NEOPLASIA & ENDOCRINE Flashcards
what are the most prevalent cancers in females?
1.breast- 2. lung- 3. colon
what are the most prevalent cancers in males?
- prostate- 2. lung- 3. colon
what is the use of imaging in cancer?
screening, detection (either investigating or incidental- person may have clinical signs), monitoring (imaging shows if the selected therapy is effective)
what is detection based on?
identified abnormalities of soft tissue or bone, functional imaging, molecular imaging
what is diagnosis ultimately based on?
biopsy/pathological examination
what is neoplasia?
a spectrum of diseases based on biopsy/pathological examination- cause defect in control of cell growth leading to excessive, unregulated growth leading to tissue mass- new, uncontrolled growth of cells that are not under physiological control- create neoplasm
what is neoplasm?
an abnormal mass of tissue that results when cells divide more than they should or do not die when they should (apoptosis)
what is normal cell growth controlled by?
by humoral (endocrine) factors & direct cell to cell interactions
what is a tumour and a cancer?
tumour is a lump which may not be neoplastic- cancer implies malignancy
what can cells undergo?
can undergo atrophy (smaller), hyperplasia (increase in cells- too much can lead to dysplasia), metaplasia (cells change- may lead to dysplasia)- hypertrophy (cells increase in size- can lead to hyperplasia)
what do cancers result in?
proliferation, invasion & metastasis- can be mutations (change in genetic code) or epigenetic changes (influence gene expression & cell behaviour, transmitted to daughter cells but not changes in genetic code)- may occur in cancer stem cells
what are cargionogens?
radiation, chemicals, oncogenic viruses, chronic inflammation, physical substances
how is radiation carcinogenic?
dependent on dose & additive- radiation damaged cells are more susceptible to other carcinogens- radiation damages DNA and also affect gene involved in DNA repair
how are chemicals carcinogenic?
2 steps: initiation (carcinogen leads to DNA damage but not neoplastic change)- promotion (2nd carcinogen leads to damage to iniated cells & neoplastic changes)- doesnt cause neoplastic change in uninitiated cells
what are examples of carinogens?
oncogenic virus (virus that has potential to cause cancer, by damaging the DNA by inserting their viral DNA to the host DNA)- chronic inflammation- physical substances
what has to occur to have a neoplastic transformation?
believed to almost always be multifactorial, with a series of cellular events adding to each other
where do cancers come from?
90% of cancers are environmental (non-heritable), 10% are genetic (inherited from your parents)
how does carcinogenisis occur?
environmental agents damage DNA & inhertied mutations- cells can either repair or be damaged, which cause mutations & can either undergo oncogenesis, impaired apoptosis (cells that should die dont, inactivation of tumor suppressor genes- alters gene production causing malignant tumour
what are the causes of breast cancer?
more than 90% of women with BRCA mutation develop breast cancer BUT 90-95% of breast cancer in women do not have the mutation- cancer is due to spontaneous after birth- only way a mutation can be passed on is if cancer is in a oocyte or sperm cell
where must the mutation occur to pass to the next generation?
must occur in germ cell e.g. sperm or oocyte
what are characteristics of cancer cells?
proliferate despite lack of growth initiating signals, avoid apoptosis due to presence of telomerase (excessive shortening which prevents it to repair), lose differentiated features & don’t contribute to organ function, ability to metastasise (malignant= spreads to different sites in the body)
is the tumour cell population heterogenous?
yes- overtime, many cancers become more adapted to the environment & difficult to treat
how do tumour cells change?
changes to metabolic pathway to help tumours cope to hypoxic environment & increase angiogenesis
what are hypoxic cells?
cells are deprived of oxygen- has an adverse effect on radiotherapy- cause selection of cells with apoptotic insensitvity & increased angiogenic potential- adaptation that helps them to survive
how are cancer classified?
by their tissue of origin or anatomic location
what are the 3 cell lineages established during development?
ectoderm (rise to external surface), endoderm (internal body surface), mesoderm (rise to tissue in between)
where do malignant carcinomas & sarcomas arise from?
carcinomas (ectoderm or endoderm e.g. lung, colon, breast)- sarcomas (mesoderm e.g. bone, muscle, cartilage, blood)- most common form of cancer & travel via lymphatic system- tumours that arisen from the ectoderm
what population are sarcomas & carcinomas popular in?
carcinomas (adults)- sarcomas (active in growing infants & children because mesenchymal tissue are active)
what are carcinomas derived form?
epithelial cells (squamous cell carcinoma) & glandular epithelium (breast, prostate, lung, stomach)- most common form of cancer
what are sarcomas derived from?
haemotopoietic tissue (leukaemia & lympoma), connective tissue (cartilage, fat, muscle, bone)- usually spread by blood- more common in growing infants & children because mesenchymal tissues are very active
what are examples of benign tumours?
have suffix “oma” e.g. adipose tissue (lipoma), skin (papilloma)
what are preinvasive (or carnicoma in situ) carcinoma?
not invaded any surrounding tissue
what are invasive carcinomas?
invaded surrounding tissue
what are metastatic tumours?
spread to distant organs & other tissue via lymphatics or blood stream
what may indicate a preclinical phase?
e.g. polyps in colon- may precede the development of cancer by years or may not progress to cancer