Conditions + Treatments

Cancer Symptoms & Causes

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Contact Dana-Farber/ Boston Children's

We understand that you may have a lot of questions if your child has been diagnosed with pediatric cancer.

  • What type of cancer is it?
  • What are potential complications in my child’s case?
  • What are the treatments?
  • What are possible side effects from treatment?
  • How will it affect my child long term?

We’ve  provided some answers to those questions here, and when you meet with our experts, we can explain your child’s condition and treatment options fully.

What is cancer?

Cancer is an abnormal growth of cells. The cells are often shaped differently than healthy cells, don’t function properly and can spread to many areas of the body.Oncology is the study of cancer and tumors.

Tumors are clusters of cells that are capable of growing and dividing uncontrollably. They can be benign (non-cancerous) or malignant (cancerous):

  • Benign tumors tend to grow slowly and do not spread.
  • Malignant tumors grow rapidly, can invade and destroy nearby normal tissues and can spread throughout the body.

Generally, malignant cancers are more serious and are more likely to be life-threatening. However, sometimes a benign tumor can be difficult to treat because of its location, whereas certain kinds of malignant cancers respond very well to therapy. Your child’s physician can answer questions about the severity of your child’s specific type of cancer.

The term "cancer" is generally used when a tumor is malignant. There are two types of malignant tumors: "locally invasive" and "metastatic":

  • locally invasive - the tumor can invade the tissues surrounding it by sending out 'fingers' of cancerous cells into the normal tissue.
  • metastatic - the tumor can send cells in the blood stream and through lymph nodes into other tissues in the body, which may be far away from the original tumor.

"Staging" is the process of finding out whether cancer has spread and if so, how far. There is more than one system used for staging and your child’s physician can explain the stage of your child’s cancer.

It’s important to understand that cancer is not just one disease, but rather a group of diseases. All forms of cancer cause cells in the body to change and grow out of control.

How is pediatric cancer different from adult cancers?

There are big differences in the types of pediatric cancer and in survival rates. In general, childhood cancers are more successfully treated with a larger proportion of children cured compared with adult cancers. This difference is thought to be because childhood cancer is more responsive to therapy and a child can tolerate more intensive therapy when necessary.

What are the difference types of childhood cancer?

Childhood cancers vary widely in how they affect a child, so how doctors diagnose and treat your child will depend on your child’s unique circumstances. For more information about specific cancers, choose one below.

Hematologic malignancies

Solid tumors

Related diseases

Primary marrow dysfunction


Storage or metabolic diseases

  • Adrenal leukodystrophy (ALD)
  • Gaucher disease
  • Hurler syndrome
  • Mucopolysaccharidoses (MPS)


What causes cancer?

There is no one single cause of cancer. Scientists believe that it is the interaction of many factors that produces cancer. The factors involved may be genetic, environmental or behavioral. In almost all cases, the cause of childhood cancer is unknown.

It’s important to understand that there’s nothing you could have done or avoided doing that would have prevented your child’s cancer from developing.

What are the risk factors for cancer?

While the cause of cancer is generally unknown, some cancers, particularly in adults, have been associated with certain exposures or risk factors:

  • Lifestyle factors such as smoking, a high-fat diet and working with toxic chemicals may be risk factors for some adult cancers. Most children with cancer, however, are too young to have been exposed to these lifestyle factors for an extended time.

  • Family history, inheritance and genetics may play an important role in some childhood cancers.

  • Some genetic disorders (Wiskott-Aldrich and Beckwith-Wiedemann syndrome) are known to affect a child’s chance of developing cancer.

  • Exposures to certain viruses, such as the Epstein-Barr virus (EBV) and human immunodeficiency virus (HIV), have been linked to an increased risk of developing certain childhood cancers such as Hodgkin lymphoma  and non-Hodgkin lymphoma.  

  • Environmental exposures, such as pesticides, fertilizers and power lines have been researched for a direct link to childhood cancers, but there has been no conclusive evidence that any of those factors has causlymphomaed childhood cancer.

  • Some forms of high-dose chemotherapy and radiation have been linked to cancer. In some cases, children that have been exposed to these agents to treat cancer may develop a second cancer later in life.

How do genes affect cancer growth?

The discovery of certain types of genes that increase a person’s chances of developing cancer has been an extremely important development for cancer research. Genes make proteins. Altered genes (called mutations) cause altered proteins. Altered proteins cause tumors. Researchers have observed that more than 90 percent of cancers have some type of genetic alteration. Some of these alterations are inherited, while others occur by chance or as the result of environmental exposures.

Questions to ask your child’s doctor

After your child is diagnosed with cancer, you may feel overwhelmed with information. It can be easy to lose track of the questions that occur to you.

Lots of parents find it helpful to jot down questions as they arise – that way, when you talk to your child’s doctors, you can be sure that all of your concerns are addressed. If your child is old enough, you may want to suggest that he write down what he wants to ask his health care provider, too.

Some of the questions you may want to ask include:

  • What type of cancer does my child have?
  • Where is the cancer located and how might this affect my child’s treatment?
  • Has my child’s cancer spread?
  • What is the stage and sub-type of the cancer and what does that mean?
  • Can it be treated with surgery, chemotherapy and/or radiation?
  • Will my child need to be in the hospital?
  • What are the possible short and long-term complications of treatment? How will they be addressed?
  • What is the likelihood of cure?
  • What services are available to help my child and my family cope?


Q: Will my child be OK?
A: Today, about three-quarters of all children diagnosed with pediatric cancer will be cured. However, it’s important to understand that your child’s short-term health and long-term survival varies greatly depending on the specific type of cancer. Prompt medical attention and intensive therapy are very important, as is long-term follow-up care.

Q: How do you treat cancer?
A: There are many treatment options available for children and adolescents with cancer. Depending on the type of cancer, treatment may include: surgery, chemotherapy, radiation therapy and stem cell transplantation. There have been remarkable advances in cancer treatments, many of which use a less toxic approach to deliver good outcomes and fewer long-term side effects. The majority of children with cancer survive their disease and go on to lead full, productive lives. We take many factors into consideration, such as the type of cancer, its presence throughout the body, and your child's age and general health, when deciding what approach is best for your child.

Q: How do I know if the recommended treatment is the best one for my child?
A: The cancer experts at Dana-Farber Cancer Institute and Boston Children's Hospital are known around the world for the contributions their research and treatment efforts have played in improving the outcome for children diagnosed with cancer. If your child's cancer is rare or has unusual features, we will frequently contact our colleagues at other medical institutions to seek additional thoughts about the best treatment approach. We may recommend enrolling in a research study (clinical trial) if we think the trial offers the best possible approach.

Because our doctors participate in many national pediatric oncology groups focused on improving childhood cancer treatments, we offer access to many of these studies through Dana-Farber/Children's Hospital Cancer Center. However, if an appropriate treatment is unavailable through our program, we will work with our colleagues to arrange for you to receive the necessary treatment.

Q: Where will my child be treated?
A: Children treated through Dana-Farber/Boston Children’s Cancer and Blood Disorders Center receive outpatient care at the Jimmy Fund Clinic on the third floor of the Dana-Farber Cancer Institute. If your child needs to be admitted to the hospital, he will stay at Children’s Hospital Boston on the sixth or ninth floor of the Berthiaume Building. All diagnostic testing (X-rays etc.) is done at Children’s Hospital.

Q: What services are available to help my child and my family cope?
A: Above all, we are committed to designing a treatment plan that fits the individual needs and circumstances of your child, and to provide emotional and educational support for your entire family. We offer a variety of services to help you, your child and your family get through this difficult time.

Q: What is a clinical trial?
A: A clinical trial evaluates new, specific research approaches for a particular type of cancer, allowing new and better treatments to be determined.

Q: What kind of supportive or palliative care is available at Children’s?
A: When necessary, our Pediatric Advanced Care Team (PACT) is available to provide supportive treatments intended to optimize the quality of life and promote healing and comfort for children with life-threatening illness. In addition, PACT can provide psychosocial support and help arrange end-of-life care should that become necessary.

Clinical trials FAQ

Q: What is a clinical trial?
A: A clinical trial is a research study that uses volunteers to test new methods of screening, prevention, diagnosis or treatment of a disease. A cancer clinical trial is a research study that is designed to answer important questions about cancer diagnosis, treatment and prevention. If enrolling on a clinical trial is an option, your child's primary oncologist will explain what the treatment involves, its goals and objectives, and answer any questions you have about enrolling on the study.

Q: What is the purpose of a clinical trial?
A: Most clinical trials are designed to ask a question that hasn't been answered yet such as, "Does a certain medicine cure a disease, or make some of the symptoms go away?" The results help us learn which treatments are currently most effective for certain diseases.

For cancer in particular, medical research is very important. Clinical trials test the efficacy of new medications, evaluate new approaches designed to minimize long-term effects, and provide treatments to preserve quality of life during and after treatment.

Q: Why should my child enroll in a clinical trial?
A: Most pediatric cancers are treated at major medical institutions, which use state-of-the-art treatments. Many of these treatments are based on clinical trials. Clinical trials rely on scientific findings to investigate the newest medications and most advanced procedures to treat childhood cancer.

Doctors recommend what they believe will be the best treatment. In many cases, your child may receive the best care possible by following a plan outlined in a clinical trial.

Q: What if I want to remove my child from a clinical trial?
A: Participation in clinical trials is completely voluntary. Before we begin treating your child on the trial, we will fully explain all parts of the treatment plan and fill out formal consent forms. You may remove your child from the medical study at any time.

Q: Are there long-term benefits of clinical trials?
A: Clinical trials are important in the long-term treatment of childhood cancer, and discoveries made years ago through clinical trials are now the standard of care for many of the curable cancers. By participating in a trial, your child will help us develop improved treatments for future children with the same condition.

Q: How can I obtain additional information?
A: To help patients and families understand more about clinical trials, Dana-Farber Cancer Institute produced an informational video called "Entering a Clinical Trial: is it right for you?" The video explains how to evaluate, enroll and participate in a cancer clinical trial. If the video does not answer your question, our doctors and nurses are available to address your concerns.

Types of clinical trials

How are clinical trials categorized?

Clinical trials are categorized as Phase III, II or I. Classification depends on the purpose of the study and determines the total number of patients who may receive treatment on that clinical trial. Newly-diagnosed patients are often treated using a Phase III trial.

Phase III studies compare the new treatment to a standard (current, state-of-the-art) treatment. At the beginning of the study, doctors don't know if the new treatment is better than the standard treatment. Phase III trials typically enroll hundreds of patients, and are carried out in treatment centers nationwide. If a drug successfully completes the Phase III level of testing, the pharmaceutical company that makes it can apply for FDA approval for this use.

In cases when the standard of care or Phase III treatment is not effective, your child's healthcare team may recommend a Phase II trial.

Phase II studies investigate whether the new treatment works for a specific type of cancer. They also continue to evaluate the safety of the treatment. It is important to realize that it is not yet known whether a Phase II drug will be effective against your cancer. Phase II studies generally enroll no more than 100 people.

If the standard of care, or a Phase III or Phase II treatment does not deliver positive results, your child's primary oncologist may suggest enrolling your child on a Phase I study.
Phase I Studies primarily evaluate:

  • the safety of a new drug
  • how much and how often the drug needs to be given
  • what the side effects of the new drug are

This is the first level of testing for a new drug or a known drug given in a new way, but is generally based on laboratory testing or the safe dose of a similar drug given to other people. Very few patients are enrolled on Phase I trials and they are available only through select programs.

Two important aspects of Phase I trials are that:

  • Medications used in pediatric cancer clinical trials have usually been tested in adult trials before they are used in children. However, because you/your child might be one of the first pediatric patients in the world to receive the new drug, the side effects in children may not be known. 
  • Although this drug has shown promise in the laboratory or in adults, it is not known if it will work against your cancer.

If our physicians recommend enrolling your child on any clinical trial, they will explain its purpose, benefits, possible side effects and answer any questions you or your child have. You will also have to sign a consent form before any treatment begins.

We are grateful to have been ranked #1 on U.S. News & World Report's list of the best children's hospitals in the nation for the third year in a row, an honor we could not have achieved without the patients and families who inspire us to do our very best for them. Thanks to you, Boston Children's is a place where we can write the greatest children's stories ever told.”
- Sandra L. Fenwick, President and CEO

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