N339 Exam 1 Flashcards
Neoplasia
new growth (tumor)
Neoplasm
malignant growth (cancer)
______ is the 2nd leading cause of death in the US
Cancer
What are the top 3 new cancer types and leading causes of death (cancer types) in men and women?
Men: Protstate, lung/bronchus, colon/rectal
Women: Breast, lung/bronchus, colon/rectal
Anaplasia
cells don’t differentiate
Do daughter cells normally become more or less differentiated with each division?
daughter cells have less potential for differentiation
Each division of daughter cells becomes more specialized to that of adult tissue.
Do benign cells have an increased or decreased rate of division (mitosis)?
Benign cells have few mitosis (low rate of cell div, ie grow slower.
Do malignant cells have an increased or decreased rate of division?
increased rate, grow quickly.
What characteristic allows malignant cells to metasticize?
lack of cell adhesion
What is the difference b/w metastasis and infiltration?
metastasis-tumor sheds cells that leave originating organ and travel via lymph or vasc and invade new site.
infiltration-crablike extensions that indicate cancer w/in primary site of origin.
Are benign tumors are strictly localized. How do they remain at their primary site of origin?
The body is able to wall off benign tumors by activating fibroblasts that encapusulate the tumor.
Would you expect benign tissue/tumors to become necrotic? why or why not?
benign tissues grow so slowly that they become vascularized so don’t become necrotic vs malig grow so quick that they have necrotic core.
Angiogenesis
New blood vessels form from pre-existing vessels.
Is recurrence common after focalized treatment with benign tumors? with malignant?
Rare with benign
comml with malignant
Compare the histology of benign vs malignant tumors.
benign: typical of tissue of origin, few mitoses
malignant: anaplastic with abnormal cell size and shape, many mitoses
Compare the growth rate of benign vs malignant tumors.
benign: slow
malignant: rapid
Compare the localization/metastasis of benign vs. malignant tumors
benign: striclty local, often encapsulated, no metastases
malignant: infiltrative/ frequent metastases
Is tumor necrosis common or rare with benign vs maliganant tumors?
benign: rare
malignant: common
If tumor type ends in “oma” is it benign or malignant? what are the exceptions?
Oma: benign with exceptions:
carcinoma and sarcoma = cancer
Melanoma, lymphoma, hepatoma, leukemia, myeloma
What does the word “blast” indicate?
Daughter cell mutation
“1/3 of all cancer deaths are related to ______”
environment
Do the following increase or decrease cancer risk: and how?
- Tobacco Use
- Nutrition (fat, fiber, alcohol, antioxidants)
- Age
- tobacco bad: tars and nicotine cause genetic damage, 2nd hand smoke kills
- nutrition: Obese people have greater risk for cancer. Corr b/w obesity and cancer risk.
- Fiber is good. Enhances peristalsis and removal of toxins.
- Fat bad. assoc w/ lipoproteins, cholesterol etc.
- alcohol bad. Corr w/ hepatoma.
- antioxidants good. Limit amount of DNA damage by free radicals. spinach & blueberries!
- Age: longer we live, greater chance for mutation. Repair mechanisms and self destruction mechs slow. Ex. white cells decrease w/age (NK and leukocytes).
The risk of developing cancer increases with age. It is estimated that ___ have almost a 1 in 2 lifetime chance of developing cancer, whereas ____ have a little more than a 1 in 3 chance
men, women
Oncogenesis
process of tumor formation
Proto-oncogenes
normal genes that can mutate to form oncogenes Examples: Growth factors, cytoplasmic signaling pathways that govern cellular metabolism; transcription factors;
When proto-onc mutates it becomes an _______ or ______ gene.
oncogene or cancerous
Why factors contribute to proto -oncogene mutation?
1: oncogenic viruses
2: mutagenic event (Ex radiation exposure, cigarette smoke, UV light)
3: mutation of regulatory pathways
4: amplification of proto-oncogenes
What do Tumor suppressor genes do?
either repair DNA mutation or if can’t repair, then trigger apoptosis (programmed cell death).
What are angiogenic factors?
cytokines that flow thru interstit fluid to Blood vessels causing endothelial cells to undergo growth. Endothelial cells then grow new vessels that follow path of cytokine back to tumor to supply blood/nutrients.
If a mutation occurs in a daughter cell that has differentiated close to the normal functioning parent cell, what type of neoplasm has occurred?
well differentiatied, low malignancy
termed “low degree of malignancy”
If a mutation occurs in a daughter cell that hasnt differentiated close to that of the normal functioning parent cell, what type of neoplasm has occurred?
moderatley differentiated, moderate malignancy
If a mutation occurs in a daughter cell very early in differentiation or lacks differentiation, what type of neoplasm has occurred?
poorly differentiated, highly malig neoplasm
what is the relationship between differentiation, mutational and malignancy?
Inverse relationship: mutation occuring earlier in differentiation results in the highest the degree of malignancy
If a cell with normal P53 gene has DNA damage, what function does P53 perform?
P53 is a tumor suppressor gene. P53 will initiate cell cycle arrest, repair of the gene and if repair doesn’t work, P53 will activate genes responsible for celluar apoptosis.
In a cell lacking P53 or damaged P53 gene, what happens when gene mutation occurs?
no cell cycle arrest or repair, and no activation of apoptotic genes results in malignant tumor growth.
What are the 3 steps of Carcinogenesis?
Initiation
Promotion
Progression
What occurs during the initiation phase of carcinogenesis?
initiation: where the mutation occurs.
genetic mutations that inappropriately activate proto oncogens and inactivate tumor suppressor genes.
What occurs during the Promotion phase of carcinogenesis?
Mutant cells proliferate, possibly due to activation of another oncogene or inactivation of a tumor suppressor gene
What occurs during the Progression phase of Carcinogenesis?
Mutant, proliferating cells begin to exhibit malignant behavior (ie development of the cancerous phenotype)
Cancer is thought to develop when _______ become inappropriately activated in a cell or when ________ become inactivated. This change in gene function is usually due to _______ in the cell’s DNA.
proto-oncogenes
tumor suppressor gene
mutations
Mutant proto-oncogenes disrupt the intercellular communication pathway that normally regulates cell proliferation. This disruption may occur through abnormal production of what? (4)
growth factors
receptors
cytoplasmic signaling molecules
nuclear transcription factors.
Both copies of a tumor suppressor gene usually must be _______ to eliminate its function. ____________ inhibit cellular proliferation in various ways. The _____ serves as a “master brake” on cell proliferation by inhibiting transcription factors. ____ inhibits cell cycling when the cell is damaged to allow time for DNA repair. P53 is also important in initiating _______ (programmed cell death) of damaged or unwanted cells.
inactivated Tumor suppressor genes Rb protein P53 apoptosis
What are two types of carcinogenic agents?
Radiation and Oncogenic Viruses
What are two types of Radiation? provide examples.
Ionizing: contact w/ atomic bomb; assoc with leukemia; people that survived hiroshima had 30 fold increase in leukemia UV radiation (sunlight): tanning
Name 5 types of oncogenic viruses
- HPV- cervical carcinoma
- EBV- mono; in Africa EBV gives rise to Burkitts lymph (kids disease)
- HEP C and HBV: cause loss of hepatocytes, regenerate and more mitotic divisions lead to mutation
- HTLV-1 causes adult T cell leuk-lymph leuk occurs in blood system; lymphoma in lymph organs
- HIV causes Kaposi sarcoma; malignant
Name 5 chemical and/or environmental agents known to be carcinogenic to people (include what organ they affect).
- Cigarette smoke- polycyclic hydrocarbons (lungs)
- Asbestos- carcinogen causes mesothelioma in lungs; huge time lapse can occur b/w initiation and progression.
- Carbon tetrachloride- Mothballs
- insecticides, fungicides
- Smoked Foods- gastro and intestines
Full expression of cancer in a host is a multistep process. These steps have been described as ____, _____ and _______. The initiating event is usually from genetic _____ . Promotion refers to the stage in which the mutant cell is induced to ______. Progression is the stage during which the mutant, proliferating cells acquire properties that allow malignant ______.
initiation, promotion, and progression
mutations
proliferate
behavior
Identify 4 tumor markers.
PSA: rapid rise in PSA may be flag for prostate cancer
Thyroglobulin: hormone assoc w/ thyroid carcinoma increase in TG red flag for thyroid carcinoma.
Neuron-specific enolase: assoc with small cell carcinoma of lungs or neuroblastoma.
Monoclonal Ig- indicative of M. myeloma (cancer of B cells causes holes in bones)
Malignant cells produce specialized enzymes and receptors to enable them to escape their tissue of origin and ______ . The spread of tumors generally occurs by way of the ______ or ______.
metastasize
bloodstream
lymphatic vessels.
Tumor cells often lodge in the ________ of the organs that drain them, such as liver and lung. Some tumors appear to be directed to certain tissues.
capillary beds
___________ is the process by which tumors stimulate the growth of ________ to support the growth of the tumor. Tumors cannot grow larger than __ mm in diameter unless they grow blood vessels into the tumor to provide __________.
angiogenesis Angiogenesis blood vessels 2 oxygen and nutrients.
