Role of the Lab in the Diagnosis and Management of Tumours Flashcards Preview

SSC- Biology of Cancer > Role of the Lab in the Diagnosis and Management of Tumours > Flashcards

Flashcards in Role of the Lab in the Diagnosis and Management of Tumours Deck (77)
1

What is the gold standard in the diagnosis of cancer? 

Histology

2

What % of the work of a histology lab is convered with the diagnosis and treatment of cancer? 

70%

3

Why is it important that cancer diagnoses are made correctly? 

False positives and negatives are potentially disastarous and expensive 

4

Why might false positive cancer results be disasterous? 

A diagnosis of cancer can lead to radical treatment that is disfiguring or harmful 

5

Why can false negative cancer results be potentially disastrous? 

Because the patient will come back with more advanced tumours with a worse prognosis

6

Why are most cancers easily diagnosed histologically? 

Because most cases show histological features that are at either end of the benign-malignant spectrum 

7

What happens when cases are in the middle of the benign-malignant spectum histologically? 

It produces problems of diagnosis, and therefore management 

8

What are the categories of samples sent for cancer diagnosis? 

  • Tissue
  • Cytology

 

9

What forms of tissue sample might be received for histological testing? 

  • Diagnostic biopsy
  • Excisional specimen 

 

10

What is the main purpose of diagnostic biopsies? 

Diagnosis

11

Give two examples of methods of obtaining diagnostic biopsies

  • Incisional 
  • Needle core

 

12

What is the main purpose of obtaining excisional specimens

Done with curative intent 

13

What tissues are amenable to histological evaluation? 

All 

14

What is evaluated in cytology? 

Cells suspended in fluid

15

What are the ways of obtaining cytology samples? 

  • Exfoliation
  • Aspiration

 

16

How can cells be exfoliated? 

  • Can be shed - cells fall off a surface
  • Can be scraped off a surface

 

17

Give 4 examples of fluids that cells are shed into

  • Sputum
  • Urine
  • Pleural 
  • Ascitic

 

18

What is the problem with using cells that have been shed in diagnosis? 

Cells usually degenerate, so cancer pick-up rate is low 

19

How does the pick-up rate of cancer differ between shed cells and scraped cells? 

The scraped cells are intact and viable, so the pick-up rate is higher

20

When is an aspirate sample taken? 

When no surface is available for exfoliation 

21

Give 3 locations that an aspirate sample would be taken from

  • Accessible lump
  • Breast
  • Lymph node

 

22

How is an aspirate sample collected? al

With a needle into a lump, free hand - without guidance

23

How is an aspirate sample collected? 

Under imaging guidance

24

Give three locations where an aspirate sample would be obtained

  • Inaccessible lump
  • Liver
  • Pancreas

 

25

What is initially reported on when a histologist obtains a specimen? 

A macroscopic description of; 

  • Tumour
  • Apperance
  • Size
  • Spread

 

26

Why is tissue resected during cancer surgery inked? 

To demonstrate the excision margin when you look at it down the microscope 

27

What happens if a cancer extends to the excision margin? 

Probably need further treatment 

28

How is the tumour specimen further divided from its original form? 

Blocks are taken from areas of interest 

29

What happens to the tissue blocks cut from the specimen? 

They are impregnanted with wax to support tissue, and 4μm sections are cut 

30

How are the 4μm sections prepared for microscope visualisation? 

They are mounted on a glass slide and stained 

31

What factors will the histology report consider? 

  • Is there a lesion? 
  • Is it malignant? 
  • What sort of malignancy? 
  • How malignant is it? (Grade)
  • How far has it spread? (Stage)
  • Is it all out? 

 

32

What are the categories in the histological criteria of malignancy? 

  • Tissue changes
  • Cytological changes 

 

33

What are the tissue changes in the histological criteria of malignancy? 

  • Dysplasia
  • Invasion
  • Infiltrative margin 

 

34

What are the cytological changes in the histological criteria of malignancy? 

  • Nuclear pleomorphism
  • Nuclear size
  • Nuclear shape
  • Nuclear staining
  • Increased proliferation
  • Increased number of mitotic figures
  • Abnormal mitotic figures

 

35

What are tumours named from? 

The tissue in which they are derived

36

What are the potential histogenic classifications of tumours? 

  • Squamous
  • Glandular
  • Lymphoid
  • Melanocytic

 

37

What kind of classification may be more useful than histogenic classification in the future? 

Molecular classification, e.g. Braf +ve, HPV associated etc 

38

Histologically, what can help determine what sort of malignancy it is? 

  • Architectural arrangement
  • Cytological differentiation 

 

39

What features are considered in cytological differentiation? 

  • Morphology
  • Protein expression

 

40

What may be found when looking at morphology of malignant cells? 

  • Desmosomes
  • Mucin
  • Melanin

41

What may be found when looking at protein expression in malignant cells? 

  • Filaments
  • Low or high molecular weight cytokeratins
  • Specific protein products
  • Thyroglobulin
  • Enzyme production

 

42

What is the importance of the cancers grade? 

It provides important prognostic information about some cancers 

43

What is a cancer grade based on? 

Degree of differentiation 

44

How is a cancer grade determined? 

Mixture of score and subjective assessment, considering; 

  • Proliferation
  • Architectural differentiation
  • Pleomorphism 

 

45

What is the best predictor of prognosis in most cancers? 

Stage 

46

What does stage consider? 

The extent of the spread 

47

What is the importance of knowing the cancer stage? 

It provides vital information for making management decisions 

48

Where to carcinomas spread to first? 

Lymph nodes 

49

Where do sarcomas spread to first? 

Blood stream

50

How do sarcomas spread? 

Via the blood stream 

51

What needs to be assessed in order to determine the cancer stage? 

  • Primary tumour
  • Draining lymph nodes
  • Distant spread

 

52

What happens when you cannot assess the primary tumour? 

It is considered to be Tx

53

What happens if lymph nodes are found to be involved in cancer? 

Clearance

54

What happens if no involved nodes are found on examination or imaging? 

Targeted lymph node sampling

55

What is typically done to lymph nodes in breast cancer? 

Axillary clearance 

56

What is the problem of axillary clearance treatment in breast cancer? 

There is significant morbidity from lymphoedema

57

When is sentinal lymph node biopsy conducted in breast cancer? 

In clinical and USS negative cases 

58

What cancers is sentinal lymph node biopsy routinely used for? 

  • Breast
  • Melanoma
  • Penile SCC
  • Head and neck SCC

59

What happens in a sentinal lymph node biopsy? 

You inject the tumour with a dye containing a short half life radioactive isotope to determine the first draining lymph node. You would then remove and assess this lymph node. If there is no cancer, then the patient does not need a lymph not clearance. If there is, need lymph node clearance

 

 

60

What should be reported on when considering the margins in cancers? 

How big the margins are, and if the margins are cleared, close, or involved 

61

When might the margins in cancer exicision be left intentionally small? 

When there is intent for plastic surgery - have to balance getting clearance with serious deformity 

62

Give an example of a technique that can be employed when trying to make margins as small as possible

Moh's micrographic surgery 

63

What happens when the margins are involved? 

Further excision or radiotherapy 

64

Other than light microscopy, what other lab techniques can be used to investigate a tumour? 

  • Histochemical stains
  • Electron microscopy
  • Immunohistochemistry
  • PCR
  • In situ hydridisation
  • Cytogenetics

 

65

How can histochemical stains be useful in the diagnosis of cancer? 

  • Can help characterise the tissue components, e.g. collagen, melanin 
  • Can detect infection

 

66

How can PCR be useful in the diagnosis of cancer? 

  • Can detect monoclonality 
  • Can detect some infections 

 

67

How can in situ hybridisation be useful in diagnosing cancer? 

Can use specific probes for RNA or DNA to detect clonality 

68

What can be looked for using cytogenetics? 

Translocations 

69

How is immunohistochemistry conducted? 

  1. Antibodies bind to specific proteins in tissues, and so can be applied to tissue sections and detected via colour producing peroxidase reaction
  2. Antigens of interest are injected into animals to stimulate the immune response 

70

What can biological markers be used to determine? 

Therapy 

71

How can protein expression be characterised in the lab? 

Using immunohistochemistry 

72

Give an example of where steroid receptor status might be important

Breast cancer - oestrogen receptor expression predicts response to hormone therapy

73

Why does oestrogen receptor expression predict the response to hormone therapy? 

Because some tumours are dependant on oestrogen for growth (oestrogen regulates genes that promote growth), and detection of nuclear receptor indicates oestrogend dependance. If the tumour is dependant on oestrogen, blocking it will cause its death 

74

What is HER-2? 

A member of the ECG receptor family. It is a tyrosine kinase which promotes cell growth 

75

What % of breast cancers have HER-2 gene amplification? 

20-30%

76

What does gene amplification of HER-2 lead to? 

Uncontrolled cell growth 

77

Why is it important to know HER-2 status in breast cancer? 

  • HER-2 overexpression is a poor prognostic marker
  • Monoclonal antibodies to Her 2 inhibits Her 2 activity, and this treatment (herceptin) leads to a dramatic improvement in survival