Lecture 1 - Cancer Biology and Approach to the Cancer Patient (Dr. Burge)

Question 1

• Closely controls cell growth and division
• Function is to duplicate DNA and divide it into two daughter cells
• Stress or DNA damage generally results in cell cycle arrest or apoptosis
  This is describing…

Answer 1

The Cell Cycle

Question 2

Definition:
- A normal gene that is involved in cell growth proliferation
- If the_______________ is activated due to a mutation in the DNA, this causes continuous cell growth and division and leads to cancer formation

Answer 2

proto-oncogene (accelerator)
- cancer development

Question 3

Definition:
- Are genes that normally act to inhibit cell proliferation and tumor development
- If the _________________ is inactivated due to mutations in the DNA, this can lead to continuous cell growth and division -> leads to cancer formation

Answer 3

Tumor Suppressor Genes (braking system)

Question 4

What is the most famous tumor suppressor gene?

Answer 4

p53
- guardian of the genome

Question 5

What is the following?
- Only need mutation in ONE allele to cause ACTIVATION

Answer 5

Oncogenes
- Dominant gain of function

Question 6

What is the following?
- Needs mutations in BOTH alleles to cause INACTIVATION

Answer 6

Tumor Suppressor Genes
- Recessive loss of function

Question 7

List the Hallmarks of Cancer:

Answer 7

• Genome instability & mutation
• Resisting Cell Death
• Sustaining proliferative signaling
• Evading growth suppressors
• Avoiding immune destruction
• Enabling replicative immortality
• Activating invasion and metastasis
• Tumor-promoting inflammation
• Inducing angiogenesis
• deregulating cellular energetics

Question 8

Chemical Risk Factors:
Exposure to environmental tobacco smoke increases the risk of …

Answer 8

• Feline lymphoma
• Canine nasal tumors, lymphoma

Question 9

Chemical Risk Factors:
Pesticides increase the risk of …

Answer 9

• Urothelial Carcinoma in Scotties when exposed to 2,4-D treated grass
• associated with canine lymphoma development
• Oral squamous cell carcinoma in cats

Question 10

Physical Risk Factors:
Sunlight (UV-B) exposure increases the risk of …

Answer 10

• Facial, aural, and nasal planum SCC in cats
• Cutaneous hemangiosarcoma (HSA) in dogs

Question 11

Viral Risk Factors:
What is associated with Lymphoid cancers?

Answer 11

Feline Leukemia Virus (FeLV) - oncornavirus

Question 12

Viral Risk Factors:
What is associated with lymphoid and myeloid neoplasia?

Answer 12

Feline Immunodeficiency Virus (FIV) - lentivirus

Question 13

(T/F) Cats infected with FIV and FLV are 5.6x more likely to develop lymphoma or leukemia than if they had been infected with either virus alone

Answer 13

True

Question 14

Obtaining a Diagnosis - Cytology
Pros:
- Non-invasive/low risk
- Low cost
- No anesthesia/sedation is required
- Quick turnaround time
- Supplies readily available
- Often allows for tumor categorization
- Diagnostic for SOME tumors
Cons:
May be insufficient for a definitive diagnosis

Answer 14

Fine needle aspirate (FNA) and cytology

Question 15

Definition:
Obtaining tissue specimen for histopathology

Answer 15

Biopsy

Question 16

What is the most common site for distant metastasis?

Answer 16

Lungs

Question 17

Where is it? - evaluating lymph nodes
Lymph node evaluation is important for tumors that commonly metastasize via lymphatics:

Answer 17

• Epithelial tumors (carcinomas)
• MCTs
• Melanoma

Question 18

Definition:
The first lymph node to which cancer cells are most likely to spread from a primary tumor

Answer 18

Sentinel lymph node