The Effect Of Your Child's Cancer On Their Brothers & Sisters

The Effect Of Your Child's Cancer On Their Brothers & Sisters

Cancer can be difficult for your child's brothers and sisters. It's common for siblings to feel guilt, rejection, fear, depression, or anxiety. Find out about how they might be affected and how you can help them.


Key points to remember about the effect of your child's cancer on their brothers and sisters

  • siblings may react to a cancer diagnosis by developing problems (academic or behavioural) or physical symptoms such as stomach pain or headaches
  • try to have open and honest conversations with your children about their brother or sister's cancer and the treatment
  • you and your extended family members can help your other children by making them feel important too

A brother and sister sitting on the grass

How can brothers and sisters be affected by their sibling's cancer?

Brothers and sisters often get information about their sick sibling second or third hand. Sometimes they hear the information from their grandparents or other relatives who are caring for them while you are at the hospital. This can lead to misunderstandings about your child's cancer and treatments.

They may react by developing academic or behavioural problems or physical symptoms such as stomach pain or headaches. They may also become overly clingy or anxious and have trouble sleeping or concentrating.

Feeling sad

Diagnosis of cancer within the whānau is a very stressful event that may change the nature of the family. Children often mirror the level of anxiety shown by other whānau members, including parents. Some children find it very difficult to talk about their feelings with whānau members for fear or worry of upsetting or burdening them. This can be a challenge also for siblings sharing with friends or extended family when everyone is asking how their sibling is doing rather than asking about them.

Feeling guilty

Some children will feel they should have been the one to get sick or that they somehow caused the illness. Sometimes they might have bad feelings about their sibling and be feel bad they are thinking that way. 

Feeling jealous and left out

A child with cancer gets a lot of attention from the whānau, community and hospital staff. You may have to leave your other children at home or with friends or relatives while you care for your sick child. Your children may see treatment days as 'special' outings for you and your child with cancer. You and extended family members can help your other children by making them feel important too. Often a little extra attention can go a long way.

Feeling angry

As treatment progresses and your child starts to look and act 'healthy', brothers and sisters can start to resent the continued attention they receive. Parents often complain of behavioural problems with siblings as treatment continues. Make sure you continue to have regular, open conversations with them. Explain just because their sibling is looking healthier - it does not necessarily mean their cancer has been cured. 

Worrying about what is happening at the hospital

Your children may worry about what is going on at the hospital instead of concentrating on their normal activities like school. On a 'bad' treatment day, your child with cancer may come home sick, and you may well be worried. If blood counts are low, there is also a chance you will have to stay with them in hospital. It is a normal emotional reaction for brothers and sisters to worry about their sibling dying.

Reassure your children that cancer does not necessarily end in death. In fact, most children with cancer have excellent recoveries. 

Worrying that other family/whanāu members might get cancer

There are still many mistaken beliefs about cancer in the community. Reassure your children that they can’t catch cancer. Let them know there is also a low likelihood that other family members will also have cancer. Cancer education that is age-appropriate can help with this. Organisations such as Child Cancer Foundation (CCF), Leukaemia & Blood Cancer (LBC), the AYA Cancer Network, and CanTeen may be able to help.

Remind them that cancer is not common in children and young people and that it is different to adult cancer.

Missing parents

Caring for your sick child can take a lot of time and energy, whether your child is at home or in hospital. Unfortunately, this means that sometimes brothers and sisters often have to 'make do' until things improve. This may mean a lack of emotional support or no one to help with things such as homework.

As childhood cancer treatment may continue for up to 2 to 3 years, it can have a major effect on your other children. Support your child to develop stronger relationships with other adults or friends during this time. This will help build resilience and strengthen their support network during this difficult time.

Worrying about you as parents

It is hard to see anyone that you love upset by something that they cannot control. Often older brothers and sisters feel the need to support parents during the 'crisis' times. They may also feel lonely because they don't want to worry you. Siblings often feel pressure to be good all the time or to take on much more household responsibility than is usual for their age. As a result of your energy being taken up by your sick child, your other children may have to rely on friends and teachers for support.

What else can I do to help my children during their sibling's cancer treatment?

Encourage them to discuss their feelings

Remind your children that whatever they are feeling - it is perfectly normal. Encourage them to discuss what they are feeling and not to bottle up their emotions.

You can ask them to write down any questions they might have and seek out answers.

If they do not feel comfortable talking with you about their feelings, you could suggest they try keeping a journal instead.

Schools and organisations such as Child Cancer Foundation, Leukaemia & Blood Cancer and CanTeen can also refer to counselling services if needed.

Get them involved

Sometimes it can be a good idea to encourage your other children to come along to doctor and hospital appointments. This way they can keep up to date with what is happening. Talk with them regularly about updates so that they are not left wondering.

Remind them they are not to blame 

It is a good idea to remind your other children they are not to blame for their sibling's cancer. It is also important to let them know that it is OK for them to have fun and play with their friends while their sibling is sick.

Let your children have time out from cancer

Having a sibling with cancer can be emotionally draining. It's important that your other children feel they can have a break from their sibling's cancer and treatment. For example, you can encourage them to spend time at a friend or neighbour's house.

Some organisations such as Child Cancer Foundation, Leukaemia & Blood Cancer and CanTeen also provide programmes for siblings of children with cancer.

Talk with their school

It might help to let your other children's school or teachers know what is going on for them so they can provide additional support. This is also helpful if they are developing behavioural or academic difficulties.

What are some good things that can come out of a sibling's cancer treatment?

While there are many challenges for siblings of cancer patients, research has shown that there can be some good things that can happen as well.1

These include:

  • an increase in sensitivity, compassion and empathy towards their sibling with cancer and others
  • an increase in family closeness
  • an increase in maturity
  • pride in their sibling's achievements
  • pride in their own achievements during times of stress
  • increased sense of independence
  • increased appreciation of life
  • maturity and resilience

See more information for educators

See more information for whānau


1Research to Practice Paper: Supporting Adolescent and young adult siblings of cancer
patients: the family context, December 2011 -  Canteen Australia.


The pages in the childhood cancer and education section of this website have been developed in collaboration with the National Child Cancer Network (NZ), and the Ministry of Education. Content has been approved by the National Child Cancer Network (NZ).

This page last reviewed 21 April 2022.

Call Healthline on 0800 611 116 any time of the day or night for free health advice when you need it