What is Hormone Therapy?

23 Aug 2021

What is Hormone Therapy? 

Hormone therapy is an oral medication, taken daily for at least five years after the completion of other breast cancer treatments. These drugs are a prophylactic treatment for those diagnosed with hormone receptor positive breast cancer.

Two-thirds of most breast cancers diagnosed are hormone positive, this means that the cancer cells require female hormones (oestrogen and/or progesterone) to grow and replicate. Hormone therapy will be prescribed to most women with hormone receptor positive breast cancer.

Tamoxifen is the most well-known hormone therapy drug and is used to treat both pre and post-menopausal women. Femara, Arimidex and Aromasin, and the generic brands of each, are also hormone therapies however they are only suitable for women that are post-menopausal.

How does Hormone Therapy Work? 

An important component of cancer treatment is the reduction of the risk of cancer spreading to other parts of the body or of a new breast cancer growing in the same or other breast. Hormone therapy does this by stopping the female hormones from fuelling any breast cancer cells.

Tamoxifen does this by selectively blocking oestrogen’s action on breast cells and is called a SERM.  Femara, Arimidex and Armoasin are Aromatase Inhibitor’s which shut down the production of oestrogen in post menopausal women.

Hormone Therapy Side Effects

Both therapies can have similar side effects, some of these can be:

  • Menopausal symptoms such as hot flushes, night sweats, heart palpitations
  • Anxiety
  • Sleep disturbance
  • Fatigue

Aromatase Inhibitors can also cause:

  • Bone density loss
  • Joint stiffness and pain
  • Vaginal dryness

Your doctor and medical team will work with you to monitor and manage any side effects that you experience.