L5- Cancer pathology

Question 1

what is neoplasia

Answer 1

abnormal and continuous growth of cells that have lost homeostatic control

Question 2

give 3 examples of carcinogens and the resulting cancer

Answer 2

1. asbestos (inhalation) = pleural mesothelioma in lungs
2. benzopyrene (cigarette smoke) = lung cancer
3. nitrosamines (salted fish) = nasopharngeal cancer

Question 3

give 5 causes of cancer

Answer 3

1. lifestyle & diet - high fat/red meat, obesity, smoking, alcohol
2. age
3. viruses/bacteria
4. radiation - ionising and non ionising
5. genetics

Question 4

how does neoplasia arise

Answer 4

cell with beneficial mutation/epigenetic change may continue to divide until a clone is formed (collection of identical cells). cells from this clone may acquire further genetic/epigenetic changes resulting in further growth.

Question 5

what is tumour heterogeneity

Answer 5

ongoing genetic/epigenetic changes after a tumour has been established may give rise to multiple subclones ( tumours within a single cancer) that have differing properties - determines metastatic potential and chemotherapy response (resistance).

Question 6

what are the characteristics of BENIGN neoplasms

Answer 6

non invasive 
well defined borders
well differentiated
regular nuclei 
rare mitoses

Question 7

what are the characteristics of MALIGNANT neoplasms

Answer 7

invasive/metastatic
poorly differentiated
irregular, larger nuclei
more frequent and/or abnormal mitoses

Question 8

what are the stages of colon cancer? Dukes classification

Answer 8

Duke’s A	        5 yr survival > 90%
Tumour limited to mucosa and submucosa 
Duke’s B         5 yr survival	55% to 85%
Extension to all layers- mucosa, submucosa, muscularis, serosa   
Duke’s C        5 yr survival 20% to 55%
Metastases to regional lymph nodes 
Duke’s D       5 yr survival < 5%
Distant metastases to lungs and liver

Question 9

what does the grade of cancer refer to or tell you about a cancer?

Answer 9

grade- degree of similarity to tissue of origin (essentially how bad do the cells look)
grade 1 = cells well differentiated (similar to normal tissue)
grade 2 = moderately differentiated
3 = poorly differentiated
4 = anaplastic (completely different to normal tissue)

Question 10

define TNM staging of cancer

Answer 10

T - tumour size
N - nodes, how many?
M - metastases, has it/not?