UNIT 8: NEOPLASIA

Question 1

Normal cell cycle

Answer 1

• growth factors control cell division

- cell cycle monitored at every checkpoint by cyclins

Question 2

Differentiation

Answer 2

• grown-up cells look different from one another
• stop dividing
• anchored to extracellular matrix by anchoring proteins
  - if lose anchorage then destroyed by apoptosis

Question 3

Cancer

Answer 3

• causes by genetic mutations as a result of
  
  1. exogenous factors
     2. endogenous factors

Question 4

Endogenous factors

Answer 4

1. Proto-oncogenes get mutated into ongogenes
   - caused by infection and therefore overproduction of proteins
2. tumor suppressor genes -> normally stop division of mutated cells, but if mutated then increase division etc

Question 5

Carcinogenesis

Answer 5

development of cancer

1. initiation = initial mutation
2. promotion = mutated cells divide
3. progression = tumor cells compete with on another and develop more mutations

Question 6

Benign tumors

Answer 6

• slow dividing
• contained within capsule
• dont invade neighboring tissues
• resembles normal tissue
• well differentiated

Question 7

Malignant tumors

Answer 7

• rapidly divide
• undifferentiated
• not defined, branch off
• dont resemble normal cells
• fast growing
• necrotic core
• can destroy surrounding tissues
• often hemorrhages
• high pleiomorphism

Question 8

Metastasis

Answer 8

• cells escape and travel in blood
• occurs in lymphatics or within body cavity too
  Need to:
• digest blood vessel wall
• survive in bloodstream
• attach to new tissue
• grow

Question 9

Organ tropism

Answer 9

• tumor cells typically metastasize to preferred sites

Question 10

clinical manifestations of cancer

Answer 10

1. changes in organ function
2. local effects of the tumor (bleeding, compression)
3. Ectopic hormones secreted by tumor cells (secrete hormones typically produces elsewhere)
4. nonspecific signs of tissue breakdown (weight loss, atrophy, weakness, anorexia, anemia)

Question 11

Tumor grading

Answer 11

• classifies tumors according to histological features (inversely related to differentiation of cells)

Question 12

Tumor staging

Answer 12

• classifies according to size, invasiveness and spread

- TNM system: T= size of tumor, N= presence of lymph node metastases, M = metastases in other organs

Question 13

tumor markers

Answer 13

• molecules that indicate presence of tumors

Question 14

Treatment strategies

Answer 14

1. surgery
2. radiation = kills what is left behind
3. chemotherapy = antiangiogenics
4. immunotherapy = remove inhibition of immune system, attach chemicals to certain antibodies against tumor cells