Your cancer

Living with the disease

Hormone Therapy

What is it ?

Hormone therapy is one of several tools in the cancer treatment arsenal. Its role is essential in the treatment and prevention of relapses of hormone-sensitive cancers: in particular, cancers of the breast, uterus and prostate.


The term ‘hormone therapy’ something of a misnomer. The goal of hormone therapies is to prevent hormone stimulation of the cancer cells. In this sense, they might therefore more accurately thought of as ‘anti-hormone’ therapies. The treatments are :

Breast cancer

80% of breast cancers express estrogen and / or progesterone receptors on the surface of their cells. When these hormones attach to the surface of the tumor cells, they stimulate the proliferation of the cancer cells. To address this, there are three types of hormone therapy for breast cancer :

  • Anti-estrogens, which replace natural estrogenson the hormone receptors in tumor cells or degrade these receptors.
  • LH-RH analogues, which suppress the production of female hormones by the ovaries in pre-menopausal post-menopausal women.
  • Anti-aromatases, which prevent the production ofestrogenin post-menopausal women.

Prostate cancer

The development of prostate cancer is linked to the metabolism of androgens, in particular the binding of testosterone to the androgen receptor present in the tumor cells. All prostate cancer is initially sensitive to hormone therapy, which is referred to as sensitivity to castration. The molecules prescribed are called LH-RH agonists or LH-RH antagonists. These drugs are mainly prescribed in injectable form (subcutaneously) on a monthly, quarterly, or even semi-annual basis. This treatment can also be supplemented with tablet treatments.

When the cancer is metastatic from the onset or becomes resistant to castration, ‘next-generation hormone therapy’ can be prescribed. These are in oral form and are combined with injectable hormone therapy which are continued in parallel.

The treatment is monitored by measuring the level of testosterone in the blood in relation to PSA (prostate-specific antigen) levels.

Endometrial cancer

Like breast and prostate tissues, endometrial tissue growth is influenced by female hormones. It is these hormones that influence the menstrual cycle. When a cell cancerous, it can maintain this sensitivity to estrogen and progesterone through the presence of hormone receptors on its surface. To stop tumor growth, hormone therapy is often used.

An alternative hormone therapy, albeit less frequently used,
is the surgical removal of the ovaries (double oophorectomy) or testicles (double orchiectomy.)

Side Effects

The frequency and severity of side effects can vary greatly from patient to patient, but steps can be taken to address and minimize undesirable effects. It is therefore important to discuss your symptoms with your oncologist, as effective treatment includes awareness of side effects.

Side effects of hormone therapy include :

Osteoporosis or loss of bone density

Measurement using bone densitometry will be taken at the start and throughout the treatment.

Increase in cardiovascular risk

requiring regular monitoring and oversight, particularly in the event of pre-existing risk factors.

Weight gain

Sexual disorders

including decreased libido and erectile dysfunction.

Hot flashes


Breast pain

Decrease in size
of the penis and testicles

Risk of deep vein thrombosis (phlebitis)

in the case
of estrogen-targeting drugs


With breast cancer,hormone therapy can be used at all stages of the disease :

At the localized stage : Pprescribed after radical treatment a duration of 5 years and more in certain cases.

In the metastatic stage : alone or in combination with other systemic treatments, hormone therapy can slow down or even arrest cancer growth.

In endometrial cancer,hormone therapy is indicated in the metastatic stages. It can be prescribed alone if the cancer is in a ‘slow growth’ (indolent) state, or with fragile patients who cannot tolerate chemotherapy.

In prostate cancer, hormone therapy is a primary treatment strategy. Once started, it is typically continued indefinitely, and even in instances where resistance to castration occurs.

At the localized stagehormone therapy is prescribed in cancers where there is an intermediate or high risk of relapse. The treatment duration is based on the potential risk, and most often between six months to three years.

At the metastatic stage or in the event of resistance to secondary castration : hormonal treatment should be continued, and your oncologist may decide to include ‘new generation’ hormone therapy (tablets or +/-chemotherapy).