely to develop cancer. It is located in the cheek in front of the ear. The smaller major salivary glands are the sublingual salivary glands, which are under each side of the tongue, and the submandibular glands, which are under and inside the lower jaw bone (the mandible), toward the back. There are also a number of small minor salivary glands in the mouth. The salivary glands produce saliva, which helps keep the mouth moist and aids in digestion. Several different types of cells can be found in salivary glands; as a result, several different types of cancers can develop. Some are slow growing; others are more aggressive. The risk of parotid and other salivary gland cancers seems to increase following radiation exposure. The risk also tends to go up with age; salivary gland cancers are most common in people age 55 or older. Overall, salivary gland cancers are quite rare, occurring in approximately two in every 100,000 people each yar in the United States.''
