Cancer

Question 1

Hallmark: Sustained
Proliferative Signaling

Answer 1

• Uncontrolled cellular proliferation (replication)
• receptors activate intracellular activation of regulatory factors -> affecting DNA synthesis, entrance into the cell cycle, and changes in expression of other genes related to cell metabolism for optimal growth
• Basically receptors activate regulatory factors for optimal cell growth

Question 2

Hallmark: Evading Growth Suppressors

Answer 2

• secrete and increase growth factor
• Inactivation of Retinoblastoma Protein (Rb) Tumor Suppressor
• Activation of Protein Kinases That Drive The Cell Cycle
• Mutation In The TP53 Gene (Tumor suppressor Gene)

Question 3

Hallmark: Genomic Instability

Answer 3

3 causes:
- Activate Proto-oncogenes makes too much Oncogenes
- Mutation of genes that causes deactivation or suppression of tumor suppressors
- Mutation of genes that cause cell death thus allowing uncontrolled growth

Question 4

Oncogenes & Tumour- suppressor genes

Answer 4

Proto-oncogenes:
- normal genes for cell growth
Oncogenes:
* mutant genes
Tumour-suppressor genes
* proteins regulate proliferation (uncontrolled growth)
* anti oncogenes

Question 5

Hallmark: Replication Immortality

Answer 5

• cells can divide a limited number of times (Hayflick limit)
  Telomeres:
• protective caps on each chromosome

Question 6

Hallmark: Inducing Angiogenesis

Answer 6

• Angiogenesis = growth of new vessels. Also called neovascularization

Question 7

Hallmark: Avoiding cell death

Answer 7

• Programmed cell death (apoptosis) = cells can self-destruct
• TP53 gene incharge of apoptosis

Question 8

Hallmark: Avoiding Immune destruction

Answer 8

Immune surveillance hypothesis:
- most cancers are suppressed by an immune response against tumour-associated antigens
* cancer development = evasion of immune response
Immunotherapy hypothesis:
- predicts that the immune
system could be used to target tumour-associated antigens and destroy tumours clinically

Question 9

Hallmark: Tumour promoting inflammation

Answer 9

Chronic inflammation: Is an important factor in the development of cancer.
- wound-healing response that includes proliferation and new blood vessel growth

Question 10

What is Metastasis

Answer 10

Is the spread of cancer cells
from the site of the original tumour to distant tissues and organs through the body

Question 11

How Do Cancer cells Develop the ability To Invade (Locally) And
Metastasize?

Answer 11

• Most endothelial characteristics are lost, unable to adhere to basement membrane
• increases migratory capability
• Resistance to apoptosis (cell death) increases
• turns into stem cell = better growth in foreign microenvironments

Question 12

Cancer cells secrete protease, what does protease do?

Answer 12

Proteases digest the extracellular matrix and basement membranes.
= Create pathways through which cells can move

Question 13

Characteristics Of Cancer Cells

Answer 13

Anaplastic:
- very little resemblance to the cells they originated from
Pleomorphic:
- variable size, shape and structure
Substantial amount of stroma (microenvironment), but is disorganized with loss of normal tissue structure
Lacks a capsule
Capable of invading nearby structures

Question 14

Benign Vs. Malignant Tumors

Answer 14

• Benign
• Slow growth
• Well-defined
• capsule
• Not invasive
• Well differentiated
• Low mitotic index
• Does not metastasize
• Malignant
• Rapid growth
• Not encapsulated
• Invasive
• Poorly differentiated: Anaplasia
• High mitotic index
• Can spread distantly (metastasis)

Question 15

What is a stroma?

Answer 15

early and enlargement of the tumor = synthesis of proinflammatory mediators
* surrounds and infiltrates the tumor
* Stroma promotes cancer progression and metastatic potential

Question 16

What is Paraneoplastic syndrome?

Answer 16

-Symptom complexes are triggered by a cancer but are not caused by direct local effects of the tumour mass.
-Are caused by biologic substances released from the tumour (e.g. hormones) or by an immune response triggered by the tumour.
-Can be life-threatening (if serotonin is released)

Question 17

what are some Paraneoplastic Syndromes

Answer 17

Hypercalcemia
Hypoglycemia
Polycythemia (lotsof RBC’s)
CNS Disorders
Dermatomyositis
Clubbing of fingers
Anemia

Question 18

What is Cachexia?

Answer 18

-Is the most severe form of malnutrition
-Leads to protein-calorie malnutrition and progressive wasting
Manifestations:
-Anorexia, early satiety, weight loss, anemia, asthenia (abnormal physical weakness), taste alterations, and altered protein, lipid, and carbohydrate metabolism

Question 19

what is Thrombocytopenia?

Answer 19

Thrombocytopenia = abnormally lownumbers of platelets
* Platelet < 100,000/mm3.
* not at risk for spontaneous major bleeding unless below 20,000/mm3.

Question 20

what is Leukopenia?

Answer 20

Leukopenia = an absolute blood cell
count less than 4000 cells/μL.
* associated with a decrease in the
number of neutrophils, which
increases the risk for infection.
* The possibility for life-threatening
infections is high

Question 21

Stages of cancer

Answer 21

Stage 1
- Is confined to its organ of origin.
Stage 2
- Is locally invasive.
Stage 3
- Has advanced to regional structures.
Stage 4
- Has spread to distant sites.

Question 22

Explain the staging using the World Health Organization TNM system

Answer 22

TNM = Tumour node metastasis

T= Tumor
- t 1-4 indicates size of main tumor
N= Lymph nodes
- n 0 = has not spread to local lymph nodes
- n 1-3 = has spreed to lymph nodes
- n2-3 = size and how many lymph nodes
M= metastasis
- cancer has spread through the body
- m0= no spread
-m1= has spread

Question 23

Grading a tumour

Answer 23

Grade 1 (G1):
- Cells are differentiated and very similar to parent cells
* best prognosis
Grade 4 (G4):
- Cells are grossly abnormal and clearly different from normal
cells
* worst prognosis