oncology

Question 1

cell division

Answer 1

Not all cells divide at the same rate
Do not divide: Neurons, skeletal muscle cells
Divide slowly: Liver cells (once every 1-2 years)
Divide rapidly: GI epithelial cells lining GI tract (divide two or more times per day)

Question 2

Cell Proliferation

Answer 2

The process by which cells divide and reproduce.
Cells of body can be divided into three groups: Undifferentiated Stem Cells, Parent (“progenitor” cells), Well-differentiated Cells

Question 3

Undifferentiated Stem Cells

Answer 3

triggered to enter cell cycle & produce parent (progenitor) cells

Question 4

Parent (“progenitor” cells)

Answer 4

Continue dividing and reproducing, Examples: blood cells, skin cells, liver cells

Question 5

Well-differentiated Cells

Answer 5

Do not normally divide and reproduce
Examples: neurons and cells of skeletal & cardiac.

Question 6

What affects cell proliferation?

Answer 6

Speeds up in response to: Tissue injury, Tissue loss
In some cases, reproduction is normally repressed but it can also be triggered under certain circumstances: repair of liver damage.

Question 7

the cell cycle

Answer 7

The cell cycle is a sequence of growth stages that a cell moves through for mitosis and regeneration.
In order for cells to undergo mitosis, the cell must go through stages G0, G1, S, G2, and M.

Question 8

cell cycle phases

Answer 8

G0-cell at rest
G1- cell enter cycle, prepare for DNA replication, Proto-oncogenes, genes that control cell replication, are activated.
S- Synthesis of structures, move to opposite poles in preparation for division into two separate cells. 46 chromosomes reorganize as two separate sets of 23 chromosome.
G2- Cells prepare to divide
M- divison complete, 2 daughter cells created.

Question 9

Differentiation

Answer 9

the extent that neoplastic cells resemble normal cells both structurally and functionally.

Question 10

anaplasia

Answer 10

lack of differentiation
indicates total cellular disorganization, abnormal cell appearance, & cell dysfunction.

Question 11

what are tumor markers?

Answer 11

biologic substances, markers that shed off

Question 12

What type of substances are tumor markers?

Answer 12

hormones, enzymes, antigen, genes

Question 13

Where can tumor markers be found?

Answer 13

blood, urine, cerebral spinal fluid, tumor plasma membrane

Question 14

What are tumor markers useful for?

Answer 14

screening or diagnostic purposes
can help follow clinical course

Question 15

Are tumor markers diagnostic of cancer?

Answer 15

not always

Question 16

carcinogenesis involve 3 things, what are they?

Answer 16

genes
carcinogens
promoters

Question 16

4 phases of carcinogenesis

Answer 16

initiation
promotion
progression
metastasis

Question 17

Tumor Suppressor Genes

Answer 17

inactivated
Normally function to restrain cell growth.
Can also become defective and lose the ability to inhibit cell growth and division, thus allowing cancer formation.

Question 18

Proto-oncogenes

Answer 18

genes that stimulate and regulate a cell’s movement through the cell cycle, resulting in cellular growth and proliferation.

Question 19

oncogenes

Answer 19

proto-oncogenes become oncogenes that stimulate constant, unrelenting cellular proliferation and cell cycling.

Question 20

Carcinogens

Answer 20

Substances that cause development of cancer
Can alter cell DNA
Damage = cumulative!

Question 21

classifications of carcinogens

Answer 21

Known
Probable
Possible

Question 22

promoters

Answer 22

Agents that promote development of cancer
ex. Diet, Alcoholic beverages, Tobacco, Hormones.

Question 23

viral- induced cancer

Answer 23

Certain malignancies are associated with cancer-inducing viruses.
MOA - always involve the activation of growth-promoting pathways or inhibition of tumor suppressors in infected cells.

Question 24

primary tumor

Answer 24

is where the tumor begins

Question 25

secondary tumor

Answer 25

where it metastasizes too

Question 26

cancer spread

Answer 26

Seeding, Implantation & Metastasis