Lecture 14: Cancer 2 Flashcards
cancer arises from ___ tissue
normal
plasias
growth & development
Hyperplasia:
Tissue growth containing excessive numbers of cells
Metaplasia:
tissue growth where cells appear abnormal
neoplasia:
invasive, abnormal tissue growth
Dysplasia:
tissue growth containing displaced but otherwise normal cells
benign tumours are:
confined, well defined structures
Malignant tumours are:
Early: dysplasia, anaplastic
Late: invasion metastasis
metastasis
the development of secondary malignant growths at a distance from a primary site of cancer.
benign tumour is one that:
grows locally, usually well differentiated + surrounded by a basement membrane/capsule and does not spread to other sites
Malignant tumour is on that
breaks through it basement membrane and spreads (metastasises) to distant parts of the body -usually poorly differentiated
Grading of malignant neoplasms: 1-4
1 = well differentiated 2 = moderately differentiated 3 = poorly differentiated 4 = nearly anapaestic
Adenocarcinoma
is a cancer originating in glandular tissue
To effectively treat cancers..
…we would like to identify them at an early stage
two hit hypothesis for tumour suppressor genes - who & dates?
knudson 1971
two hit hypothesis for tumour suppressor genes :
-First proposed for retinoblastoma
- Person at risk of familial cancer
- -inherit the first “hit” in the germ cell
- -The 2nd ‘hit’ in somatic cells during mitotic recombination
-In person with sporadically occurring cancer
both “hits” occur in somatic cells
Normal, heathy individual: Occasional cell inactivates one of its two good Rb genes
no tumour
hereditary retinoblastoma:
- inherited mutant Rb gene
- occasional cell inactivates its only good Rb gene copy
- excessive cell proliferation leading to retinoblastoma
most people with inherited mutation develop multiple tumours in both eyes
Non hereditary retinoblastoma:
- occasional cell inactivates one of its two good Rb genes
- the second copy of Rb is very rarely inactivated in the same line of cells
- excessive cell proliferation leading to retinoblastoma
only about 1 in 30,000 normal people develop one tumour in on eye
cytogenetic analysis facilitated the identification of
retinoblastoma gene
