AETIOLOGY OF CANCER 1 Flashcards
what is cancer?
a generic term for a large group of diseases that can affect any part of the body
what is one defining feature of cancer?
the rapid creation of abnormal cells that grow beyond their usual boundaries,
what is metastasis?
cells invade adjoining parts of the body and spread to other organs
what is the major cause of death from cancer?
Metastases
what is oncology?
study of tumours
what are tumours?
may be cancerous (malignant) and often fatal or they may be harmless
what are malignant neoplasms?
carcinoma in situ and cancer
what are malignant tumours capable of undergoing?
metastasis - break through the basement membrane and migrate to additional sites
what are benign tumours?
don’t metastasize - remain encapsulated by connective tissue fibrous sheath
what are the 5 main groups of cancer?
Carcinoma (epithelial) Lymphoma (lymphatic system) Leukaemia (blood cells) Sarcomas (connective tissue) CNS tumours (brain & spinal chord)
what are the characteristics of benign tumours?
Microscopic appearance considered innocent implying the tumour will remain localised
Tumour remains encapsulated in CT (fibrous) sheath (basement memb)
how are benign tumours treated?
Amenable to surgical removal
or patient survives in they’re encapsulated
what are malignant tumours?
Malignant neoplasms can invade and destroy adjacent structures
Tumour cells breach encapsulated CT (fibrous) sheath (basement memb)
what happens if malignant tumours metastasise?
Can lead to patient death
how can benign epithelial tumours vary?
according to appearance
what are the different classes of benign epithelial neoplasms?
Glands – adenoma
Surfaces – papilloma
Mucous surfaces – polyp
Hollow masses - cysadenoma
what are cells derived from mesenchyme called?
sarcoma
what are cells derived from epithelia called?
carcinoma
what are the exceptions in malignant tumour terminology?
melanoma, lymphoma are malignant
why are tumours bad for us?
Local tissue destruction
Obstruction/compression
Hormonal malregulation
what is tumour prognosis based on?
Based on a diagnostic assessment of
grade
stage
what is grade?
how closely the tumour histology resembles the tissue of origin
what is stage?
how far the tumour cells have spread from the nidus (place where something is formed/deposited)
what does TMN stand for?
Tumour, size Node, local number involved Metastasis occurrence
what are the tumour-specific classification systems?
Bloom and Richardson- breast carcinoma
Dukes’ - colorectal carcinoma
Ann Arbour - lymphoma
Breslow/Clarke’s- melanoma
Why do we need new anticancer treatments?
majority don’t respond well – treatment is palliative (symptom relief) rather than curative
what is a neoplasm?
A mass formed by the autonomous proliferation of cells that persists after cessation of the stimulus that provoked the change
or “new growth”
what causes neoplasm or tumour?
Abnormal proliferation of cells
are all neoplasms malignant?
no
how do normal cells transform to neoplastic cells?
via a series of changes
what does cell transformation result in?
results in a cell population capable of proliferating independently of both internal and external signals that normally regulate their growth
what are the 2 controls on cell division?
external
internal
what does external cell division include?
population density
cytokines (growth factors)
substratum signals
what does internal cell division include?
activity of proliferation genes
activity of anti-proliferation genes
what is cell division dependent on?
on signals and sensors