SmallAnimalOncology

Small Animal Oncology: 

Small Animal Oncology Vance Kawakami Kristin Kender

Cancer Statistics: 

Cancer Statistics Cancer is the major cause of death in pets greater than 10 years old 45% of all dogs older than 10 years of age die of cancer 23% of all dogs die of cancer

Feline Cancer Facts: 

Feline Cancer Facts Lymphoma is the most frequently diagnosed tumor in cats Spaying female cats decreases the incidence of lymphoma by 40-50%

Canine Cancer Facts: 

Canine Cancer Facts Skin cancers are the most frequently diagnosed tumors of dogs. Mastocytomas account for 23% Mammary tumors are the most common tumors in female dogs. Spaying a dog prior to her first heat cycle will decrease the risk of developing mammary cancer by 7-fold.

Contributors to an IncreasingIncidence of Cancer: 

Contributors to an Increasing Incidence of Cancer Larger population of geriatric pets Advances in health care An improved recognition and diagnosis of cancer Increased willingness of both veterinarian and owner to treat cancer Environmental changes

What is cancer?: 

What is cancer? Cancer is a group of neoplastic diseases in which there is a transformation of normal body cells into malignant ones.

PTH 551: 

PTH 551 Thank you Dr. Patterson!

AVMA’s Signs of Cancer: 

AVMA’s Signs of Cancer Abnormal swelling that persists or cont. to grow Sores that do not heal Unexplained weight loss Loss of appetite Bleeding or discharge from any body opening Bad odor, especially from the mouth Difficulty eating or swallowing Reluctance to exercise or loss of stamina Difficulty breathing, urinating, defecating Change in behavior

Diagnostic Tests and Procedures: 

Diagnostic Tests and Procedures CBC Serum chemistry profile Urinalysis Radiographs CAT scan MRI Ultrasonography Biopsy Tumor staging

Biopsy: 

Biopsy Excisional Complete removal of the tumor Feasible if mass is < 3 cm in diameter and freely moveable Lymph nodes, small cutaneous nodules, mammary gland and CNS tumors, and tumors found during exploratory surgeries Nonexcisional Removal of only a portion of the tumor Cytology from a fine-needle aspirate, brush samples, or impression smears or effusions Histopathology of cutting forcep biopsies, cutting needle biopsies, punch biopsies, and incisional biopsies

Tumor-Node-Metastasis System: 

Tumor-Node-Metastasis System T = primary tumor size or extent Tis: preinvasive tumor (in situ) T0: no evidence of tumor T1: tumor <5 cm in diameter but confined to primary site T2: tumor >5 cm in diameter or ruptured tumor T3: infiltrative tumor a: no bone invasion b: bone invasion N = nodes N0: no evidence of lymph node enlargement N1: moveable ipsilateral nodes enlarged N2: moveable contralateral/bilateral nodes enlarged N3: fixed nodes M = metastasis M0: no metastasis M1: metastasis detected

Curative vs. Palliative Treatment: 

Curative vs. Palliative Treatment Curative The likelihood that a given tumor type will be controlled for at least one year following treatment. Palliative Designed to reduce pain or functional difficulties such as swallowing, urinating, etc. without attempting to cure the tumor

Methods of Treatment: 

Methods of Treatment Surgery Radiation therapy Chemotherapy Hyperthermia Photodynamic therapy Others Gene therapy Anti-angiogenic drugs Immunotherapy Alternative therapies

Surgery: 

Surgery

Surgery-Indications: 

Surgery-Indications Mammary tumors (except inflammatory mammary cancer) Prostate tumors Oropharyngeal tumors Skin cancers GI tumors Lung tumors Bone tumors

Surgery-Limitations and Complications: 

Surgery- Limitations and Complications Risks increase with age of patient Most mortalities resulting from surgery are associated with: pulmonary emboli Pneumonia cardiovascular collapse primary disease Other complications include: Abscesses wound infections blood loss incomplete wound healing

Radiation: 

Radiation

Radiation-Indications: 

Radiation-Indications Brain tumors Curative: small pituitary tumors Longer survival time: intracranial tumors and spinal lymphomas Tumors of the nasal cavity Thyroid tumors Soft tissue sarcomas Mast cell tumors

Radiation-Limitations and Complications: 

Radiation- Limitations and Complications Survival of cancer cells at the center of larger tumors Local effects to skin, lining of GI tract, and hair Long term effects: Necrosis Non-healing ulcerations Organ dysfunction blindness

Radiation + Surgery: 

Radiation + Surgery Used prior to surgery to shrink tumor size Used following surgery to destroy remaining cancer cells that were left behind Limitations: Radiation must be postponed until surgical incision has completely healed Cancer cells in the area of scar tissue are often more resistant to radiation

Chemotherapy: 

Chemotherapy

Chemotherapy-Indications: 

Chemotherapy-Indications As sole agent Systemic cancers hematologic malignancies metastatic carcinomas Metastatic sarcomas As adjunct therapy Given to patients with no overt evidence of residual cancer following surgery or radiation

Chemotherapy-Limitations and Complications: 

Chemotherapy- Limitations and Complications Toxicities are particularly against cells of the bone marrow, GI lining, and hair follicles and can result in: Immunosuppression Anemia Nausea and vomitting Delayed wound healing Hair loss

Chemotherapy as anAdjunctive Therapy: 

Chemotherapy as an Adjunctive Therapy Chemotherapy + Radiation Certain drugs are radiosensitizers This increases the efficacy of the radiation Help slow down metastatic growth Chemotherapy + Surgery Shrink large tumors prior to surgery Help eradicate microscopic cancer cells which remain after surgery Help slow down metastatic growth

Hyperthermia: 

Hyperthermia

Hyperthermia-Indications: 

Hyperthermia-Indications Most effective in the treatment of localized tumors in combination with radiation or chemotherapy Used to treat small (<1.0 cm in diameter) benign and malignant superficial tumors

Hyperthermia-Limitations and Complications: 

Hyperthermia- Limitations and Complications Equally damaging to both cancer and normal cells Frequency of skin burns and infarcts can be as high as 45%

Hyperthermia as anAdjunctive Therapy: 

Hyperthermia as an Adjunctive Therapy Hyperthermia + Radiation In humans, combining these two therapies to treat cancer was found to double the number of complete responses In dogs, this combination improved the rate of complete response in primary tumors resulting in prolonged survival time However, many dogs later succumb to metastatic disease Hyperthermia + Chemo. Some drugs work more efficiently above normal body temperatures Hyperthermia may offer a protective effect for normal tissues against drug toxicities Some studies have shown that combining these therapies actually increases toxicity

Photodynamic Therapy (PDT): 

Photodynamic Therapy (PDT)

PDT-Indications: 

PDT-Indications Has been used limitedly in veterinary medicine Used in dogs with localized, superficial, and minimally invasive tumors such as those affecting skin and linings of urinary bladder and oral cavity

Photodynamic Therapy-Limitations and Complications: 

Photodynamic Therapy- Limitations and Complications Inability of light to penetrate deeply into tumor tissue Tissue retention time of photosensitizers Patient must remain in subdued light for 4-6 weeks Not all tumors absorb photosensitizers at same rate and at same concentration

Other Treatment Options: 

Other Treatment Options Gene therapy Anti-angiogenic drugs Immunotherapy Alternative therapies Acupuncture Massage Herbal and botanical medicine

Gene Therapy: 

Gene Therapy Suicide gene therapy Genetic immunotherapy Tumor suppressor gene therapy Drug resistance gene therapy

Anti-Angiogenic Drugs: 

Anti-Angiogenic Drugs Inhibit tumor growth by cutting off tumor’s blood supply Many of these drugs are in the early stages of clinical development in the treatment of both human and canine cancer

Immunotherapy: 

Immunotherapy Biologic Reponse Modifiers: Nonspecific immunomodulators Lymphokines/monokines Adoptive cellular therapy Antibody therapy Growth factors Indications: Lymphoma Melanoma Mastocytoma Oteosarcoma Soft tissue sarcomas, including fibrosarcoma and hemangiosarcoma

Alternative Therapies: 

Alternative Therapies Acupuncture Palliative treatment Pain Post-op & chemo-induced nausea and vomiting Massage May be contraindicated Herbal and Botanical Medicine Herbs are used in conjunction with chemotherapy or radiation to help strengthen the individual and mitigate side effects

Nutritional Management: 

Nutritional Management Often ignored aspect of cancer treatment Important in treating cancer cachexia May control growth of certain tumors Decrease side effects of cancer treatments

Assessment of Nutrition status: 

Assessment of Nutrition status Animals with cancer have alterations in metabolism which results in clinical alterations This occurs early in all cancers and decreases quality and quantity of life Broken in four phases

Phase 1: 

Phase 1 Clinical changes Preclinical, silent phase, no obvious signs. Metabolic changes Hyperlactermia Hyperinsulinemia Altered blood amino profiles

Phase 2: 

Phase 2 Clinical changes Early clinical signs: Anorexia, Lethargy Mild weight loss More susceptible to side effects from chemotherapy, sx, etc.. Metabolic changes Similar metabolic changes

Phase 3 (cancer cachexia): 

Phase 3 (cancer cachexia) Clinical changes Cachexia Anorexia Lethargy More susceptible to side effects from chemotherapy, sx, etc.. Metabolic changes Similar changes but more profound

Phase 4 (recovery or remission): 

Phase 4 (recovery or remission) Clinical changes Recovery, Remission Metabolic changes Metabolic changes may persist Changes secondary to surgery, chemotherapy, or radiation therapy

Nutritional management: 

Nutritional management Specific nutritional requirements of animals with cancer is unknown Nutrients in order of importance water calories and protein minerals and vitamins

Cancer’s effect on metabolism: 

Cancer’s effect on metabolism Carbohydrate metabolism Tumors preferentially metabolize glucose for energy by anaerobic glycolysis forming lactate buildup of lactate results in net energy loss by the body and net gain by the tumor (uses ATP to convert lactate to glucose)

Cancer’s effect on metabolism: 

Cancer’s effect on metabolism Protein metabolism Good source of energy for tumor Can result in clinically significant deficiency in AA decreased immune function surgery healing decreased GI function

Cancer’s effect on metabolism: 

Cancer’s effect on metabolism Benefits of certain AA Arginine- decrease tumor growth and metastatic rate in some rodents Glycine-shown to decrease cisplatin induced nephrotoxicity others as well…

Cancer’s effect on metabolism: 

Cancer’s effect on metabolism Lipid metabolism Some tumors cells have problems utilizing lipids as fuel source fats are usually last to be depleted type of lipid verses amount of lipid polyunsaturated n-3 fatty acids

Other important aspects of nutrients: 

Other important aspects of nutrients Vitamins- some evidence indicate might be helpful in cancer patients Retinoids, beta carotene, Vitamin C, D, and E Minerals- May be helpful Zinc, Cu, Se, etc…

Other ingredients: 

Other ingredients Fiber- insoluble and soluble Garlic- may help cancer patients Green/Black tea- Black tea may have soothing properties associated with radiation-induced oral mucositis. Shark cartilage-NO

Food Aversion: 

Food Aversion Food aversion- a common outcome of side effects of cancer and cancer treatments in humans Difficult to prove it occurs in animals

Therefore..Develop a feeding plan: 

Therefore..Develop a feeding plan What food to feed? How to feed the food? Monitor and reassess feeding plan constantly (Is the patient getting better)?

What food to feed?: 

What food to feed? Ideal diet would have minimal simple carbohydrates, fiber highly bioavailable protein with certain AA higher fat levels with polyunsaturated n-3 fatty acids adequate levels of antioxidants a great smell and taste great! Achieve with homemade diets or various commercial diets

Slide53: 

Canine products Hill's Prescription Diet Canine/Feline a/d, moist Hill's Prescription Diet Canine n/d, moist Hill's Science Diet Feline Maintenance Seafood Recipe lams Eukanuba Maximum-Calorie/Canine, dry lams Eukanuba Maximum-Calorie/Feline, dry lams Eukanuba Maximum-Calorie/Canine & Feline, moist Purina Feline CV-Formula, moist Table 25-5. Nutrient profiles of selected commercial pet foods that can be used in cancer patients.* Feline products Hill's Prescription Diet Canine/Feline a/d, moist Hill's Prescription Diet Feline p/d, moist lams Eukanuba Maxim um-Calorie/Feline, dry lams Eukanuba Maximum-Calorie/Canine & Feline, moist Purina Feline CV-Formula, moist Select Care Feline Development Formula, moist Products Protein Fat Carbohydrate n-3 fatty Arginine 45.7 38.8 45.1 40.1 44.2 43.3 28.7 32.0 25.4 29.0 29.6 41.1 16.5 20.0 20.1 22.7 19.1 7.6 2.6 7.2 0.82 0.9 0.93 0.78 2.04 2.9 2.83 na na 2.6 42.5 26.8 23.1 na na 45.7 48.8 44,2 43.3 28.7 31.5 29.6 41.1 16.5 11.1 19.1 7.6 2.6 0.42 0.93 0.78 2.04 2.66 na 2.6 Key: na = Information is not published by the manufacturer. *Nutrients are expressed on % dry matter basis. Values were obtained from manufacturers' published information. 42.5 48.0 26.8 32.2 23.1 12.1 na na na na

Feeding method: 

Feeding method Enhance palatability and aroma of the food whatever works Drug therapy- stimulate appetite Benzodiazepine derivatives (valium, oxazeoam) cyproheptadine Megestrol acetate

Feeding method: 

Feeding method Enteral route- preferred route of nutritional support vs. parental administration safer less expensive other physiologically beneficial effects

Enteral route: 

Enteral route Appropriate when: Appetite stimulating efforts fail or if long term nutritional support (more than a few days) is needed Can be used proactively inserted during surgery or before radiation therapy

Feeding method: 

Feeding method Parental nutrition- not covered here best reserved for cases in which patients are not able to assimilate nutrients or with intractable vomiting

Monitor feeding plan: 

Monitor feeding plan Monitor the effects of Cancer on patient Treatment and nutritional management of tumor Treatment and nutritional support on the patient --Check body weight, and body conditioning scores with previous assessments --Assess appetite and caloric intake

Quality of Life and Cancer: 

Quality of Life and Cancer How do you measure quality of life? As defined by the Veterinary oncologist at Animal Medical Center- five factors alertness/mental status appetite weight/body condition activity/exercise tolerance elimination

Measuring QOL cont..: 

Measuring QOL cont.. Is the patient enjoying painless and carefree days? Playing with his/her favorite toys or eating their favorite foods? Add your own measurement here:

Euthanasia: 

Euthanasia Should be discussed constantly with client Educate client on options Final human treatment

References: 

References Ettinger, Stephen, and Edward Feldman. Textbook of Veterinary Internal Medicine. 5th edition. Vol. 1. Philadelphia: W.B. Saunders Company, 2000. Nelson, Richard, and C. Guillermo Couto. Small Animal Internal Medicine. 2nd edition. Chicago: Mosby, 1998. Ogilvie, Gregory, and Antony Moore. Managing the Veterinary Cancer Patient. Trenton, NJ: Veterinary Learning Systems, Co., Inc., 1995. Schwartz, Cheryl. Four Paws, Five Directions: A Guide to Chinese Medicine for Cats and Dogs. Berkley, CA: Celestial Arts, 1996. Withow, Stephen, and E. Gregory MacEwen. Clincial Veterinary Oncology. Philadelphia: J.B. Lippincott Company, 1989.

Web Sites: 

Web Sites Comparative Oncology Research Exchange (CORE) at Cornell University http://www.web.vet.cornell.edu/index%5Finternet/cancer/index.html The Animal Medical Center http://www.amcny.org OncoLink at University of Pennsylvania Cancer Center http://www.oncolink.com Wing-n-Wave Labradors http://www.labbies.com/cancer3.htm#surgery Canine and Feline Cancer Links http://www.thensome.com/petcancer.htm#links

Slide64: 

Thank You! Any Questions?