Cancer Flashcards
what is cancer and who does it affect?
uncontrolled and unregulated growth of cells
occurs in all ages and ethnicities
what is the leading cause of death in Canada 1st and second?
1st - cancer
2nd - cardiovascular disease
what defects in cellular proliferation cause cancer?
normally a state of equilibrium is established. cell proliferation (division) equals cellular degeneration
normal cells respect their boundaries and territory of the cells surrounding them but cancer however cells have loss of contact inhibition and break cellular boundaries (grow on top of one another or between other cells)
what are defects in cellular differentiation that cause cancer?
the cell progresses from a state of immaturity to a state of maturity
usually differentiation is stable and orderly
1) benign neoplasms - well differentiated
2) malignant neoplasms - undifferentiated (have the ability to invade and metastasize
know benign vs malignant cell characteristics (YouTube)
what causes cancer?
each type of cancer is likely multifactorial
what are the 3 stages of cancer?
1) initiation - mutation in cells genetic structure from an inherited mutation, an error that occurs during DNA replication or after exposure to a carcinogen
2) promotion - reversible proliferation of the altered cells
3) progression - increased growth rate of the tumour and increased invasiveness and spread of the cancer to a distant site (metastasis)
what carcinogen can initiate and promote development of cancer?
tobacco
when is cancer “clinically evident”?
when 1 cm tumour is present (contains 1 billion cancer cells)
what does the body do to protect itself from ingested carcinogens?
carcinogens are detoxified by protective enzymes and harmlessly excreted but if protective mechanism fails, carcinogens can enter the cells nucleus and alter its DNA
what are the frequent sites of metastasis?
lungs, brain, bone, liver and adrenal glands
explain the process of metastasis
it is a multistep process
rapid growth of the primary tumour then it continues to increase its size and develops its own blood supply. then it grows and invades surrounding tissues. sometimes some tumour cells can detach from primary tumour and invade surrounding tissue like lymphatic or vascular vessels
can the immune system recognize cancer cells?
cancer cells can present themselves to be normal so the immune response may be inadequate to reject and destroy the cancer cell
what are the 7 warning signs of cancer? acromegaly: CAUTION
Change in bowel movements or bladder
A sore that doesn’t heal
Unusual bleeding or discharge
Thickening or lump
Indigestion
Obvious mole or wart
Nagging cough or hoarseness
what are goals of chemotherapy?
cure, control and palliation
how does chemo work?
radiation breaks bonds in DNA this causes chromosomal disruption so they cant replicate
