15. Breast Cancer Flashcards
What sort of cancer are most breast tumours?
Carcinomas (arising from ductile tissue)
Recall the structure of the epithelium in normal breast
2 layers - inner epithelium and myoepithelium (contractile)
Recall 2 types of carcinoma that can arise from an in situ carcinoma of the breast
Lobular Medullary
Which of the 2 types of breast carcinoma are better differentiated?
Lobular
What % of breast cancers are ER+?
80
What is the most common form of ER+ breast cancer?
Infiltrating ductal carcinoma
Recall 3 factors that influence lifetime oestrogen exposure
- Menarche 2. Timing of first pregnancy 3. Contraceptive pill/ HRT
Recall 4 important genes that are regulated by oestrogen
Progesterone receptor TGF-alpha c-Myc Cyclin D1
Recall the 3 general approaches to medical breast cancer treatment
- Ovarian ablation 2. Enzyme inhibition 3. Oestrogen inhibition
Recall the 3 options for ovarian ablation
- Surgical oophrectomy 2. Ovarian irradiation 3. LHRH agonist
Which of the options for ovarian ablation is most useful in pre-menopausal women?
LHRH agonist - no risk of fertility loss
How is LH suppressed by LHRH agonist treatment?
Overload of LH = down-regulation of receptors –> LH suppression
Recall the 2 approaches of oestrogen inhibition in breast cancer therapy
Aromatase inhibitors Antioestrogens
What are the 2 classes of aromatase inhibitor?
Suicide inhibitors Competitive inhibitors
Give an example of a suicide-inhibitor aromatase inhibitor
Exemestane
Recall the MOA of exemestane
Alkylates active site of aromatase inhibitor to irreversible inhibit it
What is the most-commonly prescribed aromatase inhibitor drug?
Anastrazole (reversible)
Give an example of a reversible aromatase inhibitor?
Anastrazole
What sort of drug is tamoxifen an what is the effect of tamoxifen on the cell?
SERM Halts cell at G1
In what tissues does tamoxifen have an oestrogenic and protective effect?
Bone CVS
What is the first line treatment for PR+ breast cancers?
Progestins
