3.1. introduction to cancer I Flashcards
Benign:
•Slow growth rate
•Histo resembles parent tissue
•Does not invade tissues (but may compress them)
- benign do have harmful effects due to size, chemical hormones etc. BUT they do not invade
Malignant:
- May grow rapidly
- Histo –may look very different to tissue of origin
- Invasive and may spread to other organs
When a neoplasm is benign the suffix ___
oma is added to the cell or organ of origin e.g. lipoma (adipose tissue)
When a neoplasm is malignant the suffix___
carcinoma or sarcoma is usually added to the cell or organ of origin e.g. pancreatic carcinoma, leiomyosarcoma).
lymphoma meaning
malignancy of lymphoid tissue
leukaemia meaning
malignancy of bone marrow
melanoma meaning
malignancy of melanocytes
Sarcoma meaning
Malignant neoplasm of mesenchyme (connective tissue), rarer than carcinomas, e.g. liposarcoma, osteosarcoma)
Carcinoma meaning
A malignant epithelial neoplasm
term for Malignant squamous epithelium:
carcinoma e.g. squamous cell carcinoma
term for Malignant glandular epithelium:
denocarcinoma e.g. colonic adenocarcinoma
term for malignant haematolymphoid
lymphoma/leukaemias
term Malignant pigmented skin (melanocytes)
melanoma
list the direct effects of cancer
- Pressure
- Obstruction
- Destruction of tissue
- Ulceration with bleeding and infection
list the indirect effects of cancer
- Cachexia(wasting) and fever
* Paraneoplastic syndromes
what usually causes death of a cancer patient?
It is usually not the original tumour which leads to death, rather it is the spread of the cancer to important organs like the brain, lung and liver which kills the person.
list the benign tumour shapes in epithelial tissues
- sessile
- polyp
- papillary
list the malignant tumour shapes in epithelial tissue
- fungating
- ulcerating
- annular
“differentiation” meaning with reference to cancer
How similar is the histological appearance of the tumour to the normal histology of that tissue
features indicating poor differentiation
- disorganisation
- change in appearnace of individual cells
- mitotic figures increases (i.e. many cells undergoing proliferation)
list the histological characteristics of cancer cells
- large number of dividing cells
- large, variably shaped nuclei
- large nucleus to cytoplasm ratio
- variation in size and shape
- loss of normal cell features
- disorganized arrangement
- poorly defined tumor boundary
what are the two pathways of cancer growth and progression
- carcinoma progression (carcinoma arising in an epithelium)
- the adinoma-carcinoma pathway
describe the carcinoma progression
- cell with genetic mutation
- hyperplasia (results in increased cell number)
- dysplasia (cells look different from surrounding)
- in situ cancer (basement membrane still intact)
- invasive cancer (invasion & metastisis occurs–> lots of epigenetic changes occur)
describe the adenoma-carcinoma pathway
- normal mucosa
- aberrant crypt focus (hyperproliferative epithelium)
- early adenoma
- late adenoma
- invasive cancer
What is the clinical significance of these pathways of cancer development?
Screening for early, treatable cancers
what are checks for early detection of cancer?
- pap smear
- mammogram
- colonoscopy
what form the basis of cancer?
- DNA mutations
•Spontaneous –cell division and DNA replication
•Induced –“mutagens” –e.g. toxins, irradiation - Epigenetic changes miRNA etc
*Cancer: The“right” combination of mutations and epigenetic changes in a single cell
why does cancer take time to develop?
- requires accumulation of mutations –> increasing predisposition to accumulate more genetic abnormalities
- accumulation of mutations takes time
- cancer increases in incidence with age
