Neoplasia Flashcards
(26 cards)
what is cancer?
uncontrolled cell division
invading other tissues
what is neoplasia?
new growth not in response to a stimulus
what three classifications could a neoplasm come under?
benign
premalignant
malignant
what does malignant mean?
the growth has metastatic potential
what are metastases?
cancer cells that have spread to sites distal to the primary tumour
name three precursor stages to malignancy
dysplasia
metaplasia
hyperplasia
what is dysplasia?
disordered growth, not in response to a stimulus
what is invasion?
growth beyond the basement membrane
is there invasion is dysplasia?
no
what does a high grade/low grade mean in dysplasia?
lower the grade the closer to normal
higher the grade the closer to becoming cancerous
what causes metaplasia?
increased stress
what is metaplasia?
the reversible change from one mature cell type to another mature cell type
what is carcinoma in situ (CIS)?
dysplasia affecting the whole of the epithelium
what is the last stage before dysplasia becomes invasive and malignant?
carcinoma in situ
what does the double hit hypothesis state?
two faulty copies needed to have a functional problem
one copy = increased risk
what effect does UV radiation have on DNA?
causes the formation of pyrimidine dimers in the DNA, which eventually overwhelms nucleotide excision repair (NER)
what causes xeroderma pigmentosum?
a genetic defect in NER
what oncogenes are produced by HPV?
E6
E7
what does E6 do?
increases the destruction of p53
what does E7 do?
prevents retinoblastoma protein from acting
what is the usual role of Rb and what happens if this doesn’t occur?
usually binds to E2F
if not, E2f promotes transcription of DNA polymerase = increased rate of cell division
what cancers are Ras mutations associated with?
colon
lung
what cancer is Braf mutation associated with?
melanomas
what drug can be used to treat Braf associated melanomas?
vemurafenib
