Immunohistochemistry - Prognosis Flashcards
What is the main proliferation marker
Ki67
What is Ki67
(4)
Proliferation marker
Much easier than counting mitotic figures
High proliferation vs low proliferation
High proliferation = aggressive tumour
What are therapy markers
(3)
Expression of these antigens/proteins in the tumour cells is predictive of response to therapy, and/or more aggressive tumours
They look for changes in protein expression to indicate therapy
Change is the result of a mutation
Write about breast cancer therapy
(3)
Oestrogen and progesterone receptors - responsive to oestrogen blocking with Tamoxifen in 70-80% of breast tumours
Human epidermal growth factor receptor 3, Her-2-over-expression - found in 20% of cancers, may be responsive to HER2 blocking therapy (Trastuzumab immunotherapy)
What are the main breast cancer markers
Oestrogen and progesterone receptors
Her-2 over expression
How are oestrogen and progesterone receptor positive breast cancers treated
Oestrogen blocking with Tamoxifen
How are Her-2 over expression breast tumours treated
May be responsive to Her2 blocking therapy such as Trastuzumab immunotherapy
Write about colon cancer therapy markers
(3)
DNA repair proteins - loss of expression indicates genetic mutation
EGFR - high expression - may be responsive to antibody therapy
Her2 in gastric adenocarcinoma
How can EGFR positive colon cancer be treated
Antibody therapy
Write about lung cancer therapy markers
PDL1 in lung adenocarcinoma
Write about estrogen positive breast cancer
If overexpressed this means estrogen is driving the tumour
Tamoxifen can be given
Works for 70-80% of tumours
Write about Her-2 expression
Over expressed in 20% of breast cancers
Usually look for estrogen receptor first then look for Her-2 -> if you have neither than you are triple negative
Trastuzumab used to treat - majority of Her-2 can be treated with this some cannot
Write about colon therapy markers
Wide range of tumour types
Look for DNA repair proteins
These proteins are there to fix errors in DNA replication -> these take out the incorrect nucleotide and replace it
If you have a mutation in your DNA repair protein gene you will get more tumours over all but they are often found in colon but also in gynae in women (Lynch syndrome)
DNA mismatch repair proteins have been mutated -> don’t work -> they are weak points in DNA that are prone to error e.g. prone to tumours
EGFR – high expression
HER2 also seen in gastric adenocarcinomas -> only really learned this in the past 8 years – treated with Herceptin
Tend to see same mutations in different tumours -> e.g Her 2 -> could be weak points in our human DNA etc
- Lung Cancer
PDL1
What are the three types of immunohistochemistry markers for breast cancer
Diagnostic markers
Markers of myoepithelial cells - BM invasion
Prognostic and therapeutic markers
Write about breast cancer Diagnostic markers
- Cytokeratin [CAM5.2] , Epithelial Membrane antigen, Human Milk Fat globule
1 and 2 [HMFG1,2] - E-cadherin – lost or reduced in invasive lobular carcinoma
- EGFR, Cytokeratin5/6 - certain basal subtypes
Write about markers of myoepithelial cells- BM invasion of Breast Cancer
Smooth muscle actin
Calponin
p53
Write about prognostic markers of breast cancers
- Hormone receptors (oestrogen and progesterone receptors), HER 2 – human
epidermal growth factor 2, - Ki67, p53 – proliferation, prognostic
Write about p53
o P53 is the most mutated gene you will find in every tumour that exists
o P53 mutation is not good
First found as an inherited syndrome
But now this mutation has been found in many tumours outside of the inherited syndrome
How does tamoxifen work
Blocks tumour growth
Hormone therapy
Blocks eostrogen in tumour cells
Other methods of treatment not as popular
What are some other treatment regimes for breast cancer?
Aromatase inhibitors - block synthesis of oestrogen
Taxol - tree-derived antagonists of oestrogen
Write about Her2
Its an oncogene
Member of epidermal growth factor receptor (EGFR) family
Involved in cell growth and proliferation
Block with Trastuzumab monoclonal antibody therapy (Herceptin)
Found in 15-20% of invasive breast cancers and gastric adenocarcinomas
Write about Her2 amplification or overexpression in breast cancer
Its associated with increased disease recurrence and worse prognosis