Tumour Behaviour Flashcards
why do we get variations in cancer types and subtypes?
varaiation arises from:
- order mutations occur
-
which mutations occur
- get parralel pathways existing to create tumoregenic cells
is carcinogensis one or multi-step process?
(need to know about adenocarcinoma?)
multi-step process. requires several mutations
what are cancer stem cells?
what do their properties depend on?
definition: cells with self renewal potential in order to produce the variety cells that form tumours. (the stem like properties are similar to normal stem cells).
- can self renew OR extensivelly differentiate into a cell type that then propogates additional cancer types
- the proporties of the cancer stem cells depends on the epigenetic changes within genes and RNA transcript
what are the two hypothesis for the generation of cancer stems cells?
- cancer stem cell model
- clonal evo model
explain the cancer stem cell model
- normal progenitor cell -> can develop into differentiated normal breast cells
- within tumours / tissues that will become cancerous: abnormal progenitor cells exist. can self-renew.
3. abnormal progenitor cells acquire mutations and ability to proliferate become: mutated progenitor cell
- mutated progenitor cell self renew and become: cancer stem cell. can also dedifferentiate
5. further mutations: some will become tumour cells, others remain as stem cells
explain clonal evolutionary model
clonal evolutionary model
(overview: differentiated mammry cells gain mutations and undergo dedifferentiation process. (NOT PROGENITOR CELLS LIKE LAST H)
- start off as differentiated stem cell and mutation occurs
- after 1st mutation: no longer properly functioning mammary epi. cells. acquires characteristics of mutated stem cell
- after 2nd mutation: forms a cancer cell
- undergoes dedifferentiation: forms cancer stem cell
- cancer stem cell becomes cancer cell or cancer stem cell
what are the three critical determinants of tumour classification?
1. differentation state
- epithelial
- non epithelial
- mixed
2. embryonic origin
- ectoderm
- endoderm
- mesoderm
3. biological behaviour
- benign
- malignant
epithelial tumours are derived from which germ layers?
connective tissue tumours are derived from which germ layers?
bone tumours are derived from which germ layers?
nervous tumours are derived from which germ layers?
- epithelial tumours dervied from: ectoderm, endoderm and mesoderm
- connective tissue tumours dervied from: mesoderm
- bone tumours dervied from: mesoderm
- nervous tissue tumours dervied from: ectoderm
name a epithelial tissue that is derived from each germ layer
(probs just for awareness)
what are the two major categories of epithelia that inform what the type of carcinoma (epithelial cancer) will be?
covering and lining epithelia
- e.g. lining of skin / lining of interal organs / forms lining of fucts and body cavities
- stratified squamous
glandular epithelia
e. g. thyroid, adrenal and sweat glands. glands in breast and prostate
- simple cuboidal and simple columnar
what are the most common human cancers?
= epithelial in origin
- > 80% cancer related deaths in W. world
name the two specific types of carcinoma that are prevalent
- producing reconizable squamous cells: squamous cell carcinoma - (nasal cavity, larynx, lung, cervix and skin)
2. glandular growth pattern: adenocarcinoma (e.g. lung, colon, breast, pancreas, stomach, prostate)
BUT: IMPORTANT TO NOTE -> IN ONE TISSUE WILL HAVE BOTH TYPES OF EPITHELIAL CELLS: CANCER CAN DERIVE FROM DIFFERENT EPITHELIAL TYPES
how do you do nomenclature of a begign tumour?
- name of cell origin
+
- morphological character
+
- oma (means its benign)
* e.g squamous cell papilloma*
- oma (means its benign)
which tissues make mesenchymal / stromal derived tumours?
which tissues make all three germ layer tumours?
what are:
- adenomas
- papillomas
- cystadenomas?
- what are polyps?
all: BENIGN EPITHELIAL TUMOURS
adenoma: tumour forming glands
papilloma: tumour with finger-like projections
cystadenoma: cystic tumour
polyp: tumours that projects above mucosal surface