Side Effects Of Hormone Therapy

Introduction

Hormone therapy is a treatment that removes, blocks or adds specific hormones to the body. It is also called endocrine or anti-hormone therapy. 

Hormone therapy is used for various medical conditions, with the available treatment options varying based on your condition. Some cancer treatments use the body’s natural hormones to stimulate growth. This is different from menopause hormone therapy (MHT) or hormone replacement therapy (HRT).

Hormone therapy is considered a systemic treatment because both the drugs and hormones involved circulate through the body in the bloodstream. This makes hormone therapy different from treatments that only target certain parts of the body, like most types of surgery and radiation therapy. These are called local treatments because they affect one part of the body.

Types of hormone therapy

Hormone therapy drugs travel through the body to find their target hormones. Each hormone therapy works in its own specific way. They can:

• Stop the body from making specific hormones 
• Block hormones from attaching to cancer cells
• Alter the hormone so it does not work as it should

Hormone therapy for cancer treatment

Hormone therapy is used to treat breast and prostate cancers, which both use our hormones to grow. Hormone therapy is often used along with cancer treatments. The type of treatment selected by your doctor will depend on the type of cancer you have, how much it has spread, whether it uses hormones to grow, and any other health problems you have. 

Hormone therapies used to treat breast cancer include: 

• Aromatase inhibitors, such as anastrozole and letrozole
• Selective oestrogen modulators (SERMs), such as tamoxifen and raloxifene 
• Surgeries to remove the ovaries 
• Luteinising hormone-releasing hormone (LHRH) agonists, such as goserelin. These drugs switch off oestrogen production in women by the ovaries

Hormone therapies used to treat prostate cancer include:

• Antiandrogens such as apalutamide, bicalutamide, and flutamide (also called androgen deprivation therapy or ADT)
• Luteinising hormone-releasing hormone (LHRH) agonists, such as goserelin 
• Surgery to remove the testicles 

Hormone therapies used to treat endometrial cancer include:

• Progestogen, such as medroxyprogesterone acetate or megestrol acetate 
• Selective oestrogen modulators (SERMs), such as tamoxifen and raloxifene
• Luteinising hormone-releasing hormone (LHRH) agonists, such as goserelin 

When hormone therapy is used with other treatments, hormone therapy can be:

• Neoadjuvant therapy: used to make a tumour smaller before surgery or radiation therapy 
• Adjuvant therapy: used to decrease the risk of cancer coming back after the primary treatment
• Used to destroy cancer cells that have returned to the body after the treatments and stop them from spreading to other parts of the body

Hormone replacement therapy (HRT)

Hormone replacement therapy, also called menopausal therapy, is a treatment used to relieve the symptoms of menopause. Hormone replacement therapy stimulates the production of oestrogen and progesterone, which are female sex hormones that the body stops making during menopause. 

Menopause is when your regular menstrual periods stop due to low levels of hormones. It generally affects people assigned female at birth (AFAB) between the ages of 45 and 55, but it happens earlier in some people. Oestrogen and progesterone have essential roles in the menstrual cycle, ovulation, and pregnancy.

These hormones also keep bones healthy. As such, the loss of these hormones can affect your body in various ways. To replace these hormones, a combination of oestrogen and progesterone treatment can be conducted.

There are many types of HRT which use different hormones and delivery methods, such as skin patches, gel and injections. Your healthcare provider will suggest which approach is best for you depending on your medical conditions and medical history.

Anti-hormone therapy

Anti-hormone therapy is a type of hormone therapy that suppresses selected types of hormones and their effects. It is used in the treatment of certain cancers, as some hormones stimulate the growth of tumours.

Examples of anti-hormone therapy include:

• Anti-androgen: a type of medication that binds with androgen receptors on prostate cancer cells to inhibit their growth
• Anti-oestrogen: a type of hormone therapy that aims to slow or stop the growth of hormone-sensitive tumours. It is used to treat all stages of hormone receptors-positive breast cancer

Hormone therapy for gender transition 

When a person experiences conflicts between their biological gender and gender identity, it is called gender dysphoria. Hormone therapy is one of several available treatments for gender dysphoria, and it helps people to live more comfortably.

The treatment involves administering sex hormones and other hormonal medications. The medicines used for feminising hormone therapy include oestrogens, antiandrogens, progesterone and gonadotropin-releasing hormone modulators. For masculinising hormone therapy, common medications include androgens (testosterone), progestins, GnRH agonists and antagonists, and 5α-reductase inhibitors. 

Hormone therapy can help reduce the stress and discomfort associated with gender dysphoria. It can be offered to young people and adults, but there are strict criteria to be met beforehand. Puberty blockers pause the physical changes associated with puberty, such as the development of breast or facial hair.

In some cases, these hormones can cause irreversible changes, such as breast development and breaking or deepening of the voice. Therefore, careful consideration is crucial before receiving the treatment.

Common side effects of hormone therapy

Because hormone therapy blocks the ability of the body to stimulate hormones or interfere with how hormones behave, it can cause unwanted side effects. 

Each patient’s side effects can be different, depending on the type of hormone therapy and other factors. It is important to know the possible side effects when making treatment decisions. It is important to balance the benefits and risks of any treatment. 

Some common side effects for individuals assigned male at birth (AMAB) receiving hormone therapy for prostate cancer treatment include:

• Hot flashes 
• Decrease sexual desire 
• Weakened structure 
• Erectile dysfunction 
• Memory problem 
• Weight gain

Individuals assigned female at birth receiving hormone therapy for breast cancer or endometrial cancer may have the following side effects:

• Hot flashes 
• Vaginal dryness 
• Mood changes 
• Loss of interest in sex
• Fatigue 
• Nausea 
• Bone loss and high risks for fractures

Severity and management of side effects

The severity and management of side effects depend on the type of hormone therapy used and the medical condition. It can also vary from person to person and how long they are receiving the treatment. Some side effects are short-term, and some can last until the treatment finishes.

There are some ways that can help you manage your side effects and make hormone therapy easier, including:

• Eating a healthy, balanced diet 
• Engaging in gentle exercises
• Avoid smoking 
• Reducing alcohol
• Getting enough rest

Exercise not only has physical and mental health benefits but can help with treatment side effects, such as fatigue, sleep deprivation and anxiety. Getting emotional and social support during the treatment can also help manage the side effects.

Long-term effects and risks

Hormone therapy can cause a range of side effects, such as: 

Bone health and osteoporosis

Some hormone therapies, such as aromatase inhibitors, can cause thinning of bones.¹ For example, tamoxifen can cause bone thinning in premenopausal individuals AFAB but not in postmenopausal women. In the latter group, tamoxifen actually helps maintain bone strength.^2,3

Weight-bearing exercises can help build up the bones and protect them. This includes any exercise where you are carrying your own weight, such as walking, running or cycling. Swimming, on the other hand, is not a weight-bearing exercise; however, it is still beneficial for your muscular and cardiovascular health. 

Bone thinning can lead to osteoporosis (weakened bones) and bone fractures if the problem exists for a few years. You may need medical treatment to be strengthen your bones.

Cardiovascular risks

Hormone replacement therapy (HRT) can increase the risk of cardiovascular disease and stroke for people AFAB and over 60 years of age. This is more likely if they started HRT late into the menopause and used combined HRT. Your risk of cardiovascular disease and stroke also depends on the dose of HRT you took and how it was administered. The risks are lower if the dose is smaller or an HRT patch or gel is used.⁴

Blood clots 

HRT can increase the risk of thrombosis (blood clotting). However, this can be influenced by many other factors, such as your smoking history, weight, and age. Using a skin patch or gel can reduce the risks of HRT.⁵

FAQ's 

How much does hormone therapy cost?

The cost of hormone therapy depends on:

• The type of hormone therapy 
• The length and frequency of the treatment 
• Your health insurance policies 

It is advisable to speak to your healthcare provider about all of your available treatment options.

How is hormone therapy given?

• Pills 
• Intramuscular injection
• Surgery to remove organs that produce hormones. For example, people AFAB may have their ovaries removed, whilst people AMAB may have their testicles removed

How do hormones affect your diet?

Some cancer treatments can cause weight gain, such as prostate cancer. Speak to your healthcare provider or dietitian if weight gain becomes a problem.

Summary

Hormone therapy is used to increase or decrease certain hormones in the body. Certain medical conditions require hormone therapy to improve the symptoms or prevent disease recurrence. However, in many cases, the benefits of hormone therapy outweigh the side effects. 

Hormone therapy may also be used to help or prevent cancer treatment side effects. Managing cancer and its side effects is an important part of patient care and treatment. Speak to your healthcare provider to understand the side effects of hormone therapy before starting the therapy.