Seminar 7 - Cancer biomarkers Flashcards
Define a biomarker.
A biological molecule found in blood, other bodily fluids, or tissues which is a sign of a normal or abnormal process, or of a disease or condition
What other names can be given to a biomarker?
- Molecular marker
2. Signature molecule
Define a cancer biomarker.
A substance or process that is indicative of the presence of cancer in the body
What biomaterials can be obtained from a blood sample?
- DNA/RNA
- miRNA
- Exosomes
- PSA
- CTCs
What are the advantages of a blood sample?
- Prognostic biomarkers
- Diagnostic BMs
- Minimally invasive
- Low cost
What are the disadvantages of obtaining biomaterials from a blood sample?
- Complex
- Patient variability- influenced by environment and current health status - e.g. infection or unrelated pre-existing disease
What biomaterials can be obtained from a tissue sample?
- DNA/RNA
- AMACR
- Histopathology/immunohistochemistry
- Gleason score
What are the disadvantages of obtaining biomaterials from a tissue sample?
- Highly invasive
- High cost
- Associated side effects due to method of acquiring sample
What are the advantages of obtaining a tissue sample?
- Prognostic and diagnostic biomarkers
2. Analysis of markers directly from the prostate
What biomaterials can be obtained from a urine sample?
- DNA/RNA
- miRNA
- Prostasomes/exosomes
- PCA3
- TMPRSS2: ERG
What are the advantages of a urine sample?
- Prognostic and diagnostic biomarkers
- Low cost
- Large volume
- Non-invasive
- Access to proteins directly from the prostate
What are the disadvantages of obtaining biomaterials from a urine sample?
- Low concentration of molecules
2. Variability among patients
State the features of an ideal biomarker.
- Specific - disease type and stage, specificity > 0.9
- Sensitive - sensitivity > 0.9, single molecule
- Robust - fast, simple, cheap
- Minimally invasive - blood, urine, saliva, CSF
- Reflect kinetics: pathologic process, therapy response
- Predictive - stratification, recurrence, treatment response
- Pre-clinical importance: validity in animal/human models
State the general stages of cancer development.
Dysplasia: pre-cancer Stage 0: Carcinoma in situ Stage 1: Localised Stage 2: Early locally advanced Stage 3: Late locally advanced Stage 4: Metastasised
Which TSGs are abnormally methylated in brain cancer?
- p16
- CDKN2B
- p14ARF
