What Causes Cancer in Children?
The blueprint telling every cell in our bodies what to do is in our genes. Most cancers develop after a child is conceived because of changes in one or more genes in a cell (such as an eye cell, kidney cell, etc.). These changes turn it from a normal cell into a cancerous cell. Such “genetic mutations” do not get passed on to their children.
Other genetic mutations are inherited. The mutation is in the sperm or egg cell, which means it affects all of the cells in the child’s body. It can be passed from generation to generation within a family, from parent to child. Inheriting a genetic mutation that raises the risk of cancer makes a person “predisposed” to that cancer. It is important to know, however, that a person who is more likely to get certain types of cancer may not actually develop them.
Memorial Sloan Kettering has led the way in understanding cancer genetics since the field began decades ago. Our doctors and scientists have made important discoveries about screening, treatment, and ways to reduce the risk of hereditary cancers. The experts in the MSK Kids Clinical Genetics Service and Pediatric Cancer Predisposition Screening Program can help you and your family understand how genetics plays a role in your child’s illness. You can also learn if any genetic mutations may affect your other family members. From your first appointment to follow-up care, we are here every step of the way to guide and support you.
How We Use the Results of Genetic Testing
We know more today than ever before about the genes that are related to childhood cancers. Genetic testing for cancer can be done in two ways: testing cancer cells themselves or testing healthy cells, usually from the blood. Testing cancer cells shows which mutations are present in a cancer, while testing healthy cells may show if your child has a predisposition that could explain why the cancer developed.
Our experts will work with your family and the rest of your child’s cancer care team to determine the most helpful genetic testing for your child. The results of this testing can provide important information that may:
- Confirm your child’s diagnosis. Some predisposing mutations are associated with specific tumor types. Knowing exactly what your child’s cancer is helps MSK care teams recommend the best treatment plan.
- Identify cancer targets. You may have heard about the anticancer medications called targeted therapies. These drugs work by blocking certain abnormal proteins involved in cancer’s growth. These abnormal proteins are made as a result of genetic mutations. Some children’s cancers are caused by genetic mutations that produce proteins for which there are targeted therapies. If we find one of these genetic mutations, we will work with your child’s cancer care team to help determine if certain therapies may be useful. We may also learn which treatments to avoid because they will not be effective.
- Help plan future cancer screening for your child. If genetic testing shows that your child has a predisposition to certain types of cancer, they may benefit from screening for these types of cancer. Screening may help detect cancers early, when they are easier to treat. Sometimes there may be ways to lower the risk of cancer developing. For example, some children who have a predisposition to thyroid cancer may have surgery to remove the thyroid. This can prevent thyroid cancer from developing.
- Prompt genetic testing and cancer screening in family members. If testing shows that your child has a mutation that can be inherited, then you and your other family members may also have it. We’ll talk with you about the option for you and your relatives to have genetic testing and what can be done if the mutation is present.
- Help with planning your family. When some parents learn that their child has a genetic mutation that increases cancer risk, they ask if there is a chance they could conceive other children with this mutation. We understand your concerns. We can provide information and guidance that can help you make important decisions.
Our Clinical Genetics Team Is Here for You
Understanding cancer genetics can be overwhelming. We get that. That’s why we’ve assembled a team of experts to give you the knowledge and comfort you need to make healthcare decisions. Our team includes:
- Genetic counselors. These healthcare professionals have advanced training to assess your child’s diagnosis and family history. They order, analyze, and discuss genetic testing results with you. We offer genetic testing to almost every young MSK patient and their family. Your genetic counselor will explain the results of your child’s testing and help you make informed choices about your decisions related to genetic testing.
- Geneticists. These doctors have advanced training in clinical genetics. They work closely with your genetic counselor and analyze genetic testing results to provide information that is useful for making healthcare decisions. Our team is led by Michael Walsh, who is both a geneticist and pediatric oncologist. Dr. Walsh is an internationally known expert in pediatric cancer genetics and screening for children and families with genetic mutations related to cancer.
Do I Have to Get Tested?
No. Genetic information is very personal. We know that it can be scary to learn that you or other people in your family have a genetic mutation that increases cancer risk. We also understand that everyone has different levels of comfort receiving this kind of information. That’s why we meet with you to better understand your level of comfort and to explain the genetic testing process so you can make an informed decision about whether to be tested. And once you make that decision, we respect it.
Screening for Cancer and Reducing Your Risk
If you learn through genetic testing that your family has an inherited risk of cancer, Dr. Walsh and the MSK Kids Cancer Predisposition Screening Program can coordinate care and perform screening tests that try to find cancer earlier. Depending on the type of hereditary cancer syndrome, the team may also discuss ways to reduce that risk, such as surgery or medication. In 2017, Dr. Walsh played a leading role in an international meeting of the American Association for Cancer Research, helping write screening recommendations for children who have a genetic predisposition to cancer.
Start the Conversation
If you would like to meet with one of our genetic counselors to learn about genetic testing and your family’s cancer risk, call us at 833-MSK-KIDS. We are waiting to take your call and can see you in a timely manner.
Genetic Testing at MSK Kids
The MSK Kids Clinical Genetics Service and Pediatric Cancer Predisposition Screening Program offers genetic testing for these and other rare genetic syndromes that raise the risk of cancer:
Multiple Cancer Predispositions
- Li-Fraumeni syndrome
- constitutional mismatch repair deficiency
Hematologic Malignancy (Blood Cancer) Predispositions
- PAX5
- RUNX1
- ETV6
- CEBPA
- IKZF1
- other predispositions to blood cancers
Bone Marrow Failure Syndromes
- Fanconi anemia
- dyskeratosis congenita
- Diamond-Blackfan anemia
- Shwachman-Diamond syndrome
- congenital neutropenia
Immunodeficiencies
- severe combined immunodeficiency
- hemophagocytic lymphohistiocytosis
Neuroectodermal Syndromes
- neurofibromatosis type 1
- NF2-related schwannomatosis
- schwannomatosis
- tuberous sclerosis
Solid Tumor Predispositions
- WT1-related disorders
- Beckwith-Wiedemann syndrome
- Simpson-Golabi-Behmel syndrome
- hereditary neuroblastoma
- hereditary retinoblastoma
- DICER1-related disorder
- nevoid basal cell carcinoma syndrome (Gorlin syndrome)
- PTEN hamartoma tumor syndrome
- rhabdoid tumor predisposition syndrome
- Von Hippel-Lindau syndrome
Polyposis Syndromes
- familial adenomatous polyposis
- juvenile polyposis syndrome
- Peutz-Jeghers syndrome
RASopathies
- Noonan syndrome
- Costello syndrome
Metabolic Cancer Predisposition Syndromes
- hereditary pheochromocytoma and paraganglioma
- hereditary leiomyomatosis and renal cell cancer
Endocrine Syndromes
- multiple endocrine neoplasia type 1
- multiple endocrine neoplasia type 2
To set up an appointment to discuss genetic testing, call 833-MSK-KIDS.
Frequently Asked Questions about Cancer Genetics
Genetics can be confusing. We’ve put together this list of frequently asked questions to help. Call us at anytime and we are happy to answer any other questions you have.
Can all cancer mutations be inherited?
No. Most genetic mutations in cancer are only in the cancer, not in the rest of the cells of the body. These are called somatic mutations. These mutations were not inherited from a person’s parents and cannot be passed down to their children. About one in ten children with cancer have a genetic change in all of the cells of their body that increases their risk for certain types of cancer. These are called germline mutations (because they come from the germ cells: the sperm or egg). Germline mutations in genes related to cancer usually cause a person to have a higher chance of developing certain types of cancer, which is called cancer predisposition. These types of changes usually can be inherited, although they won’t always be inherited. If a germline mutation is found in someone in your family, our team can help determine who else in your family may share this change and order genetic testing for those at risk.
How often do children inherit cancer from their parents?
About 10 percent of children with cancer have an inherited mutation that increases their risk of cancer. If an inherited mutation is related to your child’s cancer, we will let you know about the gene it affects, what type of mutation it is, and whether there is a chance that other family members may have it, too.
How is genetic testing done?
We typically start by testing the family member who already has cancer. We examine a sample of blood, saliva, or skin cells to see if there is a mutation. Since multiple cancer genes can cause the same type of cancer, we sometimes do what is called multigene panel testing to look at the DNA of several related cancer genes at the same time. This can be a quicker way to find the cause of cancer in a family. If we find a mutation, we can test other family members to see if they have it, too. A genetic counselor can explain the type of genetic test that would be best for you or your child.
Is there any harm to genetic testing? I’m nervous about learning my results.
There is no risk of physical harm other than the pinch of a blood draw. However, genetic testing can have emotional effects. It can be upsetting to learn that you or your family members have a mutation that raises your risk of getting cancer. There are other decisions you will weigh, such as whether your other children should be tested and whom to tell. Some of your relatives may not want to know the results. All of these concerns are valid. Your genetic counselor is ready to discuss them as well as any other questions or concerns you may have.
Can genetic test results be used against me?
Fear of discrimination is a common and understandable concern when thinking about having genetic testing. Genetic discrimination means that people are treated differently or unfairly because they have a genetic mutation that increases the risk of an inherited condition. A federal law called the Genetic Information Nondiscrimination Act (GINA) protects people from this kind of health insurance and employment discrimination. GINA does not protect against discrimination with other forms of insurance, such as life, disability, or long-term care insurance. We are happy to speak with you before testing to answer questions about this concern. For more information about GINA, read this fact sheet.
Are genetic test results private?
Absolutely. Genetic test results and medical records are kept completely private and confidential.
Can I just order a genetic test kit online? I’ve read about this on the Internet.
There are now ways for you to have your genetic information tested by buying a kit online or in a drugstore. This is called direct-to-consumer testing. While it may seem simple, understanding the results and what they mean for you and your family is not. Genetic testing can be complicated, and most direct-to-consumer tests are not regulated. This leaves room for error. Our specialists have the expertise to perform accurate genetic testing and the knowledge to carefully interpret and explain what your results mean so that you can make the most informed decisions about your healthcare.
What kinds of test results might there be? Will you explain them to me in a way I can understand?
Your genetic counselor will thoroughly explain your test results to you and what they mean. Genetic test results may be:
- Negative. This means we did not find a genetic mutation that increases cancer risk.
- Positive. This means there is a mutation present that affects cancer risk. We’ll explain the next steps to you, such as having increased screening, considering risk-reducing surgery, or talking to other family members about being tested.
- A variant of uncertain significance. This means we found a change in a gene but we don’t yet know what it means. Over time or through research, we may learn more about what the variant means. In the meantime, we’ll look at the rest of your medical and family history to make recommendations about cancer screening.
I’m worried I may conceive another child who develops cancer. How might my genetic test results affect how we plan our family?
This is a question that many parents ask us. The answer will depend on your child’s or your family’s genetic test results. When a mutation is known in a family, there are options that can help reduce the risk of cancer in future children. One option is testing embryos for a known mutation before they are implanted in a woman’s uterus during in vitro fertilization. This is called preimplantation genetic diagnosis. Our colleagues at Weill Cornell Medicine’s Center for Reproductive Medicine offer this service. Having children through adoption or with the assistance of donor eggs or donor sperm are other possible options for planning your family.
If you wish to explore any of these options, our genetic counselors can give you additional information or refer you to appropriate specialists in the New York City area or closer to your home. Whatever you choose to do, know that there is no right or wrong decision. Our goal is to give you the information to feel comfortable and confident with your choices.
I still have questions. Where can I learn more?
Just give us a call and we’ll arrange for you to speak with a genetic counselor from the MSK Kids Clinical Genetics Service. We are happy to help and can be reached at 833-MSK-KIDS.
MSK Kids Pediatric Cancer Genetics Publications
MSK Kids genetics experts have led or contributed to key initiatives that have defined the field of pediatric cancer genetics. Here are some publications our experts have taken part in:
A Cancer Legacy (2016)
Article in Science about the field of cancer predisposition that highlights MSK’s expertise in this area
Germline Mutations in Predisposition Genes in Pediatric Cancer (2015)
Defining the percentage of children with cancer predisposition
AACR Childhood Cancer Predisposition Workshop articles (2017)
Defining screening guidelines
Immune Checkpoint Inhibition for Hypermutant Glioblastoma Multiforme Resulting From Germline Biallelic Mismatch Repair Deficiency (2016)
A treatment advance for predisposed people
Integrating somatic variant data and biomarkers for germline variant classification in cancer predisposition genes (2018)
Classifying genetic variants and using tumor data to assess predisposed patients
Germline BRCA2 mutations detected in pediatric sequencing studies impact parents’ evaluation and care (2017)
The impact of an approach called cascade testing on family members
