Cancer Biomarkers Flashcards Preview

SSC- Biology of Cancer > Cancer Biomarkers > Flashcards

Flashcards in Cancer Biomarkers Deck (53)
1

Define the term cancer biomarker

A substance or process that is indicative of the presence of cancer in the body 

2

What are the uses of cancer biomarkers in practice? 

  • Risk/screening 
  • Prognosis
  • Prediction (response to treatment)
  • Recurrence/monitoring
  • Diagnosis
  • Pharmacodynamics

 

3

What are the categories of biomolecules that can be cancer biomarkers

  • Genetic
  • Epigenetic
  • Proteomic
  • Glycomic

 

4

What are the genetic cancer biomarkers? 

  • DNA mutations 
  • mRNA expression

 

5

What are the epigenetic cancer biomarkers? 

  • DNA methylation
  • Histone methylation
  • miRNA gene silencing

 

6

What are the proteomic cancer biomarkers? 

  • Protein levels
  • PTM

7

What are the glycomic cancer biomarkers? 

Glucose metabolism 

8

What sources can be tested for cancer biomarkers? 

  • Blood
  • Fine-needle aspirates
  • Fresh tissue
  • Frozen tissue
  • FFPE 

 

9

What are the features of an ideal cancer biomarker? 

  • Specific
  • Sensitive
  • Predictive
  • Robust
  • Reflect kinetics
  • Minimally invasive
  • Clinical importance

 

10

What should a cancer biomarker be specific to? 

  • Disease type
  • Disease stage 

 

11

How sensitive should the ideal biomarker be? 

Ideally should detect a single molecule 

12

What should the ideal biomarker be predictive of? 

  • Stratification
  • Treatment response
  • Recurrence

 

13

What factors are considered when deciding if a biomarker is robust? 

  • Fast
  • Simple
  • Cheap

 

14

What features must biomarkers have if they are to be used for cancer screening? 

  • Must be highly specific 
  • Must be able to clearly reflect different stages of the disease
  • Must be easily detected without complicated medical procedures
  • Method of screening must be cost effective

 

15

Why must cancer biomarkers used for screening be highly specific? 

To minimise false positives and negatives

16

What markers are good targets for application of early screening? 

Markers released to the serum and urine

17

What is prostate specific antigen produced by? 

Epithelial cells of the prostate

18

What levels of PSA are considered suspicious? 

4-10ng/ml 

19

What is required when PSA is 4-10ng/ml? 

Biopsy 

20

How is PSA used in risk stratification? 

Used to stratify patients into low, intermediate, or high risk for having/developing metastatic disease, or dying of prostate cancer. It is used in conjunction with two other parameters - grade (Gleason grading) and stage (imaging)

 

 

21

Where is HPV detected? 

Almost all cases of cervical cancer 

22

How are cervical cells collected? 

Using a Pap smear 

23

Who is screened for cervical cancer in the UK? 

Women aged 25 to 64 years - 25-49 years screened every 3 years, 50-64 screened every 5 years 

24

How is cancer traditionally diagnosed? 

Using tissue biopsy, on which immunohistochemistry and pathological evaluation are performed 

25

What is the problem with using biopsy to diagnose cancer? 

  • Highly invasive
  • Expensive

 

 

26

Define diagnostic biomarkers

Substances that are produced by cancer, or by other cells of the body, in response to cancer or certain benign conditions. 

27

Are tumour markers made by normal cells? 

Most are, however are produced much higher levels in cancerous conditions 

28

Give 6 examples of diagnostic biomarkers

  • Alpha-fetoprotein in liver cancer
  • Cancer antigen 125 in ovarian cancer
  • CA15-3 in metastatic breast cancer
  • Carbohydrate antigen 19-9 in colorectal cancer
  • Carcinoembryonic antigen in pancreatic cancer
  • Prostate specific antigen in prostate cancer 

 

29

Give an example of a genetic diagnostic biomaker 

BCR-ABL in CML (chronic myelogenous leukaemia) 

30

What % of patients with CML harbour a BCR-ABL translocation? 

95%

31

What drug targets BCL-ABL? 

Imatinib 

32

What is a prognostic biomarker? 

Indicates the likely course of the disease in an untreated individual 

33

What is the purpose of a predictive biomarker?

It identifies subpopulations of patients who are most likely to respond to a given therapy 

34

Why are predictive biomarkers clinically useful? 

  • Predictive biomarker driven cancer therapy reduces the unnecessary treatment and adverse effects
  • Can quickly highlight acquired resistance to therapy

 

35

Why is it important to reduce unnecessary treatment and adverse effects? 

  • Safer - Certain chemotherapy regimens result in death rates in the range of 0.5-2.0%, and 30-40% patients experience grade 3 or 4 toxic effects
  •  More clinical benefit
  • More cost effective

 

36

Give three examples of predictive biomarkers

  • ERBB2 amplification
  • ECFR mutation
  • BRAF mutation 

 

37

What is ERBB2 mutation a marker for? 

Highly aggressive breast cancers 

38

What is ERBB2 amplification targeed by? 

Trastuzumab (Herceptin)

39

What is mutated EGFR indicative of? 

Response to erlotinib in NSCLC

40

What is BRAF mutation indicative of? 

Response to vemurafenib in metastatic melanoma

41

What is cell free DNA derived from? 

  • Apoptosis
  • Necrosis
  • Active secretion

 

42

When are elevated levels of cell free DNA seen? 

In tumour cell turnover

43

What somatic alterations might occur in cell free DNA? 

  • Point mutations
  • CNV 
  • Structural rearrangements 
  • Methylation of DNA

 

44

Give an example of where cell free DNA can be used as a prognostic biomarker

ESR1 mutations in metastatic breast cancer 

45

What prognostic information can be determined from the presence of ESR1 cell free DNA? 

  • Those with the mutation who had prior exposure to AIs are resistant to therapy
  • Reduced progression free survival in ES1 mutation positive patients

 

46

How do circulating tumour cells (CTCs) get into the bloodstream? 

They are shed 

47

What is the clinical use of CTCs? 

  • Can be prognostic and predictive
  • Extremely useful monitoring tool 

 

48

What is the problem with circulating CTCs as a clinical tool? 

  • Difficult to isolate
  • Rare

49

What tools can be used to analyse CTCs? 

  • Immunostatin
  • FISH
  • Sequence
  • qRT-PCR
  • Expression analysis
  • Cell culture

 

50

What can circulating miRNAs be used as? 

  • Diagnostic biomarkers
  • Prognostic biomarkers
  • Predictive biomakers

 

51

What are the applications of miRNAs as diagnostic biomarkers? 

  • Monitor asymptomatic high-risk individuals
  • Identification of early-stage cancer
  • Discriminate between benign and malignant disease

 

52

What are the applications of miRNAs as prognostic biomarkers? 

  • Predict disease outcome
  • Predict progression-free and overall survival
  • Discriminate between benign and malignant disease

 

53

What are the applications of miRNAs as predictive biomakers? 

  • Monitor sensitivity to therapy and therapy response
  • Aid treatment decisions