Neoplasia Basics

Question 1

Define Neoplasia

Answer 1

Abnormal cell growth and differentiation.

NOTES
• Neoplasia is the process, neoplasm is the mass of cells or tumors (generally not malignant) but can be serious if in a location with limited space (cranium, major organ)
• Most cases not reversible. Doesn’t progress or regress

*Anaplasia generally means malignant, neoplasia is just new growth though Ahmed calls it abnormal

Question 2

Distinguish between Benign and Malignant

Answer 2

See Table 8-2

Benign-
• Still abnormal, uncontrolled, slow growth.
• May stop or regress (regression not common)
• Partly differentiated (normally differentiated same as local tissue) non invasive (i.e not breaking down other tissue)

Malignant-
• Disorderly, rapid growth, poorly differentiated cells
• Invasive and damaging
• Cancer- Malignant tumor caused by mutated genes

Question 3

4 Categories of Genes Associated with Neoplasia

Answer 3

1) TP53 Genes
2) DNA repair Genes (spellcheck)
3) Proto-Oncogenes (go/start)
4) Tumor Suppressor Genes (stop)
Notes: Normal= cell division controlled by genes (start/stop/spellcheck). Genes located on chromosomes (as triplet code using ATCG) always code for proteins. Cell makes the protein and proteins do all the jobs. Any defective genes that brings about uncontrolled growth are called onco genes. Oncogenes bring about malignant growth.

Question 4

TP53 Genes

Answer 4

… cause apoptosis when DNA is damaged

NOTES:
• All cells have it
• This refers to the gene (P53 is the protein)
• 50% of CA have a defective TP53

Question 5

Describe the start, stop and Spell check Genes

Answer 5

DNA repair genes (spell check) – general group of genes
• Read code – finds errors – corrects them
• Repairs all genes
• A major target of carcinogens

Proto- oncogenes (“go” genes)
• Increase cell division
• if mutated – uncontrolled division – increase growth

Tumor suppressor Genes- (stop genes)
• Decrease of cell division
• If mutated can cause uninhibited cell division and increased growth

Question 6

3 Basic Naming Rules for Tumors (Type and suffix)

Answer 6

Benign tumors use suffix “oma”

Malignant use suffix
• Carcinoma (if epithelial tissue)
• Sarcoma (if mesenchyme tissue) * mesenchyme is an embryonic tissue that in adults gives rise to all other tissue muscle, connective, adipose)

Question 7

Basic rules of Tumor Growth Curve

Answer 7

Fig 8-5
• Generally 10yrs to clinically detectable
• 30 doublings – 1 billion cells
• Tumors on average double every 100 days

Question 8

3 Methods of Spread

Answer 8

• Extension and Invasion- Growing locally and killing local cells
• Seeding in body cavities- Fall off and land on other organs (namely Abd cavity) The new site is the secondary site
• Metastasis- via blood and lymph

Question 9

Define Metastasis

Answer 9

• Spread of CA cells from 1* to a 2* site. Via blood and lymph (distinction of route vs site)

NOTES
• Lymphatic tissue is the common 2* site (especially carcinoma)
o Then in order: liver, lungs, bone and brain (especially sarcomas)
o Generally 2* site is well vascularized and large in size

Question 10

3 Stages of Metastasis and Description

Answer 10

Stage 1-
• Invades local tissue, Tumor releases in enzymes which break apart tissue at primary site
• Emboli (multiple groups of CA cells) Enter blood or lymph
o Most emboli are destroyed by immune response

Stage 2-
• Travel via blood and lymph until they reach an area of resistance (i.e. capillary bed)
• Must attach to a suitable site- cells actually sense the site for suitability
o Use mediators- cytokines and growth factors

Stage 3- Angiogenesis (formation of new blood vessels) and cell growth at secondary site
• Cells remain the same, destroys local cells
• Platelets can mask emboli- FIg 8-4

Question 11

Describe TNM Stages of Tumors

Answer 11

Staging (clinical criteria) Global TNM system
o T [0-4] = size (o is no tumor)
o N (0-3) = regional lymph node involvement (extent of involvement , not specific number)
o M (0-1) = metastasis

o TNM(x) = can’t be assessed

Question 12

Describe the Grading of Tumors

Answer 12

Based on localized extension and invasion

Graded l-lV restrictive to extensive

Question 13

Standard Options for CA Tx

Answer 13

Depends on type of CA, patient specifics, and progression

Radiation, chemotherapy, surgery, immunotherapy, hormone therapy, or combination

Question 14

Describe the 3 most common CA TX’s- Radiation, Chemotherapy and Surgery

Answer 14

• Radiation – will damage other cell
o Necrosis via: Generation of free radicals, Disruption of DNA bonds

• Chemotherapy- Medications to target fast cell division. Often damages other cells, normally a cocktail of drugs
o Targets cell division, Prevents/slows growth of cells

• Surgery (Sx) –cleanest way of removing Ca
o Excise tumore (must remove ALL malignant cells)

Question 15

Describe Immunotherapy

Answer 15

o Uses cytokines and Abs (get immune system going artificially uses a particularly strong antigen)
o Stimulates IR to destroy CA cells
o Larger tumors cell growth can outpace IR

Question 16

Describe CA Hormone therapy

Answer 16

Tumors are supported/nurtured by hormones
o Use an anti / opposing hormone OR weird one- use hormone that is supporting tumor, provide hormone to reduce receptors on tumor and this disrupts regulatory function (For Hormone responsive tumors)

Question 17

Problems Associated with Therapy

Answer 17

• Focus- difficulties specifically targeting the tumor
• Normal cells (damage?)
• Recurrence (CA return)

Question 18

Compare Cell characteristic of benign vs malignant Tumors

Answer 18

BENIGN
Well-differentiated cells that resemble cells in the tissue of origin
MALIGNANT
Cells are undifferentiated, with ananplasia (reversion of cells to an immature or less differentiated form) and atypical structure that often bears little resemblance to cells in the tissue of origin

Question 19

Compare rate of growth in Benign and Malignant tumors

Answer 19

BENIGN
Usually progressive and slow; may come to a standstill or regress
MALIGNANT
Variable and depends on level of differentiation; the more anaplastic (less differentiated cells) the cells, the more rapid the rate of growth

Question 20

Compare mode of growth in Benign and Malignant tumors

Answer 20

BENIGN
Grows by expansion without evading the surrounding tissues; usually encapsulated
MALIGNANT
Grows by invasion, sending out processes that infiltrate the surrounding tissues

Question 21

Compare metastasis in Benign and Malignant tumors

Answer 21

BENIGN
Does not spread by metastasis
MALIGNANT
Gains access to blood and lymph channels to metastasize to other areas of the body