cancer care in pets (veterinary oncology) orna kristal, dvm dip. american college of vet internal...
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Cancer Care in Pets(Veterinary Oncology)
Orna Kristal, DVMDip. American College of Vet Internal Medicine
(oncology)Chavat Daat, Beit Berl
Veterinary Specialty Training Requirements: DVM degree and internship Began in the US Today in Europe as well 3 yrs of working under supervision of
specialists in different fields Tumor biology studies Publication, presentations Specialty examination
Specialty in Veterinary Medicine
Large Animals (horses, ruminants) Internal medicine, Surgery, reproduction
Small Animals Internal Medicine, oncology, cardiology,
neurology Surgery Imaging Emergency medicine Ophthalmology, Dermatology, anesthesia Exotic animals (birds, reptiles, ferrets,
rodents) Pathology – clinical and histopathology
Cancer in dogs and cats No accurate incidence rates (IR) Dorn et al. 1968 – new cancer cases a
yr in 2 counties in CA Dogs – 382/100,000 Cats – 156/100,000 IR today probably much higher
Estimated lifetime risk of cancer Dogs – 50% Cats – 30%
Comparative aspects
Humans Dogs CatsBreast/prostate
Breast* Lymphoid
Lung Skin (non-melanoma)
Skin (non-melanoma)
Colorectal Sarcoma Breast*
Testicular (intact)
Sarcoma
Lymphoid, oral tumors
Genetic factors Golden Retriever
1 in 5 – Hemangiosarcoma 1 in 8 - Lymphoma
Boxer Lymphoma (T-cell)
Bernese Mountain Dogs Histiocytic Sarcoma
Scottish Terriers Transitional Cell Carcinoma
Sharpei High grade Mast Cell Tumors
Hormonal factors
Ovariohysterectomy Before 2.5 yrs of age in dogs and 1 yr
in cats is protective of mammary tumors
Castration Reduces risk of testicular cancer
Esp. in cryptorchids Increases risk of prostate cancer (still
uncommon)
Environmental factors - Dogs Exposure may be higher in indoor pets Exposure to passive smoke
risk for lung cancer – short and medium length nose (weak)
risk for nasal cancer – long-nosed breeds
Insecticides in shampoos or dips risk of TCC, esp. if obese But not spot-ons like Frontline or Advantage
Herbicides and insecticides on lawns risk of TCC in Scottish terriers
Environmental factors - Cats
Oral Squamous Cell CA (SCC) risk with:
High intake of canned food (RR – 3.6) and canned tuna fish (RR – 4.7)
Flea collar use (RR – 5.3) risk with flea shampoo use
Lymphoma risk with exposure to passive smoking
Why treat pets with cancer? Cancer is perceived by many to be a serious
and often fatal disease Treatment in people is commonly associated
with side effects leading to poor QOL Therefore treating pets with similar treatment is
perceived as cruel and selfish This perception represents total
misunderstanding of the treatment of cancer in animals
The main goal of treating animals with cancer is to extend a good quality of life for the patient (and family) for as long as possible.
What is QOL in animals? Life without pain & daily normal
activity Happy when owners come home, plays Wants to eat and drink Has control of eliminations
Quality is more important than quantity Life without QOL means prolonging
unnecessary suffering of the animal
How do we maintain QOL? We try to prevent treatment’s side
effects
Before treatment is begun risk vs. benefit is considered
Often animals treated for cancer live longer and better than animals treated for other chronic disease (i.e - diabetes, chronic renal or heart disease)
Maintaining QOL If the animal develops significant
treatment toxicity We can lower drug dosages Use other drugs Consider stopping treatment
Treatment can be with a curative intent or palliative
Know when to quit
Treatment modalities
Treatment options depend on Tumor type Location in body Tumor stage (TNM) Comorbidities
Treatment modalities Surgery Radiation therapy (not in Israel) Chemotherapy Small molecule
inhibitors (TKI’s) Cancer Vaccines
Melanoma Multimodality Tx Symptomatic Tx
Choosing the treatment Owners ultimately choose the
treatment after hearing Different options Prognosis for each option Possible side effects Cost
Should they choose not to treat, they are making an educated decision
Common signs of cancer in small animals
Abnormal swellings that persist or continue to grow
Sores that do not heal Weight loss Loss of appetite Bleeding or discharge from an opening
סימנים שכיחים של סרטן בחיות קטנות
Offensive odor Loss of energy, tire easily Persistent lameness Difficulty breathing, chewing, urinating,
defecating
Aural SCC
Baaci 7 yr old spayed female Golden Retriever
Baaci Presented with enlarged lymph nodes, fever,
unwell and diagnosed with lymphoma on cytology
Baaci With no treatment median survival is 4-6
weeks and QOL is poor most of this time. With CHOP based chemotherapy median
survival is extended to 12 months and about 25% are alive @ 2 yrs.
Drug dosages is lower than in humans. Only 20% develop grade 3-4 toxicity.
Baaci’s owner chose to treat with chemo.
Baaci
Achieved complete remission
Treatment continued for one yr
One episode of vomiting & diarrhea
requiring supportive care.
Still alive and happy today > 4 yrs from
diagnosis.
Chaos
4 yr old female Great Dane Diagnosed with osteosarcoma
(OSA)
Osteosarcoma Many similarities to human OSA
Affects large to giant breed dogs Metaphyses of long bones most affected Most stage negative at presentation 90% are high grade Common hematogenous lung metastases
Two main differences 10 times more prevalent in dogs Mean age
Dog – 7rs human – 14 yrs
Osteosarcoma Dogs
Are an outbred species Have innate immune system Their cancer progresses more rapidly
Combined with similarities in tumor behavior they can serve as an excellent model for research of this disease
Dr. Steve Withrow - pioneer in the field Clinical trials in dogs serve a dual
purpose
Chaos
Had forequarter amputation To control primary tumor and relieve pain
Post-operatively entered into a clinical trial 5 treatments with doxorubicin Followed by the oral trial drug vs. placebo
No side effects at all
Enjoyed an excellent QOL for 18 months after treatment
Median survival with amputation and chemo is 10 months
Slim, 7 yr old male Whippet Presented with unilateral nose bleed
from the left nostril (Sept 2008) CT and biopsy – left nasal
adenocarcinoma
Slim Treated with Radiation
12 X 4 Gy, 3 days a week Tumor shrunk by 30%, was stable for 2 yrs
then started growing very slowly Receives low dose prednisone permanently for
nasal congestion
Canine Mast Cell Tumors Common skin cancer Can be benign to malignant May swell up and shrink due to surges
of histamine release
Mast cell tumors Fairly easy to diagnose by cytology Biologic behavior highly correlated with
histologic grade Treatment depends on tumor grade and
stage
Targeted therapy for canine MCTTargeted therapy for canine MCT
Toceranib Phosphate(Palladia™)
KITPDGFRβVEGFR2Flt3
Masitinib Mesylate(Masivet®)
KITPDGFRFGFR3FAK (focal adhesion kinase)
33% of MCT express mutation in c-kit
In summary The main goal in treating animals with
cancer is good QOL for as long as possible
Every case should be evaluated individually
Owners should be given all options
The decision is theirs to make after weighing risk vs. benefit and cost
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