Introduction

Question 1

Definition

Answer 1

heterogeneous group of diseases where single cells acquire ability to proliferate abnormally - accumulation of progeny
tumours acquired ability to invade surrounding tissues

Question 2

Carcinoma

Answer 2

epithelial

Question 3

Sarcoma

Answer 3

mesoderm

Question 4

leukaemia/lymphoma

Answer 4

blood cell precursor

Question 5

benign

Answer 5

localised, non-invasive

Question 6

malignant

Answer 6

invasion and metastasis

Question 7

benign —> malignant

Answer 7

progression

Question 8

Angiogenesis

Answer 8

formation of new blood vessels

Question 9

Rate limiting step in growth

Answer 9

every cancer cell needs to be within 1mm of blood supply

Question 10

Metastasis

Answer 10

leave initial site and transit to distant sites via blood/lymph and body cavities

Question 11

Malignant melanoma can travel to

Answer 11

brain and liver

Question 12

intravasation

Answer 12

into vessel

Question 13

Mutation

Answer 13

stably inherited change in genetic material

Question 14

Evidence for genetic basis

Answer 14

inheritance
sporadic mutations are transforming
chromosomal changes common - particular to cancer
agents damage DNA —> increase cancer risk
diseases from DNA defects —> increase cancer
infection certain viruses —> development cancer

Question 15

Tobacco smoke responsible for

Answer 15

20-30% cancers

Question 16

Types mutation

Answer 16

Chromosome number change - ploidy change
translocations
amplifications
interstitial gains and losses
small deletions/insertions and single base pair muatations
exogenous sequences - viruses in cervical cancer HPV, burkitts lymphoma EBV, hepatocellular carcinoma hepatitis, kaposi’s sarcoma HIV
epigenetic mechanisms - promoter hypermethylation, inherited as cells divide

Question 17

Cancer is rare at cell level due to

Answer 17

DNA repair mechanisms (highly evolved)
apoptotic mechanisms
mutations usually not affect growth
most DNA not code protein
rapidly dividing cells (skin) lost so not matter if mutations
many cells lose potential to divide after differentiation
single mutation not escape defences

Question 18

Mutation increase growth, division, survivial

Answer 18

expand population for subsequent mutations (bigger target)

Question 19

mutation alter genomic stability

Answer 19

increase mutation rate and susceptibility to further mutations, 2nd mutation not repaired

Question 20

oncogenes normal role (proto-oncogene)

Answer 20

promote proliferation, growth, invasion

Question 21

oncogene gain of function

Answer 21

1 allele - excessive/inappropriate activity

Question 22

Tumour suppressor normal

Answer 22

inhibit events leading to cancer, inhibit and slow growth

Question 23

tumour suppressor loss of function

Answer 23

2 alleles - inactivation and cancer development

Question 24

Gatekeeper

Answer 24

control proliferation

Question 25

caretaker

Answer 25

control rate of mutation

Question 26

adenoma

Answer 26

benign tumour

Question 27

Feature of cancer development

Answer 27

order mutations important

Question 28

Hanahan and Weinberg principles

Answer 28

Independence of external growth signals
insensitivity to external anti-growth signals
avoid apoptosis
indefinite replication
angiogenesis
metastatsis/invasion