Session 12: Neoplasia IV Flashcards
TNM staging system
T (how big the primary Tumour is)
-TIS carcinoma in situ, T1 <2cm, T2 2-5cm, T3 >5cm, T4 through the chest wall/skin
N (extent of regional lymph node metastasis)
- N0 no nodal, N1 Axillary, N2 mammary, N3 supraclavicular
- >this refers specifically to breast cancer
M (extent of distal metastatic spread)
M0 no metastasis, M1 presence of metastasis
General staging of maligant tumour, and definition of staging
Staging: the extent of spread of tumour
I: early local disease, T1/2, N and M0
II: advanced local disease, T3/4, N and M0
III: regional metastasis, T-, N1/2/3, M0
IV: advanced disease w/ distant metastasis, T-, N-, M1
While it is general, it is also exactly how melanoma is measured
also used to describe prostate, bladder and breast cancer
Dukes’ staging
for colorectal carcinomas
A: confined to bowel wall, not extending through muscularis propria, >90% 5 year survival
B: through bowel wall (muscularis propria/externa), 70% 5 year survival
C1/2: lymph nodes involved, 30% year survival
- C1: regional lymph nodes involved
- C2: apical node (furthest away node) involved
D: distant metastases
which stage is this?
Dukes’ stage 1: innermost lining of the bowel, slightly growing into the muscle layer
>90% 5 year survival
which stage is this?
Dukes’ stage B: grown thorugh muscle layer
70% 5 year survival
which stage is this?
Dukes’ stage C1/2 (probably C1 as it looks like the regional lymph nodes)
30% 5 year survival
which stage is this?
Dukes’ stage D: distant metastases
Ann Arbor classification
staging used in Hodgkin’s disease
I: 1 lymph node/nodal group involved
II: 2 lymph nodes/nodal groups on side of the diaphragm
III: more than 2 lymph nodes/nodal groups on both sides of the diaphragm
IV: multiple foci (bloody everywhere) - diffuse/disseminated involvement of 1/more extra-lymphatic organs eg bone marrow, lungs
Define grading and give classes
Based on the degree of differentiation of tumour cells. Attempts to judge the extent to which tumour cells resemble/fail to resemble their normal counterparts
not international classifications, somewhat subjective
Gx: grade of differentiation cannot be assessed
G1: well differentiated
G2: moderately differentiated
G3: poorly differentiated
G4: undifferentiated
Scarff-Bloom-Richardson grading
international objective grading for breast cancer
Depends on: degree of tubule formation, extent of nuclear variation and number of mitoses:
- Grade 1: 85% 10 year survival - tubules present
- Grade 2: 60% 10 year survival - no tubules, mitoses
- Grade 3: 15% 10 year survival - no tubules, mitoses, nuclear pleomorphisms
Grading of colon cancer
same classification is used for all intestinal cancers
Grade 1: grows slowly, low chance of spreading beyond bowel
Grade 2: grows moderately, medium chance
Grade 3: grows rapidly, high chance
how are prostate carcinomas graded?
Gleason grading system
Discuss the biological basis for the use of different cancer treatments
adjuvant: remove microtubules (a subclinical disease)
neo adjuvant: reduce size of primary tumour before surgical excision
Surgery: use knife to cut out tumour, can only cure the cancer when the primary tumour has not metastasised, palliative elesewhere to relieve symptoms and remove the bulk of the tumour
Radiotherapy: external radiation to tumour in small doses w/ shielding of adjacent normal tissues, causes damage to DNA of rapidly dividing cells in G2 cycle, if DNA damage (single/double strand breaks) is extensive -> apoptosis
-Sensitivity: High - lymphoma, leukaemia, seminoma - Fairly high - squamous carcinoma - Moderate - GI, breast - Low - Sarcoma
Chemotherapy: Antimetabolites mimic normal substrates involved in DNA replication eg fluorouracil
- Alkylating and platinum based drugs eg cyclophosphamide and cisplatin X-link the two strands of the DNA helix
- Antibiotics act in several different ways eg doxorubicin inhibits DNA topoisomerase needed for DNA synth., bleomycin causes double-stranded DNA breaks
- plant derived drugs include vincristine, which blocks m.tubule assembly and interferes w/ mitotic spindle formation
Hormone Therapy: Tamoxifen: competes for binding to oestrogen receptor - selective oestrogen receptor modulators (SERMs), 50-80% of breast cancers express oestrogen receptors
- Herceptin: a humanised monoconal AB that binds to HER-2 (human epidermal GF receptor)-2 which is overexpressed in 20-30% of breast carcinomas
- > this is an example of oncogene therapy, it is non toxic and only targets molecules in cancer cells
surgical treatment of cancers
use knife to cut out tumour, can only cure the cancer when the primary tumour has not metastasised, palliative elesewhere to relieve symptoms and remove the bulk of the tumour
radiotherapy treatment of cancers
external radiation to tumour in small doses w/ shielding of adjacent normal tissues, causes damage to DNA of rapidly dividing cells in G2 cycle, if DNA damage (single/double strand breaks) is extensive -> apoptosis
-Sensitivity: High - lymphoma, leukaemia, seminoma - Fairly high - squamous carcinoma - Moderate - GI, breast - Low - Sarcoma
