properties of cancer (W13)

Question 1

epithelial malignancy name?

Answer 1

carcinoma

Question 2

which part of an ulcer should you biopsy

Answer 2

the edge

Question 3

appearances of surface neoplasms?

Answer 3

plaque, ulcerated, annular, pedunculated polyp, papillary, exophytic/mass forming

Question 4

difference between polyp and papillary

Answer 4

polyp - epithelium covers raised core
papillary - epithelium covers thin branches. greater surface area but same size

Question 5

name for neoplasm with connective tissue stalk?

Answer 5

pedunculated

Question 6

name for neoplasm without connective tissue stalk?

Answer 6

sessile

Question 7

benign neoplasms - how do they cause problems?

Answer 7

compression
obstruction/intussusception
haemorrhage, infarction
secreted products
progression to malignancy
cosmetic
local trauma/irritation

Question 8

problems with neoplasms which are tubes/ducts/surfaces

Answer 8

perforation, occlusion, ulceration

Question 9

problems with neoplasms which are space -occupying

Answer 9

spinal cord compression

Question 10

problems with neoplasms - organ destruction?

Answer 10

liver failure from carcinomatosis, CNS invasion

Question 11

problems with neoplasms - organ encasement?

Answer 11

respiratory failure (pleural mesothelioma)

Question 12

cachexia?

Answer 12

muscle goes into catabolic mode, ‘cannibalises itself’, not reversable with nutritional support

Question 13

paraneoplastic meaning?

Answer 13

usually secretion of factors from neoplasms that the tissue wouldn’t usually secrete

Question 14

paraneoplastic complications

Answer 14

venous thrombosis
hypercalcaemia
neuropathies
dermatomycosis
finger clubbing
nephrotic syndrome

Question 15

field cancerisation?

Answer 15

expanded collections of cells that express some positively selected phenotypic changes needed for malignancy

Question 16

clonal mosaicism?

Answer 16

cells with genes with a survival advantage in a tissue expands a the expense of others resulting in a less diverse cell population in a tissue.

Question 17

what does mutation count and clone size increase with

Answer 17

chronic inflammation
carcinogens (sun exposure, smoking, alcohol)

Question 18

how does chronic inflammation cause an increase in mutation count and clone size

Answer 18

more regeneration, more DNA damage

Question 19

how do carcinogens cause an increase in mutation count and clone size

Answer 19

many chemical carcinogens do not mutate, but enable clonal expansion

Question 20

how many altered driver genes is needed to convert a normal cell to an early invasive cancer cell

Answer 20

around 3 - varies with cancer type and individuals

Question 21

what many cancerous tissues look like?

Answer 21

normal
hyperplastic (too many cells)
metaplastic
dysplastic (cells look weird - highest risk)

Question 22

clonal haematopoiesis?

Answer 22

driver gene mutations in bone marrow favour growth of bone marrow cells. cases white blood cells produced to be more inflammatory

Question 23

clonal haematopoiesis is a risk factor for which diseases

Answer 23

coronary heart disease, stroke, chronic liver disease

Question 24

where are vessels present in a cancer? what does this cause?

Answer 24

only on the outer parts, at some point as you get deeper the tissue pressure is too high. This causes tissue fluid to seep to the surface towards lymphatics (allowing any detached cancer cells to easily spread)

Question 25

acidity of a cancer tumor

Answer 25

pretty acidic as there is not much glucose or oxygen

Question 26

why is the outwards movement of tissue fluid in a cancer problematic for treatment

Answer 26

drugs aren’t likely to diffuse in, will only effect the surface of the cancer

Question 27

characteristic of fast growing cancer

Answer 27

viable cells around blood vessels and necrosis in-between

Question 28

what does chaotic angiogenesis create

Answer 28

chaotic blood flow (so silly so goofy)
pooling, eddies, flow reversals, leakiness etc. creates regional differences within a cancer

Question 29

what happens when cancer driver genes are multiply copied? what does this mean?

Answer 29

copies tend to detach from the chromosome and form a ring (similar to a bacterial chromosome)
this causes it not to be picked up in whole gene sequencing

Question 30

universal cancer tasks

Answer 30

division, accumulation of biomass, lipogenesis, immune interaction, invasion and tissue remodelling

Question 31

cancer trade off between conflicting tasks causes what?

Answer 31

cancers have to have plasticity to alter trade-offs between tasks

Question 32

mesenchymal plasticity?

Answer 32

carcinoma can reversibly take on characteristics of fibroblasts

Question 33

what does epithelial mesenchymal plasticity (EMP) allow cancer cells to do

Answer 33

move and therefore invade
downregulate proliferation therefore resist therapy that targets proliferating cells

Question 34

how do metabolic conditions in cancer impair the immune system

Answer 34

antigen signalling under metabolic stress causes CD8 T cell exhaustion. cancer cells very good at stealing all the glucose.

Question 35

what eliminates most circulating cancer cells

Answer 35

NK cells

Question 36

how do cancer cells subvert immune activation

Answer 36

release immunosuppressive factors. repress antigen processing and presentation. reduce MHC 1
display immune inhibitors

Question 37

how do cancer cells survive treatment

Answer 37

cancer treatments leave residual cells - reservoir for relapse
active resistant of treatment
genetic resistance - new clone develops