tumour pathology Flashcards
describe classification and nomenclature
classified according to tissue in which they develop
list differences between benign and malignant
benign do not metastasis not cancerous distinct, smooth regular borders can become large but will not invade or spread
malignant -
metastasis - grows faster
cancerous
irregular borders
define properties of cancer cells
grow and divide at abnormally rapid rate poorly differentiated abnormal membranes cytoskeletal proteins morphology metastasis sustained angiogenesis evasion of apoptosis
define spread of cancer and its mechanisms
circulatory system
lymphatic system
through body wall into abdominal and chest
list local effects of cancer
pressure obstruction tissue destruction (by ulceration/infection) bleeding (haemorrhaging/anaemia) pain (pressure on nearby nerves)
list systemic effects of cancer
normal or abnormal secretions of hormones, cachexia (weight loss), paraneoplastic syndromes, effects of treatment
identify concepts of dysplasia
presence of abnormal cells within tissue/organ
identify concepts of intra-epithelial neoplasia
abnormal cells found on surface of organ/tissue
process of cell division
mitosis and meiosis
mitosis = fundamental process for life
phases of cell cycle
G1
S
G2
M
checkpoints in cell cycle
surveillance that monitor order integrity and fidelity of major events of cell cycle
include
growth to appropriate cell size
replication and integrity of chromosomes
accurate segregation at mitosis
G1/S checkpoint
intra-S
G2/M
understand key molecules in cell cycle
cyclins and cyclin-dependent kinases (Cdks)
responsible for promoting cell cycle
describe how aetiological agents cause abnormalities in regulators of cell cycle
cells can divide without order and accumulate genetic errors
identify that tumour formation is a multi-step process
carcinogenesis = multistep
new, parasitic and polymorphic cancer cells evolve from a single, normal diploid cell
explain importance of genetic changes in cancer
certain gene changes can cause cells to evade normal growth controls and become cancer
some cancer causing gene changes increase production of a protein that makes cells grow
retinoblastoma protein
tumour suppressor gene that blocks cell cycle progression from G1 - S phase by inhibiting E2F transcription factors when unphosphorylated
on phosphorylation by cyclin-dependent kinases, RB1 is targeted for degradation and the E2F transcription factors are allowed to be active
tumour suppressor genes
normal genes that slow down cell division, repair DNA mistakes or tell cells when to die (apoptosis)
examples of tumour suppressor genes
retinoblastoma gene - RB1
BRCA1/BRCA2 - breast cancer genes - mutation in one of these increased risk of developing breast cancer
oncogenes
mutated gene that contributes to development of cancer
what are oncogenes called in their normal, unmutated state
proto-oncogenes and they play roles in regulation of cell division
examples of oncogenes
EGFR receptor of epidermal growth factor (EGF) involved in growth factor-mediated signalling
KDR receptor of vascular endothelial growth factor (VEGF) involved in angiogenesis
