My dog, a 15-year old golden retriever, has been diagnosed with cancer. He has a tumor on both the inside and outside of his right jaw. What kind of cancer is this? What treatment is available?
The traditional treatment options for jaw cancer will be dictated by the location and extent of the primary cancer, the presence and location of metastasis (spread), and the specific cellular diagnosis of the cancer. In most cases surgical removal is indicated. Some tumors may be treated with radiation; others may be amenable to chemotherapy or immunotherapy. However, these non-surgical treatments are typically more effective when only a small number of tumor cells are present or when the tumor burden is low (especially if only microscopic amounts of disease are present).
I will offer you some general information about the most common oral tumors, which tend to affect the jaw. Other tumor types are possible, but occur less commonly. Melanosarcoma (malignant melanoma) occurs most commonly. This tumor usually arises on the mucous membranes of the gums and commonly spreads to regional lymph nodes and other parts of the body, especially the lungs and the kidneys. Melanosarcoma may also develop, although less commonly, on the lips, tongue and hard palate. This cancer mostly develops in older dogs; males are affected more often than females. The prognosis is improved by definitive and early surgical removal. Radiation and chemotherapy are used sometimes after surgery, especially if complete surgical excision is not possible. In general, however, the prognosis is considered to be poor to fair.
Squamous cell carcinoma is a bit less common than melanosarcoma. It also tends to occur on the front aspect of the lower jaw, but does not tend to spread to distant areas unless it arises on the tonsils or tongue. Involvement of the tongue and tonsil is rather common. Males and females are equally affected except in tonsillar tumor cases, where male dogs are more likely to develop this lesion. Squamous cell cancer occurs mostly in older dogs. It is often responsive to radiation, and in some cases, hyperthermia (high temperatures). However, treatment of squamous cell carcinoma of the tonsils and tongue requires surgery as well. The prognosis is better for tumors located on the front of the jaw than on the back of it; tumors of the tonsils and tongue have a poorer prognosis than squamous cell cancer of the gums and buccal mucosa. Tumors arising on the top jaw carry a better prognosis.
Fibrosarcoma is the next most common type of canine oral cancer, occurring usually on the gums (gingivae)
and occasionally on the palate. It tends to occur in middle-aged dogs; males are more commonly affected than females. These tumors rarely spread to other areas, so the prognosis is better if they can be controlled locally with surgery. However, the rate of tumor recurrence may exceed 20 percent. Radiation and hyperthermia treatments are sometimes employed in addition to surgery. In general the prognosis is poor to fair.
Dental tumors, a fourth category of oral cancer, are strictly local and never spread. They tend to occur more frequently in females and in middle-aged to older dogs. Dental tumors carry an excellent prognosis if removed surgically and treated with radiation. These tumors can involve a large amount of bone tissue and may be disfiguring, but since they are often on the front of the jaw, surgery is often very successful. Dogs rarely die from dental tumors.
I urge you to seek the opinion of a veterinary oncologist who can discuss the most appropriate conventional or alternative treatments for your pet's condition. Your veterinarian can arrange a referral to a specialist in your area.
01/12/01
