general pathology of cancer Flashcards
neoplasm=
new uncontrolled growth of cells that is not under physiological control
cancer=
malignant tumour/ neoplasm
is neoplasm always cancer
no neoplasm can be benign or malignant
4 classes of normal regulatory genes
- proto-oncogenes
- tumour suppressor genes
- genes controlling PCD
- genes that repair DNA
what do mutated proto-oncogenes produce
oncogenes
what is a proto-oncogene mutation usually (about function)
a gain in function
important example of proto-oncogene
Epidermal growth factor receptor
EGFR
what is EGFR
a tyrosine kinase (receptor)
2 general effects of EGFR mutations
cell proliferation
avoiding apoptosis
In what cancer are 8% EGFR mutations
lung cancer
what are tumour suppressor genes
any gene whose normal function acts to suppress cell growth and proliferation, causes apoptosis
most important tumour suppressor gene
p53
Li-fraumeni syndrome=
rare inherited loss of p53
what is p53 job
targets damaged cells for apoptosis
what is the risk of malignancy by 70yrs with Li-fraumeis syndrome
100%
carcinogens=
agents that cause genetic damage and induce neoplastic transformation
high risk HPV strains=
strains 16-18
low risk (anogenital warts) HPV strains =
6, 11
what does HPV do
infects cervical epithelial cells where it produces viral proteins E1-E7
what do viral proteins E6 and E7 do
interact with cell cycle proteins pRb and p53 reducing levels and promoting DNA synthesis
what cancer can helicobacter pylori cause
gastric carcinoma and low grade lymphoma
metaplasia=
the transformation of one completely differentiated cell type into another because of a stimulus
why does metaplasia happen
change in environment produces cells better equipped to withstand new environment
2 type of metaplasia
squamous
glandular
squamous metaplasia=
glandular epithelium becomes squamous
happens in chronically inflamed ducts
where does glandular metaplasia happen
in oesophagus squamous-lined to columnar lined with goblet cells (barretts oesophagus)
which type of metaplasia is more serious (risk of cancer)
glandular metaplasia
dysplasia=
(how it looks) the presence of cells of an abnormal type within a tissue, which may signify a stage preceding the development of cancer.
4 features of dysplasia
increased proliferation
loss of relationship between cells
lots of cell death and disorder
cell morphological transformation
if you remove the stimulus in what happens to dysplasia
may restore to normal cell growth pattern
what is neoplasm in origin
monoclonal (result of proliferation of a single transformed cell)
what makes something malignant
when the cells start to invade beyond the basement membrane or spread
malignancy=
invasion and spread
name of tumour of surface epithelia=
papilloma
name of solid and surface glandular epithelia
adenoma
malignant neoplasm of any epithelial origin
carcinoma
suffix for malignant tumours of connective tissue
-sarcoma
suffix for benign tumours of connective tissue
-oma
what does a teratoma contain
all three embryological germ layers
where are teratomas usually found
gonads (ovary/ testies)
ovarian teratomas=
benign
testicular teratomas=
malignant
main characteristic of benign tumours
no capacity to metastasize
5 facts about malignant tumours
- rapid growth
- ill defined boarders
- infiltrate margins
- invades surrounding tissue
- ability to metastasize
metastasis=
distant spread of neoplastic cells away from main (primary) neoplasm to form sub populations of cells not in continuity with primary
3 routes of metastasis
haematogenous
lymphatic
transcoelomic
main vessels metastasise flow in
veins (thinner walls)
transcoelomic=
spreads directly across coelomic spaces and surfaces
what is commonly transcoelomic spread
ovarian cancers
what grade would a well differentiated tumour have
low grade
what is the worst type of poor differentiation
anaplasia
anaplasia=
malignant neoplasm composed of undifferentiated cells
4 features of anaplasia
pleomorphism (variation in size and shape)
Abnormal nuclear morphology
mitoses
loss of polarity
tumour grade=
based on degree of differentiation
stage=
extent of tumour spread within the body
what can stage help inform
prognosis and treatment
TNM=
t= primary tumour N= lymph node status M= metastasis
cachexia=
wasting syndrome (usually in advanced cancer) catabollic state resulting in profound loss of body fat and mass, weakness and anorexia
what causes cachexia
action of molecules secreted by neoplasm and host response- TNF-alpha, IL-1, IFN-gamma
paraneoplastic syndrome=
symptom complexes that cannot be explained by local or distant spread of tumour
