What is Salivary Gland Cancer?
Salivary gland cancer starts in one of the salivary glands. It's not just one disease. There are actually several different salivary glands found inside and near your mouth. Many types of cancer and benign (non-cancerous) tumors can develop in these glands. Salivary glands make saliva – the lubricating fluid found in the mouth and throat. Saliva contains enzymes that begin the process of digesting food. It also contains antibodies and other substances that help prevent infections of the mouth and throat.
The 2 main types of salivary glands are the major salivary glands and minor salivary glands. There are 3 sets of major salivary glands on each side of the face:
- The parotid glands, the largest salivary glands, are just in front of the ears. About 7 out of 10 salivary gland tumors start here. Most of these tumors are benign (not cancer), but the parotid glands still are where most malignant (cancerous) salivary gland tumors start.
- The submandibular glands are smaller and are below the jaw. They secrete saliva under the tongue. About 1 to 2 out of 10 tumors start in these glands, and about half of these tumors are cancer.
- The sublingual glands, which are the smallest, are under the floor of the mouth and below either side of the tongue. Tumors starting in these glands are rare.
There are also several hundred minor salivary glands that are too small to see without a microscope. These glands are under the lining of the lips and tongue; in the roof of the mouth; and inside the cheeks, nose, sinuses, and larynx (voice box). Tumors in these glands are uncommon, but they are more often cancerous than benign. Cancers of the minor salivary glands most often start in the roof of the mouth.
Benign salivary gland tumors
Most salivary gland tumors are benign – that is, they are not cancer and will not spread to other parts of the body. These tumors are almost never life threatening.
There are many types of benign salivary gland tumors, with names such as adenomas, oncocytomas, Warthin tumors, and benign mixed tumors (also known as pleomorphic adenomas).
Benign tumors are almost always cured by surgery. Very rarely, they may become cancer if left untreated for a long time or if they are not completely removed and grow back. It's not clear exactly how benign tumors become cancers.