cancer - quiz #3 Flashcards
(41 cards)
most basic level of cancer
abnormal cells that uncontrollably divide & never die
-accumulate together into clumps called “tumors” or flow freely through bone marrow, lymphatic fluid, body tissues & blood
how does cancer spread
throughout body via bloodstream, invading other tissues
-can be compared with a parasite that drains energy from body & competes for its nutrients
NEOPLASIA
“new growth” NOT controlled by normal regulatory mechanisms – cells do not contribute to organism, but draw on its resources
-masses form together into clumps called “neoplasms” or “tumors”
-may be malignant/ benign
Study of malignant cancer
ONCOLOGY
6 UNIQUE CHARACTERISTICS of cancer cells that are different than any other cell in body
- Anaplasia
- Anchorage independent
- Lack of contact inhibition
- Immortality
- Angiogenesis
- Genetic instability
ANAPLASIA
-cells undifferentiated → have not developed into particular cells yet
-NO function (other than reproducing)
-variety of shapes & sizes
-unusually large nuclei & bear little/ no resemblance to normal cells in surrounding tissues
ANCHORAGE INDEPENDENT
-cancer cells detach from bottom of culture flask, floating away in soft agar & form new colonies (unlike normal cells that are anchored)
-encourage cancer cells to invade nearby tissue & expand outwards to go elsewhere in body
LACK OF CONTACT INHIBITION
-when normal cells contact each other/ contact basement membrane, attempt to move apart to avoid damage/ collision
= “contact inhibition
-cancer cells do not possess this normal cell trait
IMMORTALITY
-reverse shortening of telomeres & lengthen telomeres every time they divide, making them immortal
-may continue to divide for years with right conditions
ANGIOGENESIS
-tumors need blood supply if they grow larger than few millimeters
-cancer cells have ability to secrete chemical stimulators that stimulate angiogenesis in nearby tissues
-develop vascular network to bring oxygen & nutrients for continued growth & expansion of cancerous cells & tumor
GENETIC INSTABILITY
-divide continuously & have tendency toward genetic alteration during cell division
-causes genetic damage
-cancer often caused by damage to genes that help control cancer in body like tumor suppressors
BIOCHEMISTRY (biology of tumor cell)
cancerous cell requires less oxygen – has no other function besides reproducing, accumulating & spreading – may acquire new functions (anaplasia) – very simple metabolism
GROWTH PROPERTIES (biology of tumor cell)
survives easily, requires less nutrients – all energy goes to growth & reproduction – some cancer cells are immortal, lack contact inhibition, have anchorage dependant growth, do not require external growth factors – some tumors produce their own = “autonomous”
cancerous cell growth has 3 distinct features that differentiate it from normal cell growth
AUTONOMOUS
EXCESSIVE
DISORGANIZED
AUTONOMOUS (cancer - cell growth)
dependant of normal growth factors & inhibitors
EXCESSIVE (cancer - cell growth)
does not respond to normal growth & division regulators
DISORGANIZED (cancer - cell growth)
tissues formed are irregular
clinical classification of tumors (determine malignant/ benign)
looks at clinical presentation & outcomes of cancer
histologic classification of tumors (determine malignant/ benign)
looks under microscope at cancerous tissues/ cells, determines what type of cells the cancer is made up of
non cancerous tumors & may arise from any tissue type
BENIGN
cancer defined by limited growth potential with good prognosis/ outcome – curable
MALIGNANT
cancer is defined by uncontrollable growth – will eventually kill host
-causing metastatic cancer
METASTASIS
process where tumor cells move from one site in body to another – only malignant cells can spread
3 main pathways for spread:
-Lymphatic system
-Bloodstream (hematogenous spread)
-Seeding of surfaces of body cavities (close by)
METASTATIC CASCADE
-as tumor grows, some cells develop ability to metastasize, some do not
-enter lymphatic system, bloodstream, close-by cavities – fluid carry tumor cells away to different site, they attach & form tumor
-cancerous cells must escape immune systems attack with T-lymphocytes, natural killer & macrophages
-must form new blood supply to bring oxygen & nutrients for new tumors to grow = angiogenesis
CLASSIFICATION OF TUMORS
Mesenchymal tumors
Epithelial tumors
Blood cell & lymphocyte tumors
Tumors of glial cells
Germ cell tumors
