Cancer

Question 1

features of a benign neoplasia (4)

Answer 1

slow growth, often well circumscribed, well differentiated cells, unable to metastisize

Question 2

features of malignancy (6)

Answer 2

locally invasive, destructive growth, poorly circumscribed, often induce desmoplasia(connective tissue growth) to stroma, variable differentiation (well, moderate, poor, anaplastic), potential to metastisise

Question 3

3 ways for metastises to spread

Answer 3

lymphatic, haematogenous and transcoelomic

Question 4

compared to normal cells, neoplastic cells tend to demonstate? (2)

Answer 4

cytological atypia and architectural disorganization

Question 5

give 6 examples of cytological atypia. how does this differ from benign

Answer 5

larger nuceli, pleomorphic(many shapes) nuclei, coarser nuclear chromatin, hyperchromatic nuclei, larger more prominent nucleuoli, abnormal mitotic divsion.Benign have less atypia

Question 6

basis of tumour terminology (excluding exceptions)

Answer 6

prefix denotes lineage (eg adeno for gland).Suffix for benign is oma.Malginant: carcinoma = epithelial. sarcoma = mesenchymal

Question 7

whats deoes leiomyo denote?

Answer 7

smooth muscle

Question 8

what do grade and stage refer to in grading?

Answer 8

grade = differentiation and stage = size

Question 9

4 main types of cancer. difference in treatment

Answer 9

Non small cell Carcinoma - SCC, adenocarcinoma, large cell (undifferentiated) carcinoma.Small cell Carcinoma.Small cell needs chemo, rest removed surgically

Question 10

3 ways mutations occur. give examples where appropriate

Answer 10

carcinogenic agents (chemicals, smoking, UV light, Radiation, Viruses/Bacteria).Inherited - (TSG p53 abnormality, defective DNA repair)Normal mistakes made in normal DNA replication not being repaired

Question 11

what is the only example of a single gene cancer. Explain.

Answer 11

retinoblastoma.gene is a tumour suppressor gene. A cell can function normally with only one functional copy of a tumour suppressor gene. In this case of one mutant copy of the gene is inherited and the second copy mutates after birth in one cell i.e. there is loss of heterozygosity. The affected cell can then start to profilerate abnormally, as there is loss of suppression of cell division.

Question 12

4 classes of genes are principally involved in mutations that cause cancer. what are they?

Answer 12

growth promoting proto-oncogenesGrowth inhibiting tumour suppressor genegenes that regulate apoptosisgenes that regulate DNA repair

Question 13

dif b/w proto-oncogenes, oncogenes and oncoproteins?

Answer 13

PO = normal genes that promote cell proliferation.Oncogenes = mutant proto-oncogenes that function autonomously - dont need growth signalling.Oncoproteins - proteins encoded by oncogenes

Question 14

what is TSG p53. what are its functions (3)?

Answer 14

Tumour suppressor Gene - guardian of the genome.its function is to Respond to particular cellular stress via - DNA Repair, apoptosis, cell cycle arrest