Oestrogen Receptor-positive Breast Cancer
Oestrogen receptor-positive breast cancer is breast cancer whose cells express oestrogen receptors and can use hormonal signalling for growth.
Key takeaways
- Pathology confirms receptor status; ER positivity does not describe stage, HER2 status or recurrence risk by itself.
- Endocrine treatment lowers recurrence or controls advanced disease, with drug choice strongly influenced by menopausal status.
- Clot, uterine, bone, joint and cardiovascular risks differ between tamoxifen, aromatase inhibitors and ovarian suppression.
The listings below are not a treatment plan; oncology should define stage, benefit, duration and monitoring.
Choosing endocrine treatment
Tamoxifen blocks oestrogen receptors and can be used before or after menopause, while aromatase inhibitors are mainly used after menopause or with ovarian suppression. Adjuvant duration depends on recurrence risk and tolerability. Advanced disease may combine endocrine treatment with targeted agents.
Monitoring treatment effects
Tamoxifen increases clot risk and can affect the endometrium; unexpected bleeding needs assessment. Aromatase inhibitors accelerate bone loss and can cause joint symptoms, so bone density and fracture prevention matter. Adherence review should address adverse effects rather than silent discontinuation.
When to seek urgent care
Seek urgent care for chest pain, sudden breathlessness, coughing blood, a painful swollen leg, new neurological symptoms, heavy bleeding or fever during systemic cancer treatment.