The grading and staging of tumours and the clinicopathological aspect of cancer Flashcards
1
Q
What is the difference between grading and staging?
A
- Grading = the degree of differentiation
- Staging = the extent that the tumour has spread
2
Q
Define tumour grading
A
- Degree of differentiation - similarity to tissue of origin
- Can only be assessed histologically
- Well differentiated tumours (grade 1) = resemble tissue of origin; behave less aggressively than poorly differentiated tumours (grade 3)
3
Q
How can we measure the stage of a tumour?
A
- Extent of tumour spread
- By tissue biopsy
- By imaging
4
Q
How do tumours spread?
A
- Directly into adjacent tissues (eg BCC of skin)
- Via lymphatics (breast/ colon)
- Blood vessels (renal cell, sarcomas, prostate)
- Along nerves (pancreas, prostate)
- across Coelomic cavities (stomach, ovary)
5
Q
What tumours are particularly metastatic to bone?
A
- Breast, lung, thyroid, prostate
6
Q
What are the most important staging systems?
A
- TNM
- Dukes’ (colorectal carcinoma)
- Ann Arbor (Hogkin’s lymphoma)
- Several site specific systems
7
Q
What is the TNM system?
A
- Tumour size/ local growth
- lymph Node metastasis
- distant Metastasis
- Combinations give rise to the 4 tier system (I-IV)
8
Q
How does TNM system work with breast cancer?
A
- T1 <2cm, T2 2-5cm, T3 >5cm, T4 any with direct extension to chest wall
- N1 1-3 ipsilateral nodes, N2 4-9 nodes, N3 >9 nodes
- M 0/1
9
Q
What is a symptoms specific to stage T4?
A
- Peau d’orange - skin of breast resembles orange peel due to local lymphoedema of skin caused by obstruction of skin lymphatics by tumour
10
Q
What is the Dukes’ staging system?
A
- Colorectal cancer - measures spread through wall and into nodes
- A = confined to bowel wall
- B - through bowel wall but not in nodes
- C - involves lymph nodes
11
Q
What is the Ann Arbor staging system?
A
- Hodgkin’s lymphoma
- Stage I one node group
- Stage II >1, same side of diaphragm
- Stage III node groups either side of diaphragm
- Stage IV non-lymphoreticular organs involved
12
Q
What are the effects of chemo on staging?
A
- May modify the STAGE of a tumour
- The prognosis is determined by the pre-treatment stage
13
Q
What are the main important factors in predicting tumour apoptosis?
A
- Classification (histological subtype)
- Grade (differentiation)
- Stage (spread)
- Molecular features (expression of receptor molecules)
- Host response to tumour (eg desmoplasia)
- Tumour effects on host (eg cachexia)
- Site of tumour
- Production of ECM (enhances spread and limits access of chemo)
14
Q
What is cancer cachexia?
A
- weakness and wasting of the body
- Worst in upper GI cancer - also seen in chronic diseases
- Unlike starvation which depletes body fat stores and tries to conserve lean body mass, in cachexia there is depletion of host reserves of fat and muscle
- Drive by cytokines including TNF and ILs, so will not respond to extra nutrition alone
