Chapter 18- Tumor Immunology Flashcards
Composed of cell that is similar with the normal cells they are from but difference is that they have accelerated or dysregulated growth
Tumor
“Swelling”
Tumor
Cannot be eradicated because they are similar to tissue
Tumor
Tumor that doesn’t spread
Benign tumor
Dissemination of tumor, not normal function and death occurs
Metastasis
State the 4 stages/process of normal to malignant cell
1) induction phase / exposure
2) in situ phase / abnormal growth
3) invasion phase / malignancy
4) dissemination
In induction phase, there is exposure to?
Carcinogens
Oncogenic viruses
Radiation
Enlargement of organ
Dysplasia
Abnormal growth of tissue
Neoplasia
Where neoplasia happens BUT does not metastasize yet
In situ phase
Stage where cancer develops due to exposure
Induction phase
Phase where cell becomes malignant
Invasion phase
Best phase to detect tumor
Invasion phase
Phase where tumor is spread throughout the body
Dissemination
Dissemination throughout the body is done through the ____ and _____
Blood
Lymphatics
Classification of rumors
1) poorly differentiated tumors / anaplastic tumors
2) well differentiated tumors
Tumors similar to fetal or embryonic tissue
Poorly differentiated tumors
Another term for poorly differentiated tumors
Anaplastic tumors
Tumors similar to normal tissue
Well-differentiated tumors
the more aggressive type of tumor based on classification
Poorly differentiated tumor / anaplastic tumor
This is used to classify tumors by size, involvement, and detection
TNM system
What does the TNM system stand for?
T=Tumor Size
N= Node (lymph) involvement
M= Metastasis detection
Immune system monitoring tumor
Immunosurveillance
Immune system helps monitor tumor by the following:
1) NK cells, T cells, and macrophages infiltrated by the tumor
2) poor antigen presentation allow tumor cells to escape from T cells
3) medicines aimed in immune system to fight cancer is a success
Why can tumors be poorly immunogenic?
Because they are the same as body
Cytokines that stop tumors
Transforming Growth Factor-B
Mutations of cancer cells that are less immunogenic so they escape & mutate so that they won’t be controlled by the immune system anymore
Immunoediting
Antigens present in tumors and more in number compared to normal tissues
TAA (Tumor Associated Antigens)
Tumor Associated Antigens are from
Mutated genes
Viruses
Aberrant (wrong) expression of normal age
Fetal tissue and cancer is the same
Oncofetal Tumor Antigens
What are the principles of lab tests?
screening test
Diagnostic test
This detects undetectable / asymptomatic cancer
Screening test
This is done to know the differential diagnosis (stage, prognosis, therapy selection)
Diagnostic test
Probability calculation
Baye’s Theorem
A good cancer test is?
99% sensitivity (with disease)
95% specificity (without disease)
If population cancer is 0.1%?
98% of POSITIVE is False positive
If population cancer is 1%?
83% of POSITIVE is false positive
Is identified by clinician 75% of the time
Syndrome
If syndrome is identified by clinician 75% of the time and done again…
1.7% is False positive
High cancer prevalence being tested
Differential diagnosis
Low cancer prevalence being tested
Screening test
Has a high number of false positive
Screening test
Instances on when to use screening tests? Name 4
1) cancer has a large impact on society, therefore a need to screen people arises
2) if there is a marker with high sensitivity and specificity for use in screening
3) if tumor can be cured at an early stage
4) if cost and benefits suit the society
Name 2 benefits of screening test
Improves survival time
Less radical treatment for tumors detected earlier
Differential diagnosis of tumor type is done by?
Tissue morphology / cell morphology
Detection of tumor markers
Uses labeled antibody to detect antigen
Immunohistochemistry
Detects abnormal gene expression
FISH (Fluorescent In Situ Hybridization)
Uses nucleic acid probe
FISH
What does FISH use?
Nucleic acid probe
Is specific for prostate gland of men
PSA (Prostate Specific Antigen )
Increased in all prostate cancer
PSA prostate specific antigen
Give common tests for Tumor Marker Detection
1) stool occult blood
2) colonoscopy (for COLORECTAL CARCINOMA)
3) papanicolaou smear (CERVICAL CANCER)
4) x-Ray mammography (BREAST CANCER)
5) digital rectal exam (PROSTATE CANCER)
3 types of lab methods for cancer screening & diagnosis
1) gross and microscopic morphology of tumors
2) detection of antigen or protein tumor markers
3) DNA/RNA molecular diagnostics
Lab methods for cancer screening and diagnosis is chosen based on?
Convenience
Cost
Sensitivity
Specificity
What are used for final diagnosis?
1) cytogenetic studies
2) nucleic acid amplification techniques
3) fluorescent in situ hybridization (FISH)
Tests gene defects in various cancers
Cytogenetic studies
Detects small populations of cancer cells
Nucleic acid amplification techniques
Detects MUTATION, DELETION, and TRANSLOCATION
Nucleic acid amplification techniques
What is detected by Nucleic acid amplification techniques ? MDT
Mutation
Deletion
Translocation
Probes with flurophors that can bind to sequence of interest and apply it to cells
FISH
Marker for CHRONIC MYELOGENOUS LEUKEMIA
BCR-ABL
Present in MULTIPLE MYELOMA / other LYMPHOID MALIGNANCY
Monoclonal expression of B-Cell DNA rearrangement
Used for multiple testing of a sample for multiple genes
Microarray tests
A single chip with multiple nucleic acid tests
Microarray tests
Susceptible for breast, ovarian and prostate cancer
BRCA-1 & BRCA-2 Mutations
4 characteristics of an ideal tumor marker
1) produced by tumor / secreted into some biological fluid
2) long circulating half-life
3) elevated levels while disease is being treated & few false (+)
4) antigen is not present in people without disease so that there is decreased false (+)
what are the non-nucleic acid tumor markers?
Cell surface markers Proteins Oncofetal Antigen Carbohydrate antigen Blood group antigen Enzymes and Isoenzymes Hormones
Not really from the tumor; can also be a product of normal tissue
Tumor markers
Tumors are mostly detected using ____ due to its ____ BUT it may _____ due to its ____
ANTIBODY
SPECIFICITY
Cross react
Similarities
Antigen saturation of antibody inhibits cross linkage needed to view reaction
Prozone effect
Causes false decreased measurement;
Due to antigen excess can saturate antibody;
No sandwich configurations cannot form
High-Dose Hook Effect
False increase
False (+)
Already like a tumor
Heterophile antibody
Type of immunotherapy
Passive immunotherapy
Involves transfer of antibody, cytokines, cells to patients without it
Passive immunotherapy
Immunity comes from others
Passive immunotherapy
Allogenic transfer of cells
Graft vs. Leukemia
Cells from donors which can be immunized against tumors
T cells
Manipulates allogenic T cell to be vulnerable to a drug that will kill them before GVHD happens
Suicide switch
These are Harvested and expanded in vitro using IL-2 then give it to the patient
Autologous T-Cells
Antibody that can kill cancer cells without destroying adjacent cells
Antibody conjugates / IMMUNOTOXINS
