A salivary gland tumor is an uncontrolled growth of cells that originates in one of the many saliva-producing glands in the mouth.
Description
The tongue, cheeks, and palate (the hard and soft areas at the roof of the mouth) contain many glands that produce saliva. In saliva there are enzymes, or catalysts, that begin the breakdown (digestion) of food while it is still in the mouth. The glands are called salivary glands because of their function.
There are three big pairs of salivary glands in addition to many smaller ones. The parotid glands, submandibular glands and sublingual glands are the large, paired salivary glands. The parotids are located inside the cheeks, one below each ear. The submandibular glands are located on the floor of the mouth, with one on the inner side of each part of the lower jaw, or mandible. The sublingual glands are also in the floor of the mouth, but they are under the tongue.
The parotids are the salivary glands most often affected by tumors. Yet most of the tumors that grow in the parotid glands are benign, or not cancerous. Approximately 8 out of 10 salivary tumors diagnosed are in a parotid gland. One in 10 diagnosed is in a submandibular gland. The remaining 10% are diagnosed in other salivary glands.
In general, glands more likely to show tumor growth are also glands least likely to show malignant tumor growth. Thus, although tumors of the sublingual glands are rare, almost all of them are malignant. In contrast, about one in four tumors of the parotid glands is malignant.
Cancers of the salivary glands begin to grow in epithelial cells, or the flat cells that cover body surfaces. Thus, they are called carcinomas.
Demographics
About 7% of all cancers diagnosed in the head and neck region are diagnosed in a salivary gland. Men and women are at equal risk.
Causes and symptoms
When survivors of the 1945 atomic bombings of Nagasaki and Hiroshima began to develop salivary gland tumors at a high rate, radiation was suspected as a cause. Ionizing radiation is a factor that contributes to tumor development. So is radiation therapy. Adults who received radiation therapy for enlarged adenoids or tonsils
when they were children are at greater risk for salivary gland tumors.
Another reported risk factor is an association between wood dust inhalation and adenocarcinoma of the minor salivary glands of the nose and paranasal sinuses. There is also evidence that people infected with herpesviruses may be at greater risk for salivary gland tumors. And individuals infected with human immunodeficiency virus (HIV) have more salivary gland disease in general, and may be at greater risk for salivary gland tumors.
Symptoms are often absent until the tumor is large or has metastasized (spread to other sites). During regular dental exams, however, the dentist looks for masses on the palate or under the tongue or in the cheeks, and such check-ups are a good way to detect tumors early. Some symptoms are:
A tissue sample will be taken for study via a biopsy. Usually an incision is necessary to take the tissue sample. Sometimes it is possible to take a tissue sample with a needle.
Magnetic resonance imaging (MRI) and computed tomography (CT) scans are also used to evaluate the tumor. They help determine whether the cancer has spread to sites adjacent to the salivary gland where it is found. MRI offers a good way to examine the tonsils and the back of the tongue, which are soft tissues. CT is used as a way of studying the jaw, which is bone.
Treatment team
Generally, physicians with special training in the organs of the nose and throat take responsibility for the care of a patient with a salivary gland cancer. They are called otolaryngologists or occasionally by a longer name, otorhinolaryngologists.
For short, otolaryngologists are usually labeled ENT (for Ear, Nose and Throat) specialists. An ENT specializing in cancer will probably lead the team. An oncologist or radiation therapist may be involved, and nurses, as well as a nutritionist, speech therapist and social worker, will also be part of the team. Depending on the extent of the cancer when diagnosed, some surgery and treatments
result in extensive changes in the throat, neck and jaw. The social worker, speech therapist and nutritionist are important in helping the patient cope with the changes caused by surgery and radiation treatment. If there is great alteration to the neck because of surgery, rehabilitation will also be part of the recovery process and a rehabilitation therapist will become a member of the team.
Clinical staging, treatments, and prognosis
To assess the stage of growth of a salivary gland tumor, many features are examined, including how big it is and the type of abnormal cell growth. Analysis of the types of abnormal cell growth in tissue is so specific that many salivary gland tumors are given unique names.
In stage I cancer the tumor is less than one inch in size and it has not spread. Stage II salivary gland cancers are larger than one inch and smaller than two and one-half inches, but they have not spread. Stage III cancers are smaller than one inch, but they have spread to a lymph node. Stage IV cancers have spread to adjacent sites in the head, which may include the base of the skull and nearby nerves, or they are larger than two and one-half inches and have invaded a lymph node.
Surgical removal (excision) of the tumor is the most common treatment. Chemotherapy and radiation therapy
may be part of the treatment, particularly if the cancer has metastasized, or spread to other sites. Because there are many nerves and blood vessels near the three major pairs of salivary glands, particularly the parotids, the surgery can be quite complicated. A complex surgery is especially true if the tumor has spread.
Tumors in small salivary glands that are localized and can usually be removed without much difficulty. The outlook for survival once the tumor is removed is very good if it has not metastasized.
For parotid cancers, the five-year survival rate is more than 85% whether or not a lymph node is involved at diagnosis. Ten-year survival rate is just under 50%.
Most early stage salivary gland tumors are removed, and they do not return. Those that do return, or recur, are the most troublesome and reduce the chance an individual will remain cancer-free.
Alternative and complementary therapies
Techniques such as yoga, meditation, or biofeedback can help a patient cope with anxiety over the condition and discomfort from treatment and should be explored as an option.
Coping with cancer treatment
A support group helps during the course of treatment and follow-up. Patients are encouraged to join one. They should also be encouraged to take an active role in following the recommendations and decisions made by the treatment team.
Clinical trials
There are a number of clinical trials in progress. For example, the more researchers understand the nature of cancer cells, the better they are able to design drugs that attack only cancer cells. Or, in some cases, drugs that make it easier to kill cancer cells have also been designed.
The Cancer Information Service at the National Institutes of Health offers information about clinical trials that are looking for participants. The service can be contacted at (800) 422-6237.
Prevention
Minimizing intake of alcoholic beverages may be important. Avoiding unnecessary exposure of the head to radiation may also be considered preventative. Anything that reduces the risk of contracting a sexually transmitted disease, such as the use of condoms, also may lower the risk of salivary gland cancer.
Special concerns
Salivary gland tumors are considered rare. Because there are so many salivary glands, and so many types of salivary tumors, most physicians (even those who specialize in diseases of the ears, nose and throat) are challenged when they must interpret results of study of tumor tissue. For treatment of a salivary gland tumor, it is best to find a medical facility that specializes in diseases of the head and neck. Such a facility will be better able to match treatment to the specific characteristics of the tumor.
Atkinson, Lucy Jo, and Nancymarie Fortunato. "Head and Neck Surgery." In Berry & Kohn's Operating Room Tech nique. St. Louis: Mosby, 1996.
ORGANIZATIONS
SPOHNC, Support for People with Oral and Head and Neck Cancer. P.O. Box 53, Locust Valley, NY 11560-0053. (800) 377-0928. <http://www.spohnc.org>.
OTHER
Oral Cavity and Pharyngeal Cancer Online text. American Cancer Society. Revised 05/22/2000. 18 July 2001 <http://www3.cancer.org/cancerinfo>.
Diane M. Calabrese
Adenoids
—Common name for the pharyngeal tonsils, which are lymph masses in the wall of the air passageway (pharynx) just behind the nose.
Biopsy
—Tissue sample is taken from the body for examination.
Computed tomography (CT)
—X rays are aimed at slices of the body (by rotating equipment) and results are assembled with a computer to give a three-dimensional picture of a structure.
Lymph
—Tissue that is part of the lymphatic system, the system that collects and returns fluid to the blood vessels and produces substances that fight infection.
Magnetic resonance imaging (MRI)
—Magnetic fields and radio frequency waves are used to take pictures of the inside of the body.
Tonsils
—Common name for the palatine tonsils, which are lymph masses in the back of the mouth, on either side of the tongue.
