Treating Nasal Adenocarcinoma in Dogs
Goals of Treataing Nose Cancer
Nasal adenocarcinoma can be tricky to treat. In many cases, it can be managed, although complete cure is rarely accomplished. Therapeutic goals include alleviating discomfort, preventing further metastasis, removing as much cancerous tissue as possible and prolonging the dog’s good quality of life.
If a dog is having recurrent uncontrollable nose bleeds (epistaxis), immediate medical treatment may include sedation, packing of the nasal passageways with gauze soaked in medication and application of cold compresses to the dog’s nose and muzzle. Antibiotics are available if secondary bacterial infection is confirmed, and either steroidal or non-steroidal anti-inflammatory drugs may be recommended.
Surgery is the treatment of choice for many canine cancers. However, surgery alone is rarely effective to treat nasal adenocarcinoma, because it is virtually impossible to surgically resect all abnormal tissue in the small, confined spaces of the nasal cavities. Certainly, much of the localized affected tissue, including affected turbinate or other facial bones and the tissues that line them, can be surgically removed, either before or after radiation treatment, depending upon the location and severity of cancerous infiltration. The biopsy samples from any surgical excision will be sent to a diagnostic laboratory, where skilled veterinary pathologists will examine the samples grossly and then microscopically to determine the exact type of cancer and whether appropriate surgical margins were obtained. When a focal cancerous mass is removed, the surgeon tries to also remove a small amount of normal tissue around the entire mass of abnormal tissue, in order to achieve what are called “clean surgical margins.” If normal, non-cancerous tissue can be seen microscopically and continuously at and around all edges of the removed cancerous mass, the animal has a greatly reduced risk of metastasis from that tumor site. Unfortunately, this is usually not possible in cases of nasal adenocarcinoma.
Radiation therapy, both internally (called brachytherapy irradiation) and/or externally (teletherapy or external beam radiation), can be used to treat nasal tumors. This type of therapy is designed to kill malignant cancer cells in a defined physical area by exposing them to high levels of deadly radiation. These procedures are usually done daily for several weeks or more and thus are best done on an inpatient basis, with the dog staying in the hospital or with the owner nearby for the duration of treatment, monitoring and supportive care. Radiation treatments are usually well tolerated by most dogs and can prolong survival and improve quality of life. They are available at most veterinary teaching hospitals and at some specialized private veterinary referral centers.
Chemotherapy (treatment with drugs, either intravenously or orally) may be another option for dogs with nasal adenocarcinoma. Chemotherapy is a different way to kill cancer cells. It cannot target a specific physical area of neoplastic cells, but instead travels throughout circulation to target all rapidly-dividing cells in the body. Because of this mode of action, “chemo” is not as effective as radiation treatment for nasal adenocarcinoma. Chemotherapy reportedly may relieve the symptoms of nasal tumors for a number of months, but is not expected to cure the condition or increase survival time overall.
In some cases, veterinarians may recommend a combination of therapies, such as surgery together with radiation and/or chemotherapy. One of the adverse effects of both radiation and chemotherapy is that many normal cells are damaged or destroyed by the treatments. Other existing and emerging treatment options for animals with cancer include targeted molecular therapy, immunotherapy, hyperthermia, cryotherapy, phototherapy, photochemotherapy, thermochemotherapy and other emerging unconventional or alternative therapies. Most of these newer approaches are still not widely available in veterinary medicine. However, they may be worth discussing with a veterinarian as a potential adjunct to more traditional medical therapy.
The goal of treating cancer, of course, is to eliminate only the malignant cells. Unfortunately, it is not presently possible to completely isolate healthy tissue from cancerous tissue during these surgical, radiation or chemotherapeutic treatments. Owners can expect to see some side effects in their dogs, such as nausea, vomiting, diarrhea, weakness, lethargy, lack of appetite and weight loss.
The prognosis for dogs with any form of cancer is highly variable, depending upon the type of cancer involved, the location of the tumor(s), whether the cancer is malignant and has metastasized, whether the disease was caught early or late in its progress, the commitment and financial status of the owner and the body condition, appetite, activity level and overall health of the affected animal. Despite the severity and scariness of any cancer diagnosis, some dogs with nasal adenocarcinoma can be well-managed with timely detection and aggressive therapy and may live happily for months or even years.