Cancer in children
CANCER IN CHILDREN & YOUNG ADULTS
CANCER IN CHILDREN & YOUNG ADULTS DEFINITION
Although cancer in children is rare, it is the leading cause of death by disease past infancy among children in the United States. In 2014, it is estimated that 15,780 children and adolescents ages 0 to 19 years will be diagnosed with cancer and 1,960 will die of the disease in the United States.
The most common types of cancer diagnosed in children and adolescents are leukemia, brain and other central nervous system tumors, lymphoma, rhabdomyosarcoma, neuroblastoma, Wilms tumor, bone cancer, and gonadal (testicular and ovarian) germ cell tumors.
As of January 1, 2010, there were approximately 380,000 survivors of childhood and adolescent cancer (diagnosed at ages 0 to 19 years) alive in the United States. The number of survivors will continue to increase, given that the incidence of childhood cancer has been rising slightly in recent decades and that survival rates overall are improving.
CANCER IN CHILDREN & YOUNG ADULTS CAUSES
A risk factor is anything that affects the chance of getting a disease such as cancer. Different cancers have different risk factors.
Lifestyle-related risk factors play a major role in many types of cancer in adults. Examples include being overweight, eating an unhealthy diet, not getting enough exercise, and habits like smoking and drinking alcohol. But lifestyle factors usually take many years to influence cancer risk, and they are not thought to play much of a role in childhood cancers.
A few environmental factors, such as radiation exposure, have been linked with some types of childhood cancers. Some studies have also suggested that some parental exposures (such as smoking) might increase a child’s risk of certain cancers, but more studies are needed to explore these possible links. So far, most childhood cancers have not been shown to have outside causes.
In recent years, scientists have made great progress in understanding how certain changes in our DNA can cause cells to become cancerous. DNA is the chemical in each of our cells that makes up our genes – the instructions for nearly everything our cells do. We usually look like our parents because they are the source of our DNA. But DNA affects more than just how we look. It also influences our risks for developing certain diseases, including some kinds of cancer.
Some genes (parts of our DNA) control when our cells grow, divide into new cells, and die. Genes that help cells grow, divide, or stay alive are called oncogenes. Others that slow down cell division or cause cells to die at the right time are called tumor suppressor genes. Cancers can be caused by DNA changes that turn on oncogenes or turn off tumor suppressor genes.
Some children inherit DNA changes (mutations) from a parent that increase their risk of certain types of cancer. These changes are present in every cell of the child’s body, and can often be tested for in the DNA of blood cells or other body cells. Some of these DNA changes are linked only with an increased risk of cancer, while others can cause syndromes that also include other health or developmental problems.
But most childhood cancers are not caused by inherited DNA changes. They are the result of DNA changes that happen early in the child’s life, sometimes even before birth. Every time a cell prepares to divide into 2 new cells, it must copy its DNA. This process isn’t perfect, and errors sometimes occur, especially when the cells are growing quickly. This kind of gene mutation can happen at any time in life and is called an acquired mutation.
Acquired mutations start in one cell. That cell then passes the mutation on to all the cells that come from it. These acquired DNA changes are only in the person’s cancer cells and will not be passed on to his or her children.
Sometimes the causes of gene changes in certain adult cancers are known (such as cancer-causing chemicals in cigarette smoke), but the reasons for DNA changes that cause most childhood cancers are not known. Some may have outside causes like radiation exposure, and others may have causes that have not yet been found. But many are likely to be caused by random events that sometimes happen inside a cell, without having an outside cause.
CANCER IN CHILDREN & YOUNG ADULTS PATHOPHYSIOLOGY
Osteosarcoma is a bone tumor that can occur in any bone. It most commonly occurs in the long bones of the extremities near metaphyseal growth plates. The most common sites include the femur (42%), with 75% of tumors in the distal femur; tibia (19%), with 80% of tumors in the proximal tibia; and humerus (10%), with 90% of tumors in the proximal humerus. Other locations of note include the skull or jaw (8%) and pelvis (8%).
Any sarcoma that arises from bone is technically called an osteogenic sarcoma. Therefore, this term includes fibrosarcoma, chondrosarcoma, and osteosarcoma, all named for their morphologic characteristics. The focus of this article is osteosarcoma. Numerous variants of osteosarcoma are known and include conventional types (ie, osteoblastic, chondroblastic, fibroblastic types) and telangiectatic, multifocal, parosteal, and periosteal types.
CANCER IN CHILDREN & YOUNG ADULTS SYMPTOMS
Cancer can be hard to detect in children. Children with cancer may experience the following symptoms or signs. Sometimes, children with cancer do not show any of these symptoms. Or, these symptoms may be caused by a medical condition that is not cancer.
Many of the symptoms can be described using an acronym provided by The Pediatric Oncology Resource Center.
Continued, unexplained weight loss
Headaches, often with early morning vomiting
Increased swelling or persistent pain in the bones, joints, back, or legs
Lump or mass, especially in the abdomen, neck, chest, pelvis, or armpits
Development of excessive bruising, bleeding, or rash
Constant, frequent, or persistent infections
A whitish color behind the pupil
Nausea that persists or vomiting without nausea
Constant tiredness or noticeable paleness
Eye or vision changes that occur suddenly and persist
Recurring or persistent fevers of unknown origin
If you are concerned about one or more of the symptoms or signs on this list, please talk with your child’s doctor. Your doctor will ask how long and how often your child has been experiencing the symptom(s), in addition to other questions. This is to help find out the cause of the problem, called a diagnosis.
If cancer is diagnosed, relieving symptoms remains an important part of cancer care and treatment. This may also be called symptom management, palliative care, or supportive care. Be sure to talk with your child’s health care team about symptoms your child experiences, including any new symptoms or a change in symptoms.
CANCER IN CHILDREN & YOUNG ADULTS DIAGNOSIS
An estimated 69,212 adolescents and young adults (AYAs) ages 15–39 were diagnosed with cancer in 2011.This is about six times the number of cases diagnosed in children ages 0–14. The incidence of specific cancer types varies dramatically across the AYA age continuum. For example, leukemia, lymphoma, testicular cancer (germ cell tumors), and thyroid cancer are the most common cancer types in younger AYAs (15–24 years old). By ages 25–39, breast cancer and melanoma comprise a growing share of cancers among AYAs.
CANCER IN CHILDREN & YOUNG ADULTS TREATMENT
In general, cancer in children is uncommon, so it can be hard for doctors to determine the best treatment unless they know what has been most effective in other children. That’s why more than 60% of children younger than 15 years old with cancer are treated as part of a clinical trial. Clinical trials are research studies that compare standard treatments (the best proven treatments available) with newer approaches to treatments that may be more effective or test new treatments. Clinical trials may test such approaches as a new drug, a new combination of standard treatments, or new doses of current therapies. Studying new treatments involves careful monitoring using scientific methods, and all participants are followed closely to track their health and progress.
To take advantage of these newer treatments, all children with cancer should be treated at a specialized cancer center. Doctors at these centers have extensive experience in treating children with cancer and have access to the latest research. In many cases, a team of doctors works with a child and the family to provide care; this is called a multidisciplinary team.
Pediatric cancer centers often have extra support services for children and their families, such as child life specialists, nutritionists, physical and occupational therapists, social workers, counselors. Special activities and programs to help your child and family cope may also be available. As explained in the Overview, however, there are times when a teenager with cancer may need to be treated at an adult cancer center.
Descriptions of the most common treatment options for childhood cancer are listed below. The treatment of childhood cancer depends on several factors, including the type and stage of cancer, possible side effects, the family’s preferences, and the child’s overall health. Your child’s care plan may also include treatment for symptoms and side effects, an important part of cancer care. Take time to learn about all of your child’s treatment options and be sure to ask questions about things that are unclear. Also, talk about the goals of each treatment with your doctor and what to expect while receiving the treatment. The following are general descriptions of treatments that may be used as part of a child’s treatment plan. Learn more about treatments used for specific types of cancer and making treatment decisions.