Cancer 1

Question 1

What is incidence and prevalence?

Answer 1

Incidence: the # of new dx cases per year

Prevalence: the total # of dx cases

Question 2

Most common cancer occurring in men? Women?

What is the cancer both genders are likeliest to die from?

Answer 2

Men: non-melanotic skin cancer

Women: breast cancer

Lung cancer = highest mortality

Question 3

Role of p53?

Answer 3

Phosphoprotein activated by DNA damage; arrests the cell cycle (inhibits G1-S) to allow the damage to be repaired or promote apoptosis

Question 4

Role of Rb?

Answer 4

When hypophosphorylated, it inhibits G1-S

When mutated, can cause retinoblastoma

Question 5

When is a tumor considered malignant?

Answer 5

When the tumor cells invade surrounding tissues and establishes secondary areas of growth (metastasis)

Question 6

Tumor clonality

Answer 6

Tumor initiation from a single cell that proliferates abnormally

Has the same X-inactivation pattern

Question 7

What are is characteristic of cancer cells?

Answer 7

Tumor clonality, genetic instability, anchorage independent, “immortal,” loss of contact inhibition, avoid apoptosis, angiogenesis, invasive, metastasis

Question 8

What is a direct cancer? Indirect cancer?

Answer 8

Direct: cx that arises due to an inherited mutation in an oncogene or TS gene (ex: BRCA, APC)

Indirect: cx that arises due to defective DNA repair (ex: XP)

Question 9

What is the 3 stage model of cancer?

Answer 9

1. Initiation (change in DNA)
2. Promotion (clonal expansion)
3. Progression (-> metastasis)

Question 10

What are direct-acting and indirect-acting carcinogens?

Answer 10

Direct-acting: electrophilic compounds that react with DNA

*Indirect-acting: DNA adducts are formed (Benzo-a-pyrene in tobacco smoke, for instance)