What should you know about oestrogen and tamoxifen?

Some breast cancer cells have receptors that respond to oestrogen. When oestrogen attaches to these receptors, it can encourage those cells to grow. Tamoxifen is an endocrine medicine that attaches to oestrogen receptors in breast tissue and reduces that signal. Its effects can differ in other tissues, so it is not simply a way to remove all oestrogen from the body.

The medicine may be prescribed after cancer treatment, alongside other care, or for risk reduction in selected people. The decision depends on receptor results, age, menopause status, other health conditions and medicines. It is taken on a schedule set by the oncology team.

Take tamoxifen exactly as prescribed and tell the team before starting any new medicine, supplement or hormonal product. Do not stop it because of a side effect without discussing an alternative plan. Keep follow-up appointments and report troublesome hot flushes, mood changes, vaginal symptoms or menstrual changes. Your clinician can review symptom relief, contraception, pregnancy plans and interactions with other medicines.

Seek urgent medical help for sudden chest pain, shortness of breath, coughing blood, one-sided leg swelling or pain, or sudden weakness or trouble speaking. These symptoms can signal a blood clot or stroke and need immediate assessment. Report unexpected vaginal bleeding promptly, particularly after menopause, so its cause can be checked.

Is my cancer oestrogen-receptor positive? What is tamoxifen intended to do in my plan? How long should I take it? Which medicines or supplements interact with it? What should I use for contraception, and which symptoms need urgent help?