Endocrine Therapy

Endocrine Therapy (Hormone Blockers)

Some types of breast cancers are sensitive to the female hormones oestrogen and progesterone as we explained in the “Different types of Breast Cancer” section. The breast cancer cells have receptors (proteins) that attach to oestrogen and progesterone, which help them grow. Treatments that stop these hormones from attaching to the cancer receptors or lowering the oestrogen levels so much that they can’t attach, are called hormone blocking or endocrine therapy and are a very important part of the treatment of these cancers.

You can think of the hormones as “food” for cancers and by taking away the food with the hormone blockers, we are starving the cancer cells and therefore stopping its growth. Hormone blockers can reach cancer cells almost anywhere in the body and not just in the breast which is what makes it so powerful in helping to treat the cancer and preventing it from coming back or spreading.

When is Endocrine Therapy used?

Hormone blockers are often used both before and after surgery to help reduce the risk of the cancer coming back. Patients are encouraged to use these tablets every day for at least 5 years when the risk for recurrence or spread is the highest. Hormone blockers can also be used to treat cancer that has come back after treatment or that has spread to other parts of the body.

Two types of Endocrine Therapies:

#1 TABLETS THAT BLOCK THE OESTROGEN RECEPTORS

• Tamoxifne
• Fulvestrant (Faslodex)

These tablets are usually prescribed to younger patients that are not in menopause (still getting peroids) yet and have higher levels of circulating oestrogen. By blocking the receptors we can starve the cancer cells even though there is oestrogen circulating in the body. Occasionally we need to try and suppress the ovaries to make less oestrogen (with an injection or by removing them) in order to make these tablets work even better in women with very high oestrogen levels.

#2 TABLETS THAT LOWER OESTROGEN LEVELS

• Aromatase Inhibitors (AI) like Arimidex

These tablets are usually prescribed to patients who are already in menopause (stopped getting peroids). We still need to lower the levels of estrogen because oestrogen is not only produced in the ovaries but also elsewhere in the body like fat cells.

What are the Side-effects?

The side-effects are very similar to the symptoms that women experience when going through menopause and can vary from patient to patient. Some patients (especially those already in menopause) experience very little to no side effects and for others the adjustment can be quiet challenging. All these side effects are manageable and should not prevent you from taking this very important part of your treatment.

Are there risks in taking Endocrine Therapy?

Tablets that lower the level of oestrogen (aromatase inhibitors) have very little risk except for osteoporosis (thinning of the bones) for which you will be prescribed calcium and vitamin D tablets to help keep your bones strong. Tablets that blocks the oestrogen (Tamoxifen) have some risk but these occur rarely, but could increase risk of:

• Endometrial hyperplasia (thickening of the wall of the womb) – visit your gynae clinic once a year and report any abnormal vaginal bleeding
• Polyp (growths) in the womb. Visit your gynae clinic once a year and report any abnormal vaginal bleeding.
• Endometrial (womb) cancer (rare). Visit your gynae clinic once a year and report any abnormal vaginal bleeding or lower abdominal pain.
• Deep venous thrombosis (blood clot in leg). If you experience sudden sharp and severe pain in your lower leg (calve muscle), report to your nearest emergency unit immediately.
• Pulmonary thromboembolism (blood clot in lungs). If you experience sudden shortness of breath, report to your nearest emergency unit immediately.

What can I do to limit by side-effects?

Don’t despair and don’t give up. Most importantly, do not stop your treatment, but rather discuss it with your doctor.

There are several things that you can do to take control of your symptoms and overall well-being (also see our section on Deliberate Living at the end of the book as many of these principles will aid you greatly in managing your symptoms).

• EXERCISE has been shown in many studies to improve joint and muscle aches, increase energy levels and improve mood. You don’t have to run a marathon but regular brisk walks, stretching and some simple strength exercises will make a big difference.
• SLEEP will improve your mood, energy levels and ability to cope with side-effects
• EATING a diet rich in fibre, healthy grains and good fats will help manage your weight, joint health and mood
• COOL yourself by using a fan, wearing light clothing and drinking plenty of water. You can also use cold compresses like an ice pack) on your wrists, feet and around your neck as cooling these points have a cooling effect on the body
• AVOID any “natural” menopause medication as these still contain oestrogen (even if it comes from plants) that is bad for your cancer
• MEDICATION that your doctor can prescribe to help you manage your side effects include:
  • Venlor/Venlafaxine (an anti-depressant that can help with hot flushes and a low mood
  • Clonidine (that can help with hot flushes)
  • An anti-inflammatory that can help with joint pain
  • Amitriptyline that can help with sleep, mood and pain
  • Supplements like vitamin D, vitamin E, Omega 3 and 6, Calcium and magnesium that can help with your bone strength as well as muscle aches and pains
• STAY POSITIVE as a positive mindset is the most powerful tool in the world to not only survive but thrive!
• SHARE your challenges with fellow patients, friends, or family, and don’t ever be ashamed to ask for help.