The treatment of Cushing's syndrome will depend on the cause of the high levels of cortisol. If you have iatrogenic Cushing’s syndrome that's caused by taking corticosteroids, you'll need to gradually reduce then stop your dose of corticosteroid medication.
If you have endogenous Cushing’s syndrome that's caused by tumours, you have the following treatment options:
Corticosteroids
If you've only been taking corticosteroids for a few days, it may be possible to safely stop the dose straight away. However, most people with Cushing’s syndrome have been taking high-dose corticosteroids for some time so it's not safe to stop the dose.
This is because if you've been taking corticosteroids for a long time, your body may stop producing natural steroids. So if you suddenly stop taking your medication you may have symptoms such as:
- fatigue
- weight loss
- feeling sick
- dizziness
- being sick
- diarrhoea
Another factor is the condition for which you've been prescribed your medication in the first place. In some cases, there may be an effective non-steroidal treatment. However, if this is not the case you may be advised to continue taking corticosteroids until the symptoms of that condition are under control.
There's no ‘one size fits all’ plan for withdrawing treatment with corticosteroids. However, the following steps are recommended for most people:
- Reduce the dosage from a high dose to a medium dose or a medium-high dose.
- Then switch to an even lower dose or, alternatively, only take your medication every other day.
- Then, after a number of weeks or months, have a blood test to see whether your body is now producing natural steroids.
If, after the steps described above, your body is producing natural steroids, it should be safe to withdraw treatment. If your body isn't producing natural steroids, continuing a low-dose treatment may be recommended for another four to six weeks before being tested again.
The time that it takes for someone to safely withdraw from taking corticosteroids can range from a few months to more than a year. You may need additional treatment during this time to compensate for some of the symptoms of Cushing’s syndrome, such as medication to lower your blood pressure.
Cortisol-inhibiting medications
Cortisol-inhibiting medications are designed to block the adverse effects of cortisol. They tend to be used only on a short-term basis as a preparation for surgery. Sometimes they're used for a short time after surgery or radiotherapy in order to make these types of treatment more effective.
Occasionally, however, cortisol-inhibiting drugs are used on a long-term basis in people who are unwilling or unable to have surgery. Ketoconazole and metyrapone are two widely used cortisol-inhibiting drugs.
You should be aware that ketoconazole is not licensed for the treatment of Cushing’s syndrome. This mean that the manufactures designed and tested the medication to treat another condition – fungal infection – but it was subsequent found to also be useful in the treatment of Cushing’s syndrome.
But due to this fact there have been no large scale safety trials of ketoconazole in people with Cushing’s syndrome. The doctor in charge of your care will be able to provide more information about this.
Read more about how medicines are licensed and what medications are used to treat Cushing's syndrome.
Surgery
Surgery may be needed to remove or destroy a tumour in the pituitary gland or the adrenal gland.
Removing a tumour from the lungs is much more challenging and may not be possible.
Pituitary surgery
Under general anaesthetic, the surgeon will remove your pituitary tumour through your nostril or an opening that's made behind your upper lip, just above your front teeth.
This approach allows the surgeon to reach your pituitary gland without having to operate on the main part of your head. This reduces the risk of complications, such as infection.
This type of surgery has a good track record of success. Around four out of five people’s symptoms are completely cured.
Adrenal gland surgery
In most cases, only one of your adrenal glands will need to be removed. This is usually done using laparoscopic (keyhole) surgery, in which the surgeon makes a small incision in your abdomen and passes tiny instruments through the incision to remove the adrenal gland. The advantage of this approach is that you'll feel less pain after surgery and have minimal scarring.
This type of surgery also has a good record of success. Two out of three people’s symptoms are completely cured.
The lungs
In many cases, the tumour is located deep inside the lung so it's not possible to safely remove or destroy it without seriously damaging the lungs. An alternative approach is to use cortisol-inhibiting medication or completely remove the adrenal glands, which will stop the production of cortisol.
Radiotherapy
If pituitary surgery proves unsuccessful, radiotherapy is an additional treatment where high-energy waves can be used to shrink the tumour.
A type of radiotherapy known as stereotactic radiosurgery (SRS) is increasingly being used to treat pituitary tumours. SRS involves using a series of movable frames to hold your head in a precise location. Then a computer sends energy rays to the exact location of the pituitary tumour.
This new approach minimises the chances of accidental damage to other parts of the brain. It usually takes just one session to perform.
SRS is only available at a number of specialised centres so it's likely that you'll have to travel from your home to receive treatment. There may also be a waiting list until treatment becomes available. The results of SRS are good, with 3 out of 4 people experiencing a complete cure from their symptoms.
Treatment failure
If pituitary surgery, adrenal gland surgery and/or radiotherapy fail to achieve a cure, it may be recommended that both of your adrenal glands be surgically removed so that they can no longer produce cortisol.
This treatment option may be highly recommended if your symptoms of Cushing’s syndrome put your long-term health at risk, such as poorly controlled high blood pressure.
Complications of surgery
Loss of hormonal function
The surgeon will try to save as much pituitary or adrenal gland as possible to preserve their normal functions of producing hormones. However, in some cases, this is not possible, particularly if a tumour is quite large.
People who have had their entire adrenal gland removed will lose normal hormonal function. Those undergoing radiotherapy have a significant risk of losing normal hormonal function.
If you lose normal hormonal function, you'll have to take synthetic versions of the hormones that the affected glands used to make. This is sometimes referred to as hydrocortisone replacement therapy (not to be confused with hormone replacement therapy, which is used to treat the symptoms of the menopause).
Hydrocortisone comes in tablet form. Most people need to take one or two tablets a day. In some cases, your glands may recover normal function after a few months, so treatment can be stopped. Other people may need to take hydrocortisone for the rest of their life.
Most people tolerate hydrocortisone well, but it can take some time to work out what's the most appropriate dose for you. During this time you may have some Cushing syndrome-like side effects, such as weight gain and thinning of your skin.
Nelson’s syndrome
Nelson’s syndrome is a relatively common complication that occurs in people who have had both of their adrenal glands removed because they were unresponsive to surgery or radiotherapy.
Nelson’s syndrome is where a rapidly growing tumour develops inside your pituitary gland. The symptoms include:
- darkening of your skin
- headaches
- vision disturbances, such as partial loss of vision or double vision
Nelson’s syndrome is poorly understood, both in terms of what causes it and how common it is. One study carried out several years ago found that one in four people who had both adrenal glands removed went on to develop Nelson’s syndrome. However, the figure is likely to be lower today due to improvements in the treatment of Cushing’s syndrome.
The treatment recommended for Nelson’s syndrome is to surgically remove the tumour. This may be followed by an additional course of radiotherapy as discussed above.
