Neoplasia Flashcards
(108 cards)
1
Q
What are disorders of growth due to?
A
- Abnormalities in regulations of cell size -> reduction in tissue mass
- Cell proliferation -> increases in tissue mass
- Differentiation resulting in abnormality of tissue mass/function/morphological appearance -> changes in tissue mass
2
Q
What are the 3 types of reduction in tissue mass?
A
- Agenesis - congenital absence (unilateral renal agenesis)
- Hypoplasia - congenital reduction in size (testes in Klinefeleters)
- Atrophy - shrinkage due to decreased size of cells (disuse)
3
Q
What are the 3 types of increases in tissue mass?
A
- Hyperplasia - increase in number of cells
- Hypertrophy of cells - increase in size of cells (permanent cells cannot increase cell number)
- Hypertrophy of parts - increase in size (may be hyperplastic or hypertrophic)
4
Q
What are the 2 changes in tissue mass?
A
- Metaplasia - change in type of mature tissue
- Dysplasia - partial transformation to malignancy
5
Q
What kind of change is columnar epithelium -> stratified squamous in smokers?
A
Metaplasia (endothelium -> endothelial type of adjacent tissue)
6
Q
Are metaplasias reversible? Malignant?
A
- Benign and generally reversible
- Some types carry increased risk of malignancy (may be due to acquired genetic abnormalities, or due to irritant stimuli + tissue damage)
7
Q
Are dysplasias malignant?
A
Genetic alteration to cell w/ loss of tumor supressor genes (and/or activation of oncogenes) but NOT sufficient for malignancy
- May occur w/ increase in tissue mass, or may be associated w/ microscopic lesion
8
Q
What is the extreme end of dysplasia?
A
Carcinoma in situ
9
Q
Identify the type of disorder of growth
A
- Hyperplasia
- Mild dysplasia
- Carcinoma in situ (severe dysplasia)
- Cancer (invasive)
10
Q
What does neoplasm literally mean?
A
“New growth”
- Abnormal mass of tissue that results when cells divide more than they should/do not die when they should
- Also called a tumor
11
Q
Are neoplasms benign or malignant?
A
May be both
- Benign neoplasia = loss of control -> stable, non-spreading mass
- Malignant neoplasia = more control loss -> expansion, infiltration, metastasis
12
Q
What is severe displasia?
A
Flat neoplastic change that is typically precancerous
13
Q
What is a tumor?
A
Neoplastic mass of cells (benign/malignant)
14
Q
What is cancer?
A
Malignant neoplasm
- Latin “crab” - seize upon adjacent tissues w/ pincher-like outgrowths
- Does not describe biological behavior (slow growing/indolent v. spread rapidly to many parts of body/rapidly cause death)
15
Q
What are the 2 mechanisms by which cancer is capable of spreading throughout the body?
A
- Invasion - direct migration/penetration by cancer cells into neighboring tissues
- Metastasis - penetration into lymphatic/blood vessels -> circulate throughout bloodstream -> invade normal tissues elsewhere in body
16
Q
Who was the 1st to recognize that cancer (and all disease) was a cellular disorder and it could be dx’d at microscopic level based on cellular appearance/arrangement?
A
Virchow
17
Q
How are cancer cells clonal?
A
All cancerous cells in a tumor are derived from a single cell
- Single cell -> cancerous cell occurs in steps w/ each step governed by a mutation
- Several subclones may appear before one that has cancerous characteristics
18
Q
What are characteristics of a benign neoplasm?
A
- Well-defined margins of tumor (encapsulated)
- Neoplastic cells grow only locally
- Slow rate of growth, may cease
- Generally have good pronosis (lead only rarely to death)
19
Q
What are characteristics of a malignant neoplasm?
A
- Poorly defined margins of tumor (infiltrative)
- Rapid rate of growth, progressive
- Neoplastic cells growing into and destroying surrounding tissue (morbidity)
- Major cause of death (mortality)
20
Q
What does the incidence of each type of cancer vary according to?
A
Age, gender, social class, ethnic origin, geographical location
21
Q
T or F: Most cancers are age related.
A
T; more yrs of cell divison, cancer evolves slowly due to prolonged exposure to environmental carcinogens
22
Q
How is cancer distributed between genders?
A
Cancer used to be more common in females than males (b/c of freq of cervical and breast CA, and rarity of lung cancer) -> now reversed in most countries
- CAs that have higher incidence in females = gall bladder, thyroid, malignant melanoma of skin
23
Q
What has been found in population studies of cancer incidence?
A
Cancers arise w/ diff frequencies in diff areas of the world
- Japan = stomach cancer
- US = colon cancer
- Australia = skin
- Japanese fams that move to US -> higher rate of colon cancer/lower rate of stomach cancer (NOT just heredity -> could involve cultural, behavioral, envir factors)
24
Q
What is a low-strength type of radiation that can cause cancer?
A
Sunlight (UV radiation)
25
What is a high-strength form of radiation that can increase rates of cancer?
X-rays or radiation emitted from unstable atoms called radioisotopes
26
What are chemicals and radiation that are capable of triggering the development of cancer called?
Carcinogens
27
Why do carcinogens have a "lag time"?
They act through a multistep process that initiates a series of genetic mutations and stimulates cells to proliferate (this requires a prolonged period of time)
* Young ppl exposed to carcinogens from smoking cigarettes generally don't develop cancer for 20-30 yrs
28
How do cancer viruses cause cells to become malignant?
Some of the viral genetic info carried in the nuclei acids is inserted into the chromosomes of the infected cell
* Viruses can't reproduce on their own, they enter into living cells -\> infected cell to produce more copies of the virus (in this case more copies of the cancer)
29
People who develop AIDs after being infected w/ HIV are at high risk for developing what type of cancer?
Kaposi's sarcoma - malignant tumor of blood vessels located in the skin
* Not directly caused by HIV, but immune deficiency makes people more susceptible to viral infx called KSHV (Kaposi's sarcoma-associated herpes virus)
30
What bacteria has been associated w/ the development of cancer?
**H. pylori** (which causes stomach ulcers) -\> increased risk for stomach cancer
31
What percentage of people w/ no family h/o the disease does cancer occur in?
80-90%
32
What percentage of breast cancers are thought to be due to a "breast CA susceptibility gene"?
5%
33
What type of cancer does hereditary retinoblastoma increase the risk for?
Retinoblastoma
34
What type of cancer does xeroderma pigmentosum increase the risk for?
Skin
35
What type of cancer does Wilms' tumor increase the risk for?
Kidney
36
What type of cancer does Li-Fraumeni syndrome increase the risk for?
Sarcomas, brain, breast, leukemia
37
What type of cancer does familial adenomatous polyposis increase the risk for?
Colon, rectum
38
What type of cancer does Paget's disease of bone increase the risk for?
Bone
39
What type of cancer does Fanconi's aplastic anemia increase the risk for?
Leukemia, liver, skin
40
What is the greatest public health hazard among various factors that cause cancer?
Tobacco
* Contains \>24 diff chemicals capable of causing cancer
* 80-90% of lung cancers
41
The prefix "**adeno**" means the cancer began its unchecked growth where?
Gland cells
42
The prefix "chondro" means the cancer began its unchecked growth where?
Cartilage cells
43
The prefix "erythro" means the cancer began its unchecked growth where?
RBCs
44
The prefix "hemangio" means the cancer began its unchecked growth where?
Blood vessel cells
45
The prefix "hepato" means the cancer began its unchecked growth where?
Liver cells
46
The prefix "lipo-" means the cancer began its unchecked growth where?
Fat cells
47
The prefix "lympho" means the cancer began its unchecked growth where?
Lymphocyte cells
48
The prefix "melano" means the cancer began its unchecked growth where?
Pigment cells
49
The prefix "myelo" means the cancer began its unchecked growth where?
Bone marrow cells
50
The prefix "myo" means the cancer began its unchecked growth where?
Muscle cells
51
The prefix "osteo" means the cancer began its unchecked growth where?
Bone cells
52
What are the most common types of cancer? Where do they arise?
**Carcinomas**; from cells that cover external/internal body surfaces
* Lung, breast, colon = most frequent CAs of this type in the US
53
What cancers arise from cells found in the supporting tissues of the body (bone, cartilage, fat, CT, and muscle)?
**Sarcomas**
54
What are cancers that arise in the lymph nodes/tissues of the body's immune sx called?
**Lymphomas**
55
What are cancers of the immature blood cells that grow in the bone marrow and tend to accumulate in large #s in the bloodstream called?
**Leukemias**
56
How can malignancy of carcinomas be diagnosed?
Invasion through tissue layers (basement membrane, muscularis mucosae)
57
How do carcinomas typically spread?
By lymphatics to lymph nodes, then later via blood stream to liver, other viscera and bones
58
What is the tx for carcinomas?
Surgical resection (response to radiation/chemotherapy varies w/ type)
59
How do carcinoma cells grow?
As cohesive groups of polygonal cells that may produce keratin (squamous cell) or mucin (adenocarcinoma)
* Cells stain for epithelial cell markers - cytokeratin, epithelial membrane antigen
60
How do **melanocytic tumors** spread?
Through lymphatics to regional lymph nodes, and via the bloodstream to a number of sites (skin, brain, viscera - small bowel, spleen)
61
How are melanocytic tumors treated?
By surgery, w/ radiotherapy and chemotherapy in disseminated cases
62
How are melanoma cells characterized?
They are round or spindle-shaped w/ nuclear enlargement, pleomorphism + high mitotic activity
* Fine brown melanin may be seen in cytoplasm
63
Are **connective tissue tumors** common?
Benign CT tumors are very common particularly (**lipomas**) while sarcomas are rare (1% of malignant tumors)
64
Where do **sarcomas** typically occur? How do they spread?
* In the deep tissues of the limbs/retroperitoneum, less commonly in head/neck/viscera
* Spread through blood stream (lymph node involvment is rare)
65
How are sarcomas treated?
Resection combined w/ radiation + chemotherapy
66
How are sarcoma cells characterized?
More cellular than normal CTs -\> these cells may be spindle-shaped, round or bizarre and pleomorphic
67
What are **lymphomas**?
Common tumors that may also involve extranodal sites (skin, stomach, small intestine)
* NO in-situ/benign phase is recognizable
* Tx: chemotherapy + radiotherapy w/ resection for localized extranodal lymphomas
* Consist of masses of non-cohesive round cells
68
What is **leukemia**?
Neoplasms of hematopoietic cells that infiltrate/replace bone marrow
* May arise from extramedullary sites sometimes
* Tx: chemotherapy
69
What are **glial tumors**?
Arise from astrocytes, oligodendrocytes and ependymal cells
* Most are diffusely infiltrative, but respond to radiation + chemo
* Prognosis varies according to grade
70
What is a **teratoma**?
Overgrowth of very specific cell
71
What are the 3 kinds of genes that are targets for carcinogenic transformation?
1. **Proto-oncogenes**
2. **Tumor suppressor genes**
3. **DNA repair genes**
72
What kinds of genes promote cell growth and require the alteration of only 1 allele to create out of control cellular growth (dominant gene)?
**Proto-oncogenes**
73
What kinds of genes inhibit cell growth and require alteration of **both** alleles to affect cell growth (recessive oncogenes)?
**Tumor supressor genes**
74
What are genes that code for proteins whose normal function is to correct errors that arise when cells duplicate their DNA prior to cell division?
**DNA repair genes**
75
What does **tumor progression** refer to?
Ability of transformed cells to acquire further abnormal characteristics over time, independent of tumor size
* Includes ability to invade, metastatic spread, further anaplasia
* These characteristics are acquired through mutations within the tumor leading to subgroups of cells w/ varying characteristics
76
At the time of diagnosis, most tumors are ______ and have multiple cell lines present.
**Heterogenous**
77
What may contribute to the increased instability of DNA in tumors?
Absence of p53
* Tumor supressor genes = normal genes whose ABSENCE can lead to cancer
* p53 is a tumor supressor gene that can trigger cell suicide (apoptosis) in cells that have undergone DNA damage
78
How are proto-oncogenes part of normal cell growth?
GFs bind to receptors on cell surface -\> activate signaling ezymes inside the cell -\> **activate special proteins called transcription factors inside the cell's nucleus** -\> "turn on" genes required for cell growth/proliferation
79
What are 3 ways that proto-oncogenes becomes oncogenes?
1. A mutation
2. A chromosomal translocation
3. An increase in amount of certain proteins (increase protein expression/gene duplication)
80
What can mutations in DNA repair genes lead to?
Failure in repair -\> subsequent mutations accumulate
81
What gene defect exists in xeroderma pigmentosum?
Infected defect in a DNA repair gene -\> cannot effectively repair DNA damage that normally occurs when skin cells are exposed to sunlight -\> abnormally high incidence of skin cancer
82
How does cancer tend to involve multiple mutations?
Mutation inactivates suppressor gene -\> cells proliferate -\> mutations inactive DNA repair genes -\> proto-oncogenes mutate to oncogenes -\> more mutations, more genetic instability, metastatic disease
83
What is peto's paradox?
Incidence of cancer in organisms does NOT relate to # of cells
* Elephants have 20 copies of TP53 and humans only have 1
84
What 3 things does tumor invasion require?
1. Attachment of cancer cell to basement membrane - laminin receptors and integrins are important (also in migration/adhesion to endothelial cells)
2. Proteolysis of basement membrane w/ hydrolytic enzymes
3. Migration through the gap into surrounding CTs
85
What is loss of basement membrane in malignancy due to?
Both a decrease in production of membrane components and an increased degradation by hydrolytic enzymes
86
What leads to firmness/fixation of a tumor?
Local spread is by direct invasion of surrounding tissues (note that some are more resistant)
87
What is the process whereby a tumor spreads to distant sites via lymphatic vessels, blood vessels, and through body cavities?
Metastasis
88
What are the steps of metastasis?
1. Invasion of CT matrix (stroma)
2. Invasion of blood + lymphatic vessels
3. Circulation of tumor cells
4. Invasion from blood vessels into tissues
5. Angiogenesis
89
How does cancer change its environment?
* Cancer cell loses receptors that normally respond to neighboring cells that call for growth to stop -\> tumors amplify their own supply of growth signals
* Flood their neigbors w/ other signals (cytokines) + enzymes (proteases) -\> destroys basement membrane + surrounding matrix
90
What is **lymphatic spread**?
* Tumor cells that invade a lymphatic vessel may colonize nearest lymph node -\> continue to spread from node to node -\> circulation
* Prognosis may depend on lymph node invasion
* Occurs mainly in epithelial malignancies
91
What is **venous spread**?
Direct route to distant sites
* Main route of dissemination of sarcomas (lymphatic spread rare)
* Involvement of liver (stomach, large bowel) is due to portal vein
92
How does cancer **spread through body cavities**?
* Usually in serosa-lined cavities, but also in the CSF (high grade gliomas)
* Spread through mucose-lined cavities has not been demonstrated
93
What is **spread by implantation**?
Iatrogenic spread/implantation facilitated by surgery
94
What tumors are the **lymph nodes** metastatic sites for?
Carcinomas, melanoma
95
What metastatizes in the **brain**?
Carcinomas, melanoma (perineural spread of prostate cancer)
96
What metastasizes in the **bone**?
Cancer of the breast, prostate, kidney, stomach
97
What metastasizes in the **liver**?
Abdominal carcinomas, ovarian, breast
98
What metastasizes in the **lung**?
Most tumors
99
What is the **tumor grade**?
Measure of the rate of tumor growth based on tumor histology
* Provides info regarding likely behavior of a tumor/responsiveness to tx
* Low number grade (grade I or II) = cancers w/ fewer cell abnormalities than those w/ higher numbers (grade III, IV)
100
What is the **tumor stage**?
Measure of the extent of the tumor, based on clinical/radiological/pathological features
* How large is the tumor/how deeply has it invaded surrounding tissues
* Have cancer cells spread to regional lymph nodes
* Has the cancer metastasized to other regions of body
101
What is the **clinical stage** based on?
Clinical and radiological grounds (before biopsy)
* Key part of deciding the best tx
* Also baseline used for comparison when looking at cancer's response to tx
102
What is the **pathological stage**?
Relies on what is learned about the cancer during surgery
* Often this is surgery to remove the cancer and nearby lymph nodes, but sometimes surgery may be done to just look at how much cancer is in the body and take out tissue samples
103
What is **stage 0**?
Carcinoma in situ - early form
* For colorectal cancer: only in the innermost lining of the colon or rectum
104
What is **stage I**?
Localized
* In colorectal cancer: cancer has not spread beyond inner wall of colon/rectum
105
What is **stage II**?
Early locally advanced
* In colorectal cancer: cancer has spread into the muscle layer of the colon/rectum
106
What is **stage III**?
Late locally advanced
* In colorectal cancer: cancer has spread to one + lymph nodes in the area
107
What is **stage IV**?
Metastasized
* In colorectal cancer: cancer has spread to other parts of the body, such as liver, lung or bones
* Does NOT depend on how deep the tumor has penetrated or if the disease has spread to the lymph nodes near the tumor
108
What are signs/sx of cancer?
1. Fatigue
2. Unexplained weight loss
3. Weakness
4. Dizziness
5. Fever
6. Pain
7. Skin changes
* Darker looking skin (hyperpigmentation)
* Yellowish skin/eyes (jaundice)
* Reddened skin (erythema)
* Pruritus
* Excessive hair growth
