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Oral Cancer

Issue Description
Oral cancer is any cancerous tissue growth located in the mouth. It may arise as a primary lesion originating in any of the oral tissues, by metastasis from a distant site of origin, or by extension from a neighboring anatomic structure, such as the nasal cavity or the maxillary sinus. Oral cancers may originate in any of the tissues of the mouth, and may be of varied histologic types: teratoma, adenocarcinoma derived from a major or minor salivary gland, lymphoma from tonsillar or other lymphoid tissue, or melanoma from the pigment producing cells of the oral mucosa.


Types Of Oral Cancer
Melanosarcoma (malignant melanoma) 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 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.

Symptoms
  • Skin lesion, lump, or ulcer on the tongue, lip, or other mouth area. Usually small. Most often pale colored, may be dark or discolored. Early sign may be a white patch (leukoplakia) or a red patch (erythroplakia) on the soft tissues of the mouth. Usually painless initially.
  • May develop a burning sensation or pain when the tumor is advanced.
  • Additional symptoms that may be associated with this disease:
  • Tongue problems.
  • Swallowing difficulty.
  • Mouth sores that do not resolve in 14 days.
  • Pain and paraesthesia are late symptoms.


  • Diagnosis
  • Complete blood cell count, Chemistry profile, Urinalysis are performed to evaluate the overall health of the patient.
  • Chest radiographs (x-rays) are used to help see if the tumor has spread to the lungs.
  • Oral radiographs (x-rays) are taken of the tumor site to see how invasive the tumor is in the bone.
  • Biopsy of the tumor - a small piece of the tumor is sent for analysis by a pathologist to determine the type of tumor that is present as this will give an idea on the prognosis.
  • If any lymph nodes are enlarged, a fine needle biopsy is done to help determine if there is spread to the nodes.
  • After surgery has been completed, the entire tissue specimen is sent to the lab to check the margins to ensure that all of the cancer has been removed.


  • Treatment
    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).

    Complications
  • Postoperative disfigurement of the face, head and neck.
  • Complications of radiation therapy, including dry mouth and difficulty swallowing.
  • Other metastasis (spread) of the cancer.


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