Pancreatic Adenocarcinomas In Dogs

The second most common gastrointestinal malignancy is ‘Pancreatic cancer’. In general, the term “pancreatic cancer” is used to refer to pancreatic adenocarcinoma.

In spite of its low occurrence when compared to other more common malignancies (lung, colorectal, esophagus, prostate, etc), pancreatic cancer is one of the leading causes of death in dogs.

The most common type of pancreatic cancer is Adenocarcinoma and it accounts for almost 90 percent of pancreatic cancer diagnoses. The exocrine portions of the pancreas are where 95% of malignant neoplasms arise (acinar and ductal cells) and this exhibit features comparable with adenocarcinoma.

Simply, Adenocarcinomas are the cancerous counterparts to adenoma. They are described as malignant neoplasms originating in the glandular tissue that lines the inside of one of the organs. Although rare in dogs, this carcinoma grows rapidly and metastasizes to distant parts and organs of the body.

Similar to other types of cancer, pancreatic cancer usually affects older dogs (> 8 years). There is no gender or breed disposition, but female dogs are found to be at higher risk than others.

• Loss of consciousness (syncope).
• Lack of coordination.
• Yellowing of the skin and the whites of the eyes (jaundice).
• Reduced ability or enthusiasm to exercise.
• Disturbance of vision.
• Fatigue / Seizures
• Diabetes
• Decrease in the reflex of appendages.
• Muscle Twitching.

Discuss the best treatment option with your veterinarian or canine oncologist.

Steroid Treatment:

(Prednisolone): 2 mg/kg (or 40 mg/m²) PO daily.

By itself, the antitumor dosage of prednisone increases average survival times to 1 to 3 months, but it is not beneficial in all cases. Sometimes, it makes subsequent chemotherapy treatment less successful.

Chemotherapy:

• Chemotherapeutic agents, such as streptozocin - nitrosourea alkylating agent.
• Every 2 to 3 weeks -500 mg/m².

Surgical Removal Of Tumor: The best chance for relief of clinical signs and the best survival times.

Partial Pancreatectomy - Removal of part of the pancreas.

Exploratory Abdominal Surgery - dogs with hypoglycemia and inappropriate insulin production.

Check with your veterinarian or Veterinary oncologist for the post-surgical checks, usually once a month to ensure the health of the dog and to check for any infection.

Until the post-operative recovery period is over, do not allow your dogs to play outdoors. This will reduce the risk of infection and injuring the surgical site.

Prevention is not possible for pancreatic cancer as the causes in dogs is varied. Treatment and survival rates vary depending on the grade and stage of cancer.

Good overall health and early detection are the only ways to prevent adenocarcinoma.

Check your dog on a regular basis and consult your veterinarian immediately if you find any odd lumps or lesions.

Medium to large breeds are overrepresented. Female dogs are more reported.

Golden Retriever, Airedale Terrier, Irish Setter, German Shepherd, Spaniel Dog Breeds, Boxer, Senior Dogs, Terrier Dog Breeds

Causes:

As with other forms of cancer, any definitive causation of pancreatic cancers, (including pancreatic adenocarcinoma) is not yet identified.

It is alleged that there is a genetic component linked to the odds of this cancer occurring, supported by higher incidence in certain breeds.

Types:

The pancreas has both functions - exocrine (enzymes of digestion) and endocrine (hormones that affect other parts of the body).

Pancreatic adenocarcinomas are either exocrine or neuroendocrine (endocrine) tumors.

Exocrine Tumors: More than 90% of pancreatic cancers are exocrine. They are usually aggressive and spread to nearby tissues as well as to the other organs throughout the dog’s body. The most common type of pancreatic cancer is adenocarcinoma.

Neuroendocrine Tumors: Their incidence is Less than 10% and they often grow slower than exocrine tumors (Islet Cell Carcinomas).

Morbidity:

Staging:

• Stage I: Limited to the pancreas.
• Stage II: Metastasis to the regional lymph node.
• Stage III: Metastasis to distant organs.

Mortality:

For dogs undergoing surgery:

• In stage 1: 785 days (MST –median survival time).
• In stage 2: 380 MST
• In Stage 3: 217 MST

For medical management:

• 2½ months (Tobin et al 1999)
• 196 days (Polton et al)

Diagnosis:

• Routine Hematology, Urinalysis
• Glucose Level Exams
• Test for Hypoglycemia
• Abdominal Ultrasound / CT Scan

Prognosis:

Following a diagnosis of pancreatic cancer in dogs, life expectancy is related to the development of postoperative complications.

Life expectancy is greatly reduced for dogs that are not good surgical candidates or for owners who are not interested in surgery and opt for medical management.

Time to visit the vet clinic for an examination, if you notice any of the following:

• When you see your dog has extreme fatigue after exercise and higher collapsing episodes.
• When your dog has prolonged seizure activities.
• Muscle Degeneration

The ratio would be:

35 to 50 percent protein + less than 25 percent carbs + 25 to 35 percent fat (including omega-3 fatty acids).

• Low fat, high protein foods - White-Fleshed Fish, Skinless, White-Meat Poultry, Beans, Peas, and Lentils.
• Protein: High protein diet comprises 35 - 50% of the dog's calories.
• Protein - Chicken Breasts, turkey breasts, liver, ½ Cup Raw Salmon (or cooked).
• Lean meats, such as chicken breast, sirloin, or pork.
• Fats - Chicken / Turkey fat or beef tallow.
• DHA-mackerel, salmon, herring, sardines, and caviar.
• Complex Carbohydrates: Fibers and starches (Whole Grains, Oatmeal, Brown Rice, Potatoes & Sweet Potatoes).

The prognosis is guarded at best due to this malignant neoplasia’s high frequency of metastasis. Metastatic pets survive up to 10 months with a combination of surgery and medical therapy.

However, for dogs in the initial stages, Surgery is recommended as it provides the best-reported survival times (up to 2 years and more).

Medical management of dogs does not make them survive longer than 6 months from the onset of clinical signs.