Neoplasia Flashcards
What is neoplasia
Cancer
Uncontrolled cell growth
Transformation wit neoplasia is
This is how we describe a cell that can no longer control its own growth
The cell continues to replicate
Continued replication results in a neoplasia
What are the 3 causes of cell transformation into cancer
Genes that start cell replication are turned “ON”
Genes that stop cell replication are turned off “OFF”
More growth factors
What are genes with transformation altered by
Spontaneous mutation
Inherited mutation
DNA damage (UV light, radiation, chemicals)
Specific viruses - FeLV
How does transformation cause neoplasia
When a population of transformed cells results in abnormal tissue growth
In other words, the transformed cells snuck by the immune system and took off
What is a tumor
Population of well organized neoplastic cells
Grows into a “mass”
No way of knowing what type of mass it is just by looking at it
What does benign mean
Local; non invasive
Does not interfere with normal tissue function
Does NOT spread
“-oma”
What does malignant mean
“Cancer”
Will grow into surrounding; healthy tissue; invasive; destructive
Interferes with normal function
Can spread
“-sarcoma”,”-carcinoma”
Metastasis is
When a cancer spreads from its original location to distant locations
Property of some, but not all, cancers
Movement of cells via the blood or lymphatics
Produces secondary tumor sites
Lungs, liver, lymph nodes most common
Always a poorer prognosis
Common signalment of neoplasia
Older animals are at an increased risk of developing neoplasia
Due to accumulation of damage to DNA
Cachexia is
Chronic loss of body condition associated with severe chronic inflammation or cancer
One of the few clinical signs that is consistent with most cancers
Other clinical signs vary depending on tissue affected ad if benign/malignant/metastatic and degree of inflammation
How to diagnose cancer
FNA+cytology
excisional biopsy
What is an excisional biopsy
Surgical removal for diagnostic purposes
Gold standard
What is staging when it comes to neoplasia
A series of procedures that are carried out to provide information about cancer in a particular patient
To aid in the development of a treatment plan and prognosis
Staging answers what questions for neoplasia
How big
How fast is it growing
How much tissue destruction is ti causing
Metastasis
What are some ways to treat cancer
Surgical excision
Chemo
Radiation
Any combination of the above
What is surgical excision for neoplasia
Cutting it out
Tumor
Removal of the entire affected tissue/organ
Clean margins
Debulking
What is chemotherapy
Systemic drugs that target rapidly growing cells
Including bone marrow stem cells, immune cells
Best option if metastasized
How does radiation therapy work
Targeted radiation beam
Radiation damages DNA until cells cannot replicate
How do you choose treatment for cancer
Try to remove as much of the tumor as possible
First attempt ideal
Supportive care
Benefit vs risks
Metastatic vs local
Humane euthanasia is a form of treatment
Supportive care for neoplasia is
Pain control
Anti Inflammatories
Appetite stimulants
GI protectants
Cardio-protectants, antihistamines, supplements, splints, braces, nutrition, physical therapy, oxygen
Palliative care with neoplasia includes
Treating the clinical signs without addressing the primary problem
Type of end of life care for cancer and other terminal diseases
Primary concern is quality of life
May include surgery, radiation, chemotherapy, supportive or adjunctive therapies
What is the prognosis with benign neoplasia
good
What is the prognosis with malignant neoplasia
poor
What is the prognosis with metastatic neoplsia
guarded
What does median survival time mean
Estimate of duration of life; how long the median animal survives in a given population
How long dog #50 out of 99 lived
Endpoint is death due to disease
Includes euthanasia and death from disease
Will walter depending on choice of treatment
Lipomas are
A fatty tissue collected just bello the skin
Can be fully excised
Lymphosarcoma is and common in
Malignant, metastatic neoplasia of the lymphocytes
Dogs- usually older animals
Golden retriever, basset hound, st bernard, bernese mountain dogs (the “cancer” breeds)
Can see in young and old cats
The only cancer that is considered an emergency for purposes of rtreating
Lymphoma in cats is and common in
Seen in two distinct populations
Young cats – often FeLV +’ve
Older cats
Kidneys, GIT, spleen, liver, lymph node and bone marrow involvement
Cats with FeLV and FIV are at a higher predisposition of developing lymphosarcoma
Treatment with chemotherapy
Where can lymphosarcoma be present
Submandibular
Prescapular
Axillary
Inguinal
Popliteal - back of thigh
How to treat lymphosarcoma
University of madison- wisconsin protocol
-Multi-drug chemo treatment
-Very expensive
-MST from diagnosis is 12-14 mo remission
Single drug chemo
-Can be done in many general practices
-MST from diagnosis is 5-8 mo
Immunosuppressive prednisone therapy
-Safer; not a chemo drug
-MST from diagnosis is 2 mo
No treatment
- +/- palliation
- MST from prognosis is less than 1 mo
Mast cell tumor is
the great mimicker”
Mast cells
Normal and transformed cells can look the same
How to grade mast cell tumors
1
- Slow growing, local
-Can be resected and “cured” if local
2 (lo)
- Similar to 1
2 (hi)
- May have local spread
- Can be resected; usually risk of metastasis
3
- Severe, rapidly growing and likely metastasized
- Radiation +chemo; usually has a poor prognosis
What is hemangiosarcoma
Common in dogs
Cancer of the blood vessel endothelial cells
Weakens the wall → stretches → risk of rupture
Can happen anywhere there are blood vessels
Spleen
Right atrium
SQ
Risk of metastasis?
What happens to patients with hemangiosarcoma
Risk of bleeding
Treatment of hemangiosarcoma
Often do not show clinical signs until a bleeding episode
Can bleed out
Lethargic, pale mm, distended abdomen, fluid wave, shock
Shock rates of IVF
Splenectomy – often palliative
Blood transfusion
What happens in right atrium hemangiosarcoma
Weakened atrial wall
Leak or burst
Bleeding into pericardial sac
Pericardial effusion
Ventricular fibrillation
Cardiogenic shock
Osteosarcoma is
Malignant bone tumor
Long bones are more commonly affected
Tibia, femur, humerus, radius
Bony mass
Lameness
Pathological fracture
Metastasis (over 90%)
Feline injection site sarcoma is
Sarcoma = cancerous neoplasia of fibrocytes
Associated with injections
Adjuvants
FeLV vaccine
Killed rabies vaccine
1/1 000 - 1/10 000 injections
Delayed appearance (weeks to years after injection given)
Genetic predisposition?
What are the characteristics of feline injection site sarcomas
Aggressive → locally invasive
Moderate risk of metastasis
Typically occur where the injection was given
Diagnosis of feline injection site sarcoma
Presentation: mass on cat
Histopathology
How to treat feline injection site sarcomas
Surgical excision
CT scan/MRI followed by surgical excision with wide margins
What was the thought of what to do with feline injection site sarcomas in the 90s
Hypothesis
- Vaccine injections in the scruff cause sarcomas to occur at the scruff
Problem
- Cannot resect due to deep tissue invasion
Recommendation
- Give vaccine sin distal limb
- Rabies (RHSQ): FeLV(LHSQ); FVRCP(LFSQ)
What is the new thoughts about injection site sarcomas
New hypothesis
- Tumors are triggered by injections
- No longer just vaccinations implicated
Result
- Need to record location for all injections in case of adverse reactions
Decreasing the risk of feline injection site sarcomas
Vaccinate cats based in risk for that cat
Always record site and route of vaccine administration, avoid IM injections
Identify “lumps” on cats
Report vaccine reactions to manufacturer
Do not vaccinate cats previously diagnosed with injection site sarcomas
When is testicular tumors common
Cryptorchid
Inherited
Certain breeds
Abdominal and inguinal equally likely
5% of dogs with retained testicles develop neoplasia
All species
Middle aged
What causes testicular tumors
Different types of cells can transform
Metastasis is uncommon - <15% for sertoli cell tumors and seminomas, less for interstitial cell tumors
Prevention of testicular tumors
How to prevent
NEUTER, especially if cryptorchid
Do not breed cryptorchid animals
Cryptorchidism is inherited
Signalment of mammary neoplasia
Intact bitches/queens
Animals that were spayed later in life
Risk increases with age
Pathology of mammary neoplasia
Higher estrogen/progesterone levels
Stimulates cell growth
What does mammary neoplasia look like
Multiple
Mixed tumors
Dogs 50% malignant
Cats 90% malignant
>50% metastasized
Masectomy is needed
What are the post op complications with mammary neoplasia
LOTS
Increased bleeding
Inflammation
Wound tension
Dehiscence
Pain
Infection
Dedicated follow up and nursing care
How. much risk are bitches to get mammary neoplasia
¼ to 1/20 intact mature females
Spay before 1st estrus decreased 99.5%
1st and 2nd estrus decreased 92%
2nd and 3rd estrus decreased 60-75%
After 3rd estrus not significant
