Salivary Gland Tumors

views updated May 18 2018

Salivary Gland Tumors

Definition

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, cancers that by definition begin in epithelial cells.

Demographics

Cancers in the mouth account for fewer than 2% of all cases of cancer and about 1.5% of cancer deaths. 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.

Mortality from salivary gland tumors in the United States is higher among male African Americans below the age of 50 than among older workers of any race or either sex. The reasons for these findings are not clear as of early 2004.

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, particularly gamma 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 herpes viruses 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.

Although there has been speculation that the electromagnetic fields generated by cell phones increase the risk of salivary gland tumors, a recent study done in Denmark has concluded that the use of cell phones, pagers, and similar devices is not a risk factor.

There seems to be some link between breast cancer and salivary gland tumors. Women with breast cancer are more likely to be diagnosed with salivary gland tumors. Also linked to salivary gland tumors is alcohol use, exposure to sunlight (ultraviolet radiation) and hair dye use. There is evidence that people infected with herpes viruses may be at greater risk for salivary gland tumors. 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). In many cases, the tumor is first discovered by the patient's dentist. During regular dental examinations, the dentist looks for masses on the palate or under the tongue or in the cheeks, and such checkups are a good way to detect tumors early. Some symptoms are:

a lump or mass in the mouth
swelling in the face
pain in the jaw or the side of the face
difficulty swallowing
difficulty breathing
difficulty speaking

Diagnosis

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 tapped as a way of studying the jaw, which is bone.

Treatment

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; chemotherapy of salivary gland cancers, however, does not appear to extend survival or improve the patient's quality of life. 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.

A promising form of treatment for patients at high risk of tumor recurrence in the salivary glands near the base of the skull is gamma knife surgery. Used as a booster treatment following standard neutron radiotherapy, gamma knife surgery appears to be well tolerated by the patients and to have minimal side effects.

Alternative treatment

Any technique, such as yoga, meditation or biofeedback, that helps a patient cope with anxiety over the condition and discomfort from treatment is useful and should be explored as an option.

Prognosis

Tumors in small salivary glands that are localized 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.

Prevention

Minimizing intake of beverages containing alcohol may be important. Avoiding unnecessary exposure of the head to radiation and to sunlight 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.

A salivary gland with a tumor.

KEY TERMS

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.

Resources

BOOKS

Beers, Mark H., MD, and Robert Berkow, MD., editors. "Disorders of the Oral Region: Neoplasms." Section 9, Chapter 105 In The Merck Manual of Diagnosis and Therapy. Whitehouse Station, NJ: Merck Research Laboratories, 2004.

PERIODICALS

Day, T. A., J. Deveikis, M. B. Gillespie, et al. "Salivary Gland Neoplasms." Current Treatment Options in Oncology 5 (February 2004): 11-26.

Douglas, J. G., D. L. Silbergeld, and G. E. Laramore. "Gamma Knife Stereotactic Radiosurgical Boost for Patients Treated Primarily with Neutron Radiotherapy for Salivary Gland Neoplasms." Stereotactic and Functional Neurosurgery 82 (March 2004): 84-89.

Johansen, C. "Electromagnetic Fields and Health Effects—Epidemiologic Studies of Cancer, Diseases of the Central Nervous System and Arrhythmia-Related Heart Disease." Scandinavian Journal of Work and Environmental Health 30, Supplement 1 (2004): 1-30.

Lawler, B., A. Pierce, P. J. Sambrook, et al. "The Diagnosis and Surgical Management of Major Salivary Gland Pathology." Australian Dental Journal 49 (March 2004): 9-15.

Wilson, R. T., L. E. Moore, and M. Dosemeci. "Occupational Exposures and Salivary Gland Cancer Mortality among African American and White Workers in the United States." Journal of Occupational and Environmental Medicine 46 (March 2004): 287-297.

Zheng, R., L. E. Wang, M. L. Bondy, et al. "Gamma Radiation Sensitivity and Risk of Malignant and Benign Salivary Gland Tumors: A Pilot Case-Control Analysis." Cancer 100 (February 1, 2004): 561-567.

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." American Cancer Society. Revised May 22, 2000. 〈http://www3.cancer.org/cancerinfo〉.

Gale Encyclopedia of Medicine, 3rd ed. Calabrese, Diane; Frey, Rebecca

Salivary Gland Tumors

views updated May 14 2018

Salivary gland tumors

Definition

A salivary gland tumor is an uncontrolled growth of cells that originates in one of the many saliva-producing glands in the mouth.

Description

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 herpes viruses 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:

lump or mass in the mouth
swelling in the face
pain in the jaw or the side of the face
difficulty swallowing
difficulty breathing
difficulty speaking

Diagnosis

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

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.

See Also Oral cancer; Oropharyngeal cancer

Resources

BOOKS

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

KEY TERMS

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.