HP AXIS PROBLEMS

This page is part of the PanCare PLAIN summaries about late effects and recommendations for long-term follow-up care for survivors of childhood, adolescent, and young adult cancer. Click here, for more information on the PLAIN summaries.

HP axis problems

The human brain is very complex and has many functions. For example, the brain allows us to move, speak, think and feel, and controls processes that happen within the body.

The hypothalamus and pituitary are two important parts of the brain that control several processes within the body. The main function of the hypothalamus is to signal to the pituitary when to produce hormones. The hormones then travel through the bloodstream to different organs, telling them what to do.

The five main hormones produced by the pituitary are:

  • Growth hormone (GH), which is necessary for normal growth, building muscle mass and overall well being.
  • Thyroid stimulating hormone (TSH), which the thyroid needs to function normally.
  • Luteinizing hormone (LH) and follicle stimulating hormone (FSH), both important for fertility and sexual development.
  • Adrenocorticotropic hormone (ACTH), which is necessary for coping with physiological stress (for example infections, loud noises, cold/warm temperatures).

Together, the hypothalamus and pituitary are called the hypothalamic-pituitary (HP) axis. Damage to the HP axis can cause the pituitary to stop producing (enough) hormones, also called hormone deficiency. hormone deficiency may lead to HP axis problems such as impaired growth or fertility problems.

Am I at higher risk of HP axis problems?

Anyone, including people who have never had cancer treatment, may develop HP axis problems. However, there are some medical conditions and treatments that may increase the risk of having HP axis problems later in life.

The following medical conditions can increase the risk of HP axis problems:

  • A tumour near or within the HP axis
  • Hydrocephalus, when too much fluid accumulates in the brain, which may have been treated with a cerebrospinal fluid shunt

The following treatments can increase the risk of HP axis problems:

  • Radiotherapy to the HP axis or an area including the HP axis
  • Surgery near or within the HP axis

You can find out if you had any of these medical conditions or treatments by looking at your treatment summary. If you do not have a treatment summary or if you have any questions, do contact your treating hospital.

If you experience HP axis problems, it does not always mean that they are caused by cancer or its treatment. HP axis problems may have other causes.

What are the symptoms and signs of HP axis problems?

There are symptoms and signs that can tell you if you might have HP axis problems. You might not have these symptoms and signs at the moment, but it is important to be aware of them in case they may develop in the future.

One important symptom of HP axis problems is feeling very tired. However, tiredness (just like other symptoms and signs) can also have another cause.

Other symptoms and signs of HP axis problems may vary depending on the hormone which is not produced within normal values:

Not enough GH (deficiency)
  • Growth problems in children who have not completed puberty
  • Less strength, needing more rest during exercise
  • Changes in body composition, for example more fat around the waist
Not enough TSH (deficiency)
  • Growth problems in children who have not completed puberty 
  • Weight gain
  • Hair loss or thin hair
  • Dry skin
  • Constipation
  • Feeling cold easily
  • Difficulty concentrating or paying attention at school or work
Not enough LH and/or FSH (deficiency)
In children In men In women
  • No signs of puberty by the age of 13 (for girls) or 14 (for boys) or no progress of puberty for at least 6 months 

 

Signs of puberty include growth of:

– pubic and underarm hair

– breasts (in girls)

– penis and testicles (in boys)

  • Low or no sex drive
  • Difficulty with having an erection
  • Fertility problems
  • Mood changes
  • Loss of facial and/or body hair
  • Irregular or no periods
  • Fertility problems
  • Mood changes
  • Low or no sex drive
  • Hot flushes
  • Loss of pubic hair
Not enough ACTH (deficiency) 

These symptoms and signs may occur when under physical stress or having an infection

  • Low blood pressure (which can cause fainting)
  • Nausea, vomiting or abdominal pain
  • Feeling confused

If you recognise any of these symptoms or signs in yourself, please contact your general practitioner or follow-up care specialist

I am at higher risk of HP axis problems. What tests should I have and when?

If you are at higher risk of HP axis problems, it is advised to see your follow-up care specialist/
paediatric
oncologist regularly for at least 15 years after cancer diagnosis. After that time, you and your follow-up care specialist will discuss and jointly decide what the preferred follow-up care for you is (this is called shared-decision making).

The type of tests and how often you should have them depend on your age.

Before or during puberty, your follow-up care specialist may:

  • Measure growth and progress of puberty every 6 months.
  • Ask whether you have been experiencing any symptoms and/or signs of HP axis problems every year.
  • Do a physical exam every year.
  • Do a blood test to measure hormone (FT4, TSH, cortisol) in the blood every year.

After puberty, your follow-up care specialist may:

  • Ask whether you have been experiencing any symptoms and/or signs of HP axis problems every year.
  • Do a physical exam every year.
  • Do a blood test to measure hormones (in males: testosterone; in females: estradiol, FSH and LH) in the blood every year.

If you are not already under their care, it is also important to see a (
paediatric
) endocrinologist
(physician specialised in hormones) when you have had:

  • a tumour and/or surgery near or within the HP axis.
  • 30 Gy or more of radiotherapy to (an area including) the HP axis.

What happens if I have HP axis problems?

If you have HP axis problems, your follow-up care specialist will probably refer you to a:

The endocrinologist may discuss different treatment options with you, such as hormone treatment.

What else can I do?

Experiencing HP axis problems can be difficult. Talking to friends and family can be helpful as well as specialist counselling and/or contact with support groups, such as patient organisations. For more information on taking care of your mental health, please read: Mental health problems.

If you experience HP axis problems, it is very important to live a healthy lifestyle. Taking care of your mental health may be beneficial; even small changes to your lifestyle can have a positive impact on both your physical and mental health. For more information on taking up a healthier lifestyle, please read: Health promotion.

It is important that you are aware of the possibility of developing HP axis problems and that you know the symptoms and signs. If you have any further questions or the information in this brochure worries you, please contact your general practitioner or follow-up care specialist.

Where can I find more information?

You may find more information about HP axis problems online. However, it is important to be aware that this information is not always up to date or accurate.

Some sources of further information are:

  • Endocrine Society: Here you can find more information about the disruption of the endocrine system after childhood cancer or its treatment

On this website, you can also find other brochures related to this topic:

Please note

This PLAIN summary is based on the IGHG* guideline about “Hypothalamic-pituitary dysfunction” [1].

While the PanCare PLAIN information group strives to provide accurate and complete information that is up-to-date as of the date of publication, you can check with your general practitioner or follow-up care specialist if this summary reflects the most up-to-date information available and whether it is relevant for you.

Please do not rely solely on this information. It is best to also seek the advice of a qualified medical practitioner if you have questions regarding a specific medical condition, disease, diagnosis or symptom.

No warranty or representation, expressed or implied, is made concerning the accuracy, reliability, completeness, relevance, or timeliness of this information. PanCare has produced the English version and PanCare is not responsible for the translated versions of this summary.

The PanCare materials are free to use for anyone aiming to inform about late effects and long-term survivorship care. However, no financial advantage may be achieved. All communication should reference PanCare and link to the PanCare website.

*International Guideline Harmonization Group for Late Effects of Childhood Cancer

[1] Van Iersel, L. et al. (2022) Hypothalamic-Pituitary and Other Endocrine Surveillance Among Childhood Cancer Survivors. Available at: https://academic.oup.com/edrv/article/43/5/794/6432595