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 Increasing Incidence 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 an Adjunctive 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 an Adjunctive 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?