Cancer

Question 1

the cell cycle

Answer 1

-a sequence of growth stages that a cell moves through for mitosis and regeneration
-in order for cells to undergo mitosis, the cells must go through stages G0, G1, S, G2, and M

Question 2

stage G0

Answer 2

cell is at rest, and not actively engaged in the cell cycle

Question 3

stage G1

Answer 3

-cells enter the cell cycle and prepare for DNA replication
-proto-oncogenes are activated- genes that control cell replication

Question 4

stage S

Answer 4

-synthesis of structures occurs and the structures move to opposite poles in preparation for division into 2 separate cells. 2 nuclear membranes develop around the two separate sets of 23 pairs

Question 5

stage G2

Answer 5

cells prepare to divide

Question 6

stage M

Answer 6

mitosis is completed and two daughter cells are created

Question 7

cancer cells

Answer 7

-constantly moving through the cell cycle stages
-no checkpoints: no DNA errors recognized, and no apoptosis
-disregard the growth inhibitors released by neighboring cells
-as they proliferate, they accumulate on top, around, and beside each other, take over boundaries of organs, crowd out normal cells, and may even break free and travel to distant sites

Question 8

immune surveillance

Answer 8

-our immune system constantly surveys the body for foreign substances or non self antigens
-when a “non self” antigen is discovered, the immune system initiates an attack to destroy the invading substance
-with age, the strength of the immune system diminishes and tumor development becomes easier

Question 9

differentiation

Answer 9

-refers to the extent that neoplastic cells resemble normal cells both structurally and functionally
-lack of differentiation is called anaplasia, a term that indicates total cellular disorganization, abnormal cell appearance, and cell dysfunction

Question 10

benign tumors

Answer 10

-well differentiated, resembles tissue of origin
-progressive, slow rate of growth
-local invasion-cohesive cells, well demarcated tumor, often encapsulated making it movable
-no metastasis
-no necrosis in tumor core

Question 11

malignant tumors

Answer 11

-poorly differentiated; does not resemble tissue of origin
-erratic, slow to rapid rate of growth
-local invasion- invasive and infiltrating, surrounding normal tissue
-frequent metastasis
-can have necrotic core

Question 12

examples of tumor markers

Answer 12

-PSA
-BRCA

Question 13

tumor grades:

Answer 13

-grade 1: cells are well differentiated
-grade 2: cell are moderately differentiated
-grade 3: poorly differentiated or anaplastic cells

Question 14

TNM system

Answer 14

-T tumor size, location and involvement
-N-lymph node involvement
-M- metastasis to distant organs

Question 15

four stage classification system

Answer 15

-stage 1: confined to organ of origin
-stage 2: locally invasive
-stage 3: regional spread
-stage 4: spread to distant sites
-important component of cancer diagnosis

Question 16

4 phases of carcinogenesis

Answer 16

-initiation
-promotion
-progression
-metastasis

Question 17

tumor suppressor genes

Answer 17

-normally function to restrain cell growth
-can also become defective and lose the ability to inhibit cell growth and division, thus allowing cancer formation
-the P53 gene is the tumor suppressor gene in cells that controls cellular apoptosis

Question 18

proto oncogenes

Answer 18

-stimulate and regulate a cells movement through the cell cycle, resulting in cell growth and proliferation
-when mutated, proto oncogenes become oncogenes that stimulate constant, unrelenting cellular proliferation and cell cycling

Question 19

carcinogens

Answer 19

-substances that cause development of cancer
-can alter cell DNA
-damage=cumulative
-classification: known, probable, possible

Question 20

promoters

Answer 20

-agents that promote development of cancer
-examples: diet, alcohol, tobacco, hormones

Question 21

viral induced cancer

Answer 21

-certain malignancies are associated with cancer inducing viruses
-for any virus to live and propagate, it must insert its genes into the host cells genome
-the host cell then becomes a manufacturer of the virus
-MOA: always involve the activation of growth promoting pathways or inhibition of tumor suppressors in infected cells

Question 22

metastasis and angiogensis

Answer 22

-cancer cells are suited for this task because they secrete vascular endothelial growth factor, a substance that gives them the capability to develop new blood vessels

Question 23

metastasis: terminology

Answer 23

primary tumor- location- where did it start?
-secondary tumor- location- not original starting location

Question 24

cancer spread: seeding, implantation, metastasis

Answer 24

-seeding- intraperitoneal
-implantation- direct expansion of tumor to adjoining tissue
-metastasis: lymphatic and vascular

Question 25

lymphatic spread

Answer 25

-first stop is the lymph system
-cells trapped in lymph nodes
-3 possible scenarios- death, dormancy, flourish/proliferate

Question 26

vascular spread

Answer 26

-spread by vascular drainage- penetrate local veins
-first stop is often the liver

Question 27

secondary tumors

Answer 27

-need nutrients and oxygen
-need access to blood- angiogenesis (make own blood supply)
-most common: lungs, bone, liver, brain

Question 28

common metastatic sites

Answer 28

-lung- bone, brain
-colon- liver
-breast- bone, brain, liver, lung
-prostate- vertebrae
-melanoma-brain