Breast Cancer Flashcards
How is breast cancer classified?
Based on presence of oestrogen receptors (ER), progesterone receptors (PR) and HER-2 receptors.
What are the 4 subtypes of breast cancer?
Luminal A: HR positive, HER-2 negative
Luminal B: HR positive, HER-2 positive
HER-2 enriched: HR negative, HER-2 positive
Triple negative: HR negative, HER-2 negative
What is HER-2?
HER-2 is a protooncogene that controls cell division. Overexpression of the HER-2 gene results in the formation of breast cancer.
What are the risk factors for developing breast cancer?
Family history of breast cancer in a first-degree relative (mother, sister)
Increased oestrogen exposure (early age at menarche, nulliparity, older age of first pregnancy)
Lifestyle (alcohol intake, obesity, cigarette smoking)
What are the types of surgical treatment of breast cancer and when are they indicated?
Lumpectomy and masectomy. First-line treatment for breast cancer, should be initiated first before other treatments.
What is the place of radiation therapy in breast cancer treatment?
Used following surgery to ensure complete eradication of cancerous cells.
What kinds of endocrine therapy are available?
Aromatase inhibitors, SERMs, ovarian suppression, fulvestrant, CDK4/6 inhibitors.
Aromatase inhibitors examples and MOA?
Anastrozole, letrozole, exemestane
Inhibit the aromatase enzyme which is involved in the production of oestrogen from androgens in peripheral sites.
SERMs examples and MOA?
Tamoxifen
Blocks the oestrogen receptor on breast cancer tumours to prevent oestrogen-dependent growth and proliferation.
What kinds of ovarian suppression therapies exist?
Oophrectomy and GnRH agonists
GnRH agonist examples and MOA?
Agonist at GnRh receptor which inhibits the production of LH and FSH resulting in the decreased production of oestrogen.
Which endocrine therapies are recommended for post-menopausal women and why?
In post-menopausal women, the ovaries stop producing oestrogen. Thus only peripherally produced oestrogen needs to be inhibited. As such, aromatase inhibitors are preferred.
Which endocrine therapies are recommended for pre-menopausal women and why?
In pre-menopausal women the ovaries are still producing oestrogen, which must be prevented. This can be done either by using ovarian suppression therapy (oophrectomy, GnRH analogues) or Tamoxifen.
What is the recommended treatment of HER-2 positive breast cancer? MOA?
Trastuzumab (Herceptin). Monoclonal antibody which is an agonist of the HER-2 receptor to inhibit action of growth signals.
What is the difference between trastuzumab and trastuzumab emtansine?
Trastuzumab emtasine is trastuzumab covalently linked with a DM-1 microtubule inhibitor. The microtubule inhibitor is internalised into cancer cells causing cell-specific targeted cytotoxic therapy.
