Hormones and cancer Flashcards
Non- modifiable risk of breast cancer
- Strongest = age (peak = 50-70)
- Previous breast disease (e.g. benign)
- Family history (BRCA and others)
- Hormone-related factors
Modifiable risks of Bc
High socio-economic group
(obesity, alcohol, high feat diet, smoking)
-less pregnancies
-less likley to breastfeed
What are the hormone related risks of breat cancer
Oestrogen and breast cancer
- early menarche before 12
- late menopause
- or no child or first child over 30
breast feeding reduces the risk of breast cancer
How do we test for the oestrogen receptor
-get a sample of tumor from biopsoy
-if postive 1% of cells need to express receptor
determines risk of reoccurance of if sutible for hormone therapy
oestrogen receptor positive cancer are more susceptible to hormone therapy
What does treatment depend on
how aggressive cancer is
does it have mets
Where can BC métastase
- in organs like
- skeleton bone
- liver
- lung
- brain
- skin
- ovaries
- GI system
How would you treat BC
Hormone therapy
- SERM such as Tamoxifen
- Aromatase Inhibitor (post menopausal)
- Gonadotrophin-releasing hormone analogue (pre- menopausal)
+ chemotherapy
When would you do chemotherapy to reduce metastic spread
-if tumor is poorly differenated (grade 3 or above)
-if theres lymph node involvement
-if oestrogen receptor negative
What is luminal A breast cancer
- HER2 negative
- ER (oestrogen receptor) and pgR positive
- reoccurrence is low
- few mutated genes
- responds to endocrine therapy and less to chemotherapy
How does the oestrogen receptor E2 effect cells
what binds, what happens after binding etc
Set the scene
-oestrogen is located on the nucleus surface and is associated with HSP90
- E2 (oestrodiol) passes through cell membrane
- binds onto oestrogen receptor
- causes dimmersation + phosphyrlation and lose association with HSP90
- the receptor is now on, the change in shape exposes TAF 1 band 2 reigons
- these reigons bind onto DNA
- causing the transcription of genes like insulin growth factor, progestrone receptor, TGF alpha
- these will then leave the cell, and bind back onto the cell to cause proliferation -> stimulating tumor growth
Asssuming: Co-actiavator is TAF 1+2, repressor is HSP90
IGF for example would bind onto MAP kinase pawthays, or PI3 kinase to increase expression of cyclins
Hormone therapy
SERM
what does it mean, example, risk reduction
stands for Selective oestrogen receptor modulators e.g. Tamoxifen
-reduces reoccurance by 42% with 5 years of tretment
-reduces risk of developing contralateral primary tumor
-improves survival by 22% in early cancers
Tamoxifen
dosage,use
-its SERM
-tablet 20mg daily
uses
– can be used
- neo-adjuvant -. to decrease size of tumor before surgery
- adjuvant systemic therapy: reduces metastsic spread
- can be used with chemo or alone
need to check if they have the oestrogen receptor
How do SERMs like tamoxifen work
- competitive inhibitor for oestrogen at the receptor
- it blocks the TAF-2 region on OR
- prevents recurritemnt of co-activatiors
- so no gene transcription so stops cell proliferation (cytotastic)
What is the problem with tamoxifen
- TAF 1 is still active
- long term problem
- can cause risk of endomterial cancer
What are the side effects of tamoxifen
- essitently putting person through menopause
- Menopausal symptoms such as hot flushes and sweats (40% of women)
- Fatigue (25%)
- Painful joints (25%)
- Nausea (20%)- usually only at first
Less common
- vaginal discharge/ discomfort, water retention, weight gain, headaches, depression, hair thinning
Rare
- Increased risk of deep vein thrombosis, pulmonary embolism
- Increased risk of endometrial cancer