Cancer Flashcards
What is neoplasm and how is it classified
The autonomous growth of tissue which have escaped normal constraints on cell proliferation.
Growth continues after stimulus is removed
Classification:
Primary description based on cell origin
Secondary description based on whether it is benign or malignant
Define Tumour
Any kind of mass forming lesion ( a region in an organ or tissue which has suffered from damage through injury or disease)
Define Cancer
Are Malignant neoplasms
Define hamartoma
Localised benign overgrowth’s of one of more mature cell types.
they represent architectural but not cytological abnormalities.
Define heterotopia
Normal tissue being found in parts of the body where they are not normally present.
What are the 4 factors that differentiate malignant against benign?
- differentiation and anaplasia
- rate of growth
- local invasion
- metastasis
1.Differentiation refers to the extent to which the parenchymal cells resemble there normal counterparts.
Malignant: abnormal mitoses, tumour cells tend to have larger nuclei ( and hence a higher nuclear- cytoplasmic ratio
Benign_ relatively well differentiated
Malignant show anaplasia (the loss of the mature or specialized features of a cell or tissue, as in malignant tumours.)
2.Benign tumours grow slowly
Malignant tumours grow more rapidly.
3.Most benign tumours grow as cohesive expansile masses that remain localised to their site of origin
Benign: don’t tend to infiltrate the basal lamina
Malignant: infiltrate the basal lamina
Metastasis: spread via blood vessels to other parts of the body- benign don’t
4. Benign tumours don’t metastasise
List five routes by which tumours spread
- Direct extension:
- Heamatogenous
- Lymphatic
- Transcoelomic
- Perineural
Explain the five routes by which tumours spread
-Direct extension: Associated with a stromal response to the tumour.
Includes, fibroblastic proliferation, vascular (angiogenesis) and an immune response
-Heamatogenous: via blood vessels, usually venules and capillaries because they have thinner walls
-Lymphatic: via lymphatics to lymph nodes and beyond
-Transcoelomic: seeding of body cavities (e.g. pleural, peritoneal)
-Perineural: via nerves
List 3 ways tumours are staged
Clinically
Radiologically
Pathologically
Describe the basis of the TNM staging system
T: tumour, the size or extent of local invasion/Primary Tumour size
N: nodes, number of lymph nodes involved
M: metastases, present of distant metastases
Explain the importance of grade and stage in determining the prognosis of cancers
Grade= how differentiated is the tumour and on the numbers of mitoses
Stage= how far has the tumour spread (uses TNM system)
STAGE is more important than Grade for prognosis.
How to tell the difference between benign and malignant by name?
Benign suffix “oma”
Malignant suffix “ sarcoma”
Except sarcoma and carcinoma which are malignant
What do we call the cancer cells?
Parenchyma
What is stroma?
Tissue around the cancer cells that consists of connective tissue, blood vessels, macrophages, lymphocytes- its a supportive system for the cancer cells
3 ways of inheriting cancer
- Autosomal dominant cancer = familial adenomatous polyposis
- Defective DNA repair = Xeroderma pigmentosum
- Familial cancer syndrome = unknown cause but runs in family e.g breast cancer
Non hereditary cancers causes
Risk factor e.g. liver cirrhosis and HCC Inflammation and cytokines can cause cancer
What is carcinogenesis?
Acquiring malignancy in over a period of time due to multiple mutation
Carcinogens
Agents that cause genetic damage and induce neoplastic transformation of cells
3 categories:
Chemicals
Radiation
Microbial agents (mainly viruses) e.g. HPV cervical cancer
4 regulatory genes and examples of cancers caused by loss of regulation in each
Oncogene = burkitts lymphoma mYC
Tumour suppressor genes = BRCA 1/2
DNA repair genes = genomic instability syndrome
Apoptosis = bcl-2 (usually regulates apoptosis) upregulated in lymphomas
Diagnosis and testing
Biopsy
Fine needle aspiration Scans PCR / FISH
What is Parenchyma?
Parenchyma: the cancer cells that have been transformed
Define dysplasia
disordered growth, limited to epithelium.
What is metaplasia
Substitution of one mature cell type for another mature cell type more suited to the environment
e.g. Smoking causes metaplasia of glandular bronchial epithelium to squamous epithelium
what are the 2 exceptions that do not metastasise?
- Gliomas
- Basal cell carcinomas
These 2 do not metastasise
