Cancer

Question 1

What is a point Mutation?

Answer 1

Known as a single base substitution.

Causes the replacement of a single base nucleotide of the genetic material, DNA or RNA

Question 2

What are the Different Types of Cancer?

Where do they Arise from?

Answer 2

1. Carcinoma–> Epithelial/Squamous tissue
2. Sarcoma–> Connective Tissue
3. Adenocarcinoma–> Ductal/Glandular
4. Lymphoma–> Lymph tissue
5. Leukemia–> Blood

Question 3

Give Examples of Each Cancer Type

Answer 3

1. Carcinoma–> Conjunctiva (Eye)
2. Sarcoma–> Vastus Lateralis
3. Adenocarcinoma–> Papilla of Vater & PANCREAS
4. Lymphoma–> Non-Hodgkin’s
5. Leukemia–> B-cell Acute Lymphoblastic

Question 4

Define Cancer

Answer 4

1. A Malignant Tumor is a tissue overgrowth
2. Independent from the laws that govern normal cells
3. Neoplasm overgrowth serves no useful purpose
4. Benign Tumors Are NOT Considered Cancer

Question 5

Define Neoplasm

Answer 5

“New Growth”

Any swelling due to Inflammation

Question 6

What are the Properties of Benign Tumors?

Answer 6

1. Slow Growth
2. Have a well-defined capsule
3. Not Invasive
4. Not Differentiated
5. Low Mitotic Index
6. Does not Metastasize

Question 7

What are the Properties of Malignant Tumors?

Answer 7

1. Rapid Growth
2. Not encapsulated
3. Invade Local Structures & Tissues
4. Poorly Differentiated
5. High Mitotic Index
6. Can metastasize

Question 8

How Does Cancer Develop?

Answer 8

Multi-Factoral:

1. Genetically
2. Chemically
3. Environment
4. Viral/Immunologic
5. Causes yet undefined

Question 9

How Many Changes in a Gene of DNA are Required for Cancer to develop?

Answer 9

@ Least 4–5 changes over many years.

“Hits”

Question 10

What are Tumor Cell Markers?

Answer 10

1. Substances that are present in Benign & Malignant Tumors.
2. Can be found In, On the Tumor or in the Blood, Spinal Fluid, or Urine.
3. These Substances Include:
   a. Hormones
   b. Enzymes
   c. Genes
   d. Antigens
   e. Antibodies
4. Ex: AFP, PSA, CEA

Question 11

What Are Tumor Markers Used For?

Answer 11

1. Screen & identify individuals @ high risk for cancer
2. Help Dx specific type of tumor in individuals c clinical manifestations
3. Follow clinical course/determine efficiency of treatment

Question 12

What do Cycline Dependent Kinases do?

Answer 12

They control check point transitions between phases in the cell cycle

Question 13

Do Cancer Cells Enter the Cell Cycle?

Answer 13

1. Frequently
2. Found mostly in
   a. Synthesis
   b. Mitosis
3. They DO NOT spend much time resting

Question 14

What do cancer cells do to the cell cycle?

Answer 14

1. Alters cell cycle
2. Growth Factors signal outside the cell that may ignite the cell cycle
3. Activates transmembrane proteins (Tyrosine Kinase) allowing signal transduction for DNA Replication!!

Question 15

Anaplasia

Answer 15

1. Lost ability of a cell to differentiate or resemble the original cell
2. Usually found on Malignant Tumors
3. Difficult to tell where cancer originated bc they typically look like other cancer cells not from the tissue they originated.

Question 16

What are Characteristics of Cancer Cells?

Answer 16

1. Autonomy: Lack contact inhibition; Decrease need for external Growth Factor
2. Anchorage Independent: Can continue to grow s being attached to anything(floating)
3. Immortal: Unlimited Lifespan; Continues to divide
4. Anaplasia: No differentiation = No control of growth
5. Pleomorphism: Variable Size & Shape!

Question 17

How do cancer cells change the host cell?

Answer 17

1. Cell Membrane:
>Fibronectin
>Changes cell organization
 >Structure, Adhesion, Migration
2. Permeability of cell is altered
3. Density/cell shape
4. Communication
5. Cytoskeleton 
>Protein filament network
>Shape & Movement

Question 18

Fibronectin

Answer 18

A glycoprotein that holds cells in place

Question 19

Oncogenes

Answer 19

1. Encode proteins that promote normal growth.
2. Overexpression or Amplification causes gain of function (Abnormal)
3. Oncogenes can transform Normal Cells to Cancer Cells!!
4. In normal state they regulate healthy proliferation

Question 20

Pre-Oncogene

Answer 20

A normal gene that regulates normal growth & development by encoding for growth factor & growth factor receptors

Question 21

Tumor Suppressor Gene

Answer 21

Encodes proteins that inhibit proliferation (Abnormal Growth) & prevents or repairs mutations

Question 22

Telomere

Answer 22

1. Are @ the ends of each chromosome blocking/inhibiting cell division
2. Telomerase maintains telomeres.
3. Cancer cells activate telomerase to DEACTIVATE talomere so they can continually divide

Question 23

Additional Changes in the Cell that Result in Cancer

Answer 23

1. Point Mutations
2. Chromosome Translocation
3. Gene Amplification
4. Loss of Heterozygosity
5. Epigenic Silencing

Question 24

What is Angiogenesis?

Answer 24

1. New Blood Vessel Growth
2. Cancer Cells produce angiogenic growth factors.
3. Advanced cancers can secrete several factors that stimulate new blood vessel growth
4. They initiate proliferation of existing blood vessels which allows small cancer to grow LARGE

Question 25

How are cancers so strong?

Answer 25

1. Self-sufficient in growth signaling 2. Insensitive to Anti-growth signals 3. Evades Apoptosis 4. Limitless replicative potential 5. Sustains angiogenesis 5. Ability to Metastasize

Question 26

Inflammation & Cancer

Answer 26

1. Inflamed cells release Cytokine & activate free radicals which promote mutations 2. ** Inflammation turns ON ONCOGENES** 3. Over time results in the wrong cells getting growth factors needed to grow and develop

Question 27

Growth Factors

Answer 27

Signals outside of the cell that initiate the cell cycle

Question 28

Virus's that cause cancer

Answer 28

1. Epstein-Barrvirus--> Burkitt's Lymphoma 2. HIV--> Kaposis Sarcoma 3. Hep B--> Hepatocellular carcinoma 4. HPV--> Squamous cell Carcinoma

Question 29

Bacterial causes of cancer

Answer 29

Helicobactor Pylori: 1. Peptic Ulcer Disease 2. Gastric Lymphomas 3. Gastric Carcinomas

Question 30

Characteristics of Angiogenesis

Answer 30

1. A tumor could not grow > 2--3mm^2 s new blood supply | 2. Provides a mechanism of nutrition & escape from original site

Question 31

In order for Metastasis to occur...

Answer 31

You need the right cell (seed) & the right Organ (soil) in which to grow

Question 32

Contact Inhibition

Answer 32

1. The cancer cells continue to grow & crowd eventually piling up on each other like a traffic jam/accident. 2. Normal cells must be attached to a surface, cancer cells do not

Question 33

Cancer Immortality

Answer 33

1. Normal cells may only divide 10--50 times in their lifespan 2. Cancer cells have an unlimited lifespan & will continue to divide for years

Question 34

Tx of Cancer: Chemotherapy

Answer 34

1. Most cytotoxic drugs work by disrupting DNA 2. They affect any cell that is dividing rapidly @ that time: a. Bone Marrow b. Hair Follicles c. Mucosal Cells

Question 35

What are the affects of Chemotherapy?

Answer 35

1. Immediate: a. Extravasation-CA enters organs b. Hyperkalemia c. Hyperphosphatemia d. Hypocalcemia e. Renal Impairment 2. Acute--Post Chemotherapy (W/I 24hrs) a. N/V 3. 10--14 days p administration: a. Blood count falls b. Mouth ulcers occur c. Taste changes d. Diarrhea 4. Months on Chemotherapy: a. Heart & Kidneys are affected 5. Late Toxicities: a. Infertility b. Early Menopause

Question 36

Important Electrolytes to track c a pt on Chemo

Answer 36

1. K+--> Hyper = >5 2. Phos-->Hyper =>4.5 3. Ca++--> Hypo <8.5

Question 37

Radiotherapy for Cancer pt

Answer 37

1. Damages or Kills ALL cells in a specific area 2. Tx for 6 wks 3. Tx must be limited bc it affects normal cells too. 4. Can cause localized & systemic effects