Cancer Development (exam 1) Flashcards
What is an increase in tissue size (cell growth)?
hypertrophy
What is an increase in the number of tissue cells (cell growth)?
hyperplasia
What does “neo” mean?
new growth
What is a neoplasm?
tumor
Neoplasms can either be ___ or ___.
benign or malignant
Any new or continued growth not needed for normal development or replacement of dead or damaged tissues
tumor
Noncancerous tumor
benign
Cancerous tumor
malignant
Which tumor does not always require intervention?
benign
What is the biology of a normal cell under the microscope?
- specific morphology (specific to where it belongs, cardiac, skin, etc.)
- small nuclear to cytoplasmic ratio (smaller nuclear to a bigger cytoplasmic)
- differentiated function
- tight adherence because of proteins (sticking close together
- nonmigratory (stays in place, does not move around)
- orderly and well generated growth (mitosis- cyclic pattern that splits one cell into two, skin/GI/mucous cells regenerate more frequently)
- contact inhibition (does not goes pass boundaries)
- Apoptosis (dies on a schedule basis)
- Normal chromosomes (23 pairs in every cell)
What are the phases of the cell cycle in order?
G0, G1, S, G2, M
In this phase, cells actively carry out there function but do not divide, Where normal cells spend most of their live.
G0
In this phase, the cell is getting ready for division by taking on extra nutrients, making more energy and growing extra membrane. The amount of cytoplasm increases.
G1
In this phase, the cells double its DNA synthesis.
S
In this phase, the cell makes important proteins that will be used in actual cell division and in normal physiologic function after cell division is complete.
G2
In this phase, the single cells splits apart into two cells(actual mitosis).
M
What are the features of a benign tumor cell?
- continuous or inappropriate cell growth
- specific morphology
- small nuclear to cytoplasmic ratio
- specific differentiated functions
- tight adherence
- no migration
- orderly growth
- normal chromosomes
What is the differences in features of a normal vs benign cell?
benign cells have continuous or inappropriate cell growth
What are the features of malignant cancer cells?
- rapid or continuous cell division
- anaplasia (cells does not look like parent cells)
- Larger nuclear to cytoplasmic ratio
- specific function lost
- loose adherence
- migration
- rapid continuous
- abnormal chromosomes (aneuploidy) DNA is not normal
Carinogenesis/oncogenes =
cancer development
Malignant transformation occurs through these stages
initiation, promotion, progression and metastasis
The first step in carcinogenesis, excessive cell division.
imitation
The second step, that involves promoters (enhanced growth of an initiated cell by substances) and the latency period (the time between a cell’s initiation and the development of an overt tumor, which can range from month to years).
promotion
The third step, continued growth, after cancer cells have grown to the point that a detectable tumor is formed (a 1 cm tumor has at least 1 billion cells in it).
progression
The final step, when cancer cells move from the primary location by breaking off from the original group and establish remote colonies.
metastasis
Metastasis occurs through
- extension into surrounding tissues
- blood vessel penetration
- release of tumor cells
- invasion
- local seeding (can occur during surgery from left over tumor cells)
- bloodborne metastasis
- lymphatic spread
What are the 4 stages of metastasis?
- malignant transformation
- tumor vascularization
- blood vessel penetration
- arrest and invasion
Some normal cubodial cells have undergone malignant transformation and have divided enough times to form a tumorous area within the cubodial epithelium during this stage
malignant transformation
Cancer cells secrete vascular endothelial growth factor (VEGF), stimulating the blood vessels to bud and form new channels that grow into the tumor during this stage
tumor vascularization
Cancer cells have broken off from the main tumor. Enzymes on the surface of the tumor cells make holes in the blood vessels, allowing cancer cells to enter blood vessels and travel around the body during this stage
blood vessel penetration
Cancer cells clump up the blood vessel walls and invade new tissue areas. if the new tissue areas have the right conditions to support continued growth of cancer cells, new tumors (metastatic tumors) will form at this site during this stage
arrest and invasion
Cancer classification (7)
- tissue of origin
- grading
- ploidy
- staging
- TNM
- doubling time
- mitotic index
Tissue of origin
the type of tissue from which the cancer arise (liver, blood vessel, bone, nerve tissue, kidney, glial cells/brain. etc.)
Grading
classifies cellular aspect of the cancer (Gx, G1, G2, G3, G4).
Gx= can’t grade
G1= slightly different from parent cell
G4= a whole lot different
Ploidy
classifies tumor chromosomes as normal (euploidy) or abnormal (aneuploidy)
Staging
classifies clinical aspects of the cancer (clinical, surgical, pathologic/most definitive)
TNM
tumor, node, metastasis
Doubling time
the amount of time it takes for a tumor to double in size
Mitotic index
the percentage of actively dividing cells within a tumor
Staging of primary tumor (T)
Tx= primary tumor cannot be assessed To= no evidence of primary tumor Tis= carcinoma in situ (barely seen) T1-4= increasing size and/or local extent of the primary tumor
Staging of regional lymph node (N)
Nx= regional lymph node cannot be assessed No= no regional lymph node metastasis N1-3= increasing involvement of regional lymph node
Staging of distant metastasis (M)
Mx= presence of distant metastasis cannot be assessed Mo= no distant metastasis M2= distant metastasis
What is the main mechanism of carcinogensis?
oncogene activation
Oncogenes are either __ or __ in all cells.
expressed or suppressed
Overexpression occurs with ___ DNA that results in ___ suppressor genes.
damaged, damaged
Cancer development depends on…
- exposure to carcinogens
- genetic predisposition
- immune function (HIV, organ transplants, medications, etc.)
Chemical carcinogens include:
tobacco, alcohol
Physical carcinogens include:
radiation (damages DNA), chronic irritation
Viral carcinogens include:
onocoviruses (HPV causing cervical cancer, hepatitis B causing liver cancer, Epstein-Barr virus causing lymphoma, etc.)
Dietary factors include:
low fiber intake, high intake of red meat
preventative measures include eating green leafy vegetables
Personal factors include:
immune function, age (because we are living longer), genetic risk
What are the warning signs?
C- changes in bowel or bladder habits A- a sore that does not heal U- unusual bleeding or discharge T- thickening or lump in breast or elsewhere I- indigestion or difficulty swallowing O- obvious change in wart or mole N- nagging cough or hoarseness
Primary cancer prevention include:
- avoidance of known potential carcinogens
- modification of associated factors
- removal of “at risk” tissue (moles, colon polyps)
- chemoprevention
- vaccination
Secondary cancer prevention include:
- regular screenings (pap smear, skin check, mammography, beast examination, rectal examination)
- genetic screening
