neoplasia Flashcards
what is the basic problem of neoplasia?
abnormal cell growth and differentiation
-uncontrolled and irregular
what is the result of the process of neoplasia?
neoplasm= tumor
what is a neoplasm (tumor)?
abnormal mass of cells
two types of neoplasms?
malignant (cancerous)
benign (non-cancerous)
what are malignant tumors? (cell growth rate, what is happening?)
- proliferation of cells is rapid, disorderly growth
- genes that regulate cell division become mutated
- cells undifferentiated need space so the cells secrete enzymes that damage the local tissue to create space
- it is damaging and invasive, irreversible and continous
- gains access to blood and lymph channels to metastasize to other areas of the body
what are benign tumors?
- rapid compared to normal proliferation of cells, but less rapid than malignant
- it needs space but it is encapsulated so it is less invasive
- many of these tumors will stop growing after a period of time
- undifferentiated and differentiated cells
- NO metastasis
differences between malignant and benign tumours
- malignant= INVASIVE, continuous, very rapid, metastasis, undifferentiated, damaging
- benign= non invasive, can stop, not as fast, no metastasis, encapsulated
what is apoptosis
programmed death/destruction of cells
all cancers known to humans, 50% of them have mutated gene..?
TP53
what are DNA repair genes
- repair defective DNA, fixing the problem instead of scrapping it
- if u wanted to cause cancer in the body you would likely target these genes
what are proto-oncogenes? (hint go)
commence cell proliferation, promote cell growth
GO!
what are tumor suppresor genes?
do not remove or suppress genes hehe
inhibit cell growth!
what are oncogenes?
genes that cause cancer! absolutely any mutated gene that is causing cancer
-can be put into any of the groups above
suffix “oma” is for?
BENIGN tumors!
suffix “sarcoma” is for?
MALIGNANT tumors if NON-EPITHELIAL ORIGIN
cartilage, bone, muscle
suffix “carcinoma” is for?
MALIGNANT tumors of EPITHELIAL origin
tumors double in size every?
approximately every 120 DAYS
so doubles approx 3/year
how long does it take for a tumor to be clinically detectable?
10 years
what size is a tumor detectable at by physical exam?
1 cm
how many cells are in a tumor of 1cm diameter?
1 billion cells
what size tumor will generally kill a person?
10 cm
methods of tumor spreading?
LOCAL
SEEDING
METASTASIS
what is local spreading?
-invades ONLY surrounding tissue
what is seeding?
-distant SPREAD, tends to happens within body cavities
what is metastasis?
-distant SPREAD “TRUE spreading” through blood and lymph
primary site (metastasis)?
-where tumor was first formed, origin of cancer
secondary site (metastasis)?
- where cancer cells spread to and proliferate
- most common is LYMPH tissue
sentinel lymph node?
=first lymph node affected by cancerous cells
with metastasis, it is usually widespread and…
leads to DEATH
does the tissue on the secondary site become malignant?
NO, tissue on secondary site is INVADED by malignant cells, gives them an area to GROW and DIVIDE
where does cancer usually metastasize to?
-LIVER, LUNGS, BONES, BRAIN
stage 1 of metastasis?
- cells begin to PROLIFERATE in LOCAL tissue
- secrete ENZYMES (break up cementing material between normal cells to make room for MORE proliferation)
- GROUPS of malignant cells ENTER blood or lymph (called EMBOLI)
- defense cells ATTACK but 1/10000 live
- platelets PROTECT and cover cancer cells!!!!
stage 2 metastasis?
- cancer SPREADS via BLOOD or LYMPH
- ARRIVE at SECONDARY site
- once SUITABLE site established: cancer cells use CYTOKINES and GROWTH factors to INVADE tissue
- cells at secondary site provide space for INVADING MALIGNANT cells
qualities of a suitable secondary site?
- resources for growth and division
- protection from defences
- room to grow
- -> cytokines help determine a suitable spot
ideally: LARGE and RICHLY VASCULARIZED
stage 3 metastasis?
-ANGIOGENESIS—> CA cells need BLOOD supply and RESOURCES to ensure SURVIVAL and cell growth
… so they create their OWN blood vessels
staging a tumor?
obtained clinically (physical, CXR, MRI etc) -global TNM (Tumor size, lymphNodes, Metastasis)
T0-4?
size of tumor and how much tissue has been invaded
- tX= cannot be assessed
- t0= no evidence of primary tumor
- t1-4= corresponds to size and how far it has spread
N0-3?
regional lymph nodes (NOT number of nodes, DEGREE of involvement)
- Nx= cannot be assessed
- N0= no evidence
- N1-4= corresponds to degree of spread to nodes
M0-1?
METASTASIS- it HAS or HAS not metastasized
what is grading?
obtained histologically (stain, under a microscope) -more subjective, higher= more anaplasia I to IV I= RESTRICTED growth IV= EXTENSIVE
treatment for cancer is done to achieve one of three things?
- eradicate the cancer
- control the malignancy or growth
- palliative: make the patient comfortable and functional
problems with treatment for cancer?
targets normal cells along with cancer cells, so normal cells that are rapidly proliferating are killed as well.
what is radiation therapy?
aim for control/cure (KILL malignant cells)
- achieves NECROSIS by bombarding CHEMICALS in malignant cells w/ radiation and form FREE RADICALS= cause cell DEATH (they interfere w/ dna, proteins, membranes)
- breaks DNA bonds and genetic molecules—> cell death
what is chemotherapy?
PHARMACOLOGICAL
-injecting DRUGS (IV, IM, or PO)
-drugs target RAPIDLY growing cells in body
-inhibit division of cancer cells by:
targeting ENZYMES to disrupt cellular processes
inhibiting DNA, RNA and protein synthesis
surgery for cancer?
removing the tumor
-often followed by chemo or radiation; remove AS MUCH as possible of tumor, THEN use other therapy to TARGET remaining cancer cells= COMBO
what is immunotherapy?
inducing, enhancing or suppressing an immune response
- use cytokines, antibodies, antigens (example= administer potent dose of TB antigens, trigger strong IR, immune cells target cancer)
- culture immune cells in lab and inject into body “in vivo= into patient”
what is hormone therapy?
CUTS off hormones that are feeding “hormone dependent tumours”
example: administer testosterone if tumor dependent on estrogen
- treat with drugs that are hormones or hormone antagonists
- DISRUPTS regulatory function
what is combination therapy?
COMBINE 2 or more of above (OFTEN 3)
-common= radiation + immunotherapy; surgery + chemo + radiation
why are there/ what are the side effects of chemo?
other rapidly growing cells are targeted (in bone marrow, digestive system, hair follices)
- causing impaired immune function, hair loss, nausea
