Feelings and fears
If your brother or sister has cancer, you're probably feeling sad and worried because you love them and you want them to get better. You might find it a bit frightening to visit the hospital, or see your brother or sister upset, in pain or acting differently. You might also feel lonely without your brother or sister to play with as usual, and this might make you feel guilty because you are well and want to play, and your brother or sister is sick. You might be jealous when they get all the attention and you feel left out.
Find someone to talk to
All these feelings are normal, and it's best to talk to your mum or dad whenever you have any of these feelings. They will be able to explain what's happening to your brother or sister. Other people you can talk to include your grandparents, other relatives, other adults in your community who you trust, your friends, your teachers, school counsellors and hospital social workers.
Be sure to ask your mum or dad, or other trusted adults, things like what your brother's or sister’s illness is; what all the doctors’ visits, tests and treatments are for; and what they want you to do to help. If you're feeling sad, don’t pretend to be OK so that you don’t upset mum or dad. They love you and will want to do everything they can to look after you as well as your brother or sister.
Don't worry you can't catch cancer
There's no need to be worried that you'll get cancer as well. Cancer is very rare, and it's not common for more than one child in a family to get cancer. You can’t catch cancer from your brother or sister, like a cold or chickenpox, so you don’t need to worry about being with them, and you can give them lots of hugs and kisses.
Tell your friends and family how you feel, don't pretend to be OK when you're not
Remember that other people won't know how you're feeling. It's not happening to them, so they might not fully understand what it's like for you. They may be too scared to ask questions or not know the right questions to ask. So you need to tell your friends how you feel and how you would like them to act when they're with you. Don’t pretend to be OK when you're not, or let other people play down your feelings. What you're going through is very difficult, and it's best for everyone to be honest about it.
Being a transplant donor
If your brother or sister has leukaemia or some other types of cancer, you might be asked to help with their treatment by donating some of your stem cells. This is also called a bone marrow transplant. Your family, and your brother's or sister's doctor will explain all this to you.
Stem cells are special kinds of cells that are found in your bone marrow (the spongy stuff inside your bones). Stem cells can make new blood cells.
Some types of cancer happen because the person's blood cells don't work the way they should. Doctors can replace the bad blood cells with new stem cells that can make healthy new blood cells, and this can help to treat the cancer.
For a transplant to work, your stem cells have to be very, very similar to your brother's or sister's stem cells. If you have the same mum and dad, there is a better chance that your cell types will match. You'll have to have a test to see if your stem cells are the right type to transplant to your brother or sister.
If your cells aren't the right type, don't feel guilty – there's nothing that you or anyone could have done about it. It’s a bit like if you have brown hair and your brother has blond hair – you were just born that way.
See CanTeen's free online books for siblings. CanTeen helps young people (aged 12-24) cope with their own or cancer in their family. Through CanTeen, young people can access counselling, information and other support as well as connect with others going through the same thing. For young people with cancer, the Youth Cancer Services provide specialist, age-specific treatment and support.
Siblings Australia has more information about being a brother or sister to someone who's sick, including stories from other kids about how they deal with it.