What are oral tumors?
Oral tumors, the fourth most common type of tumor in dogs, arise from both soft tissue and bony structures within the mouth and can include less common locations such as the tongue and tonsils. They can be either benign and cured with surgical removal, or malignant and require more aggressive therapy including surgery, chemotherapy and/or radiation. General categories of tumors include the epulides (fibromatous, ossifying, and acanthomatous), locally invasive malignant tumors (fibrosarcoma, soft tissue sarcoma, and squamous cell carcinoma), and malignant tumors that have a higher rate of spreading (metastasis) to other parts of the body (melanoma, osteosarcoma).
Depending on the size of the mass and its location, a fine needle aspirate or incisional (wedge) biopsy may be performed under general anesthesia. Sometimes these biopsy tests do not give an accurate diagnosis; therefore, only after the entire tumor is removed and studied by a pathologist can a final diagnosis be made. Chest X-rays are used to identify visible spread of the cancer; however, microscopic spread of the tumor to other organs cannot be detected with this test. X-rays of the tumor site may help determine if the tumor has invaded into the bone. A CT scan of the jaw may also be recommended to further evaluate the extent of the tumor. Enlarged lymph nodes will be checked for spread of cancer via biopsy. A complete blood count, biochemical profile and urinalysis are performed before surgery to check internal organ health.
The goal of surgery is to remove the entire tumor with curative intent. Removal of any part of the upper jawbone is termed a maxillectomy. Removal of any part of the lower jawbone is termed a mandibulectomy. The amount of the jaw that is removed is dependent on the size and location of the tumor. There can be instances where massive amounts of the upper jawbone need to be removed or when one side of the lower jaw is completely removed. Despite removing such a large portion of the jaw, the cosmetic outcome is very good in most cases
If your companion has a tumor that tends to spread (metastasizes), chemotherapy will be recommended and is administered every third week for a total of five treatments. Unlike humans, most dogs do not lose their hair and usually have only mild side effects, which may include transient loss of appetite and vomiting. Certain types of tumors cannot be cured with surgery alone, therefore radiation therapy is needed to help delay the regrowth of residual cancer cells in the mouth. Radiation is administered daily (Monday through Friday) until 18 to 21 treatments have been completed.
The prognosis for your companion is dependent on biopsy results, location, and size of the tumor. In general, tumors located on the front part of the jaw have a better prognosis. The oncologist will discuss the prognosis for your pet and need for additional treatments after the final biopsy results are available.
For more information on this subject, speak to the veterinarian who is treating your pet.