Intro to Neoplastic Disease Flashcards
Define neoplasm.
AN abnormal mass of tissue that forms when cells grow and divide more than they should or do not die as they should. The growth exceeds and is uncoordinated with that of normal tissues and which persists in the same excessive manner after the cessation of the stimuli that has evoked the change.
What are malignant tumours?
Neoplastic cells can divide and spread into local sites and can often spread via blood or lymphatic flow in haematogenous or lymphatic spread. Males them hard to treat and cure.
What are benign tumours?
Tumours do not invade surrounding tissues or spread to other sites. can have fibrous tissue capsule, grow by expansion and can compress surrounding tissues, which can be fatal if compression of brain spinal cord or major blood vessels.
Define metastasis.
When neoplastic cells break away from a tumour and spread to a distant site and from a new tumour. Malignant tumours metastasise.
What genes are involved in epigenetics of neoplastic disease?
Proto-oncogenes encode proteins that stimulate cell growth and division. When mutations occur in these genes, they becomes oncogenes/cancer causing genes.
Tumour suppressant genes encode TS proteins that inhibit cell cycle.
What is the Clonal Evolution/Stochastic Model?
Any cell may be the target of carcinogenesis and arises from random mutation events. Most are passenger mutations but will occasionally be a driver mutation that gives the cell a growth advantage to proliferate faster. Cell outcompetes the first clone for resources, which repeats to form a neoplastic mass. Invasive and metastatic abilities may develop.
What is the Cancer Stem Cell Model?
Daughter cells become progressively differentiated and limited proliferation. Can undergo symmetric or asymmetric cell division, the only way they can form sub-clonal populations. Invasive and metastatic abilities may develop.
If cancer stem cells and non-cancer daughters were separated, only cancer stem cells would produce new tumours.
What significance do the 2 models have on treatment?
It is unknown which model is correct, as some cancers fit better with different models. But it is important to think which types of cells must be targeted for treatments and cures.
