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Unusual Cancers of Childhood Treatment (PDQ®): Treatment - Health Professional Information [NCI]

This information is produced and provided by the National Cancer Institute (NCI). The information in this topic may have changed since it was written. For the most current information, contact the National Cancer Institute via the Internet web site at http://cancer.gov or call 1-800-4-CANCER.

General Information About Unusual Cancers of Childhood

Introduction

Cancer in children and adolescents is rare, although the overall incidence of childhood cancer has been slowly increasing since 1975.[1] Referral to medical centers with multidisciplinary teams of cancer specialists experienced in treating cancers that occur in childhood and adolescence should be considered for children and adolescents with cancer. This multidisciplinary team approach incorporates the skills of the primary care physician, pediatric surgeons, radiation oncologists, pediatric medical oncologists/hematologists, rehabilitation specialists, pediatric nurse specialists, social workers, and others to ensure that children receive treatment, supportive care, and rehabilitation that will achieve optimal survival and quality of life. (Refer to the PDQ Supportive and Palliative Care summaries for specific information about supportive care for children and adolescents with cancer.)

Guidelines for pediatric cancer centers and their role in the treatment of pediatric patients with cancer have been outlined by the American Academy of Pediatrics.[2] At these pediatric cancer centers, clinical trials are available for most types of cancer that occur in children and adolescents, and the opportunity to participate in these trials is offered to most patients and their families. Clinical trials for children and adolescents diagnosed with cancer are generally designed to compare potentially better therapy with therapy that is currently accepted as standard. Most of the progress made in identifying curative therapy for childhood cancers has been achieved through clinical trials. Information about ongoing clinical trials is available from the NCI website.

Dramatic improvements in survival have been achieved for children and adolescents with cancer. Between 1975 and 2010, childhood cancer mortality decreased by more than 50%.[3] Childhood and adolescent cancer survivors require close monitoring because cancer therapy side effects may persist or develop months or years after treatment. (Refer to the PDQ summary on Late Effects of Treatment for Childhood Cancer for specific information about the incidence, type, and monitoring of late effects in childhood and adolescent cancer survivors.)

Childhood cancer is a rare disease, with about 15,000 cases diagnosed annually in the United States in individuals younger than 20 years.[4] The U.S. Rare Diseases Act of 2002 defines a rare disease as one that affects populations smaller than 200,000 persons. Therefore, all pediatric cancers are considered rare.

The designation of a rare tumor is not uniform among pediatric and adult groups. Adult rare cancers are defined as those with an annual incidence of fewer than six cases per 100,000 people, and are estimated to account for up to 24% of all cancers diagnosed in the European Union and about 20% of all cancers diagnosed in the United States.[5,6] Also, the designation of a pediatric rare tumor is not uniform among international groups, as follows:

  • The Italian cooperative project on rare pediatric tumors (Tumori Rari in Eta Pediatrica [TREP]) defines a pediatric rare tumor as one with an incidence of less than two cases per 1 million population per year and is not included in other clinical trials.[7]
  • The Children's Oncology Group (COG) has opted to define rare pediatric cancers as those listed in the International Classification of Childhood Cancer subgroup XI, which includes thyroid cancer, melanoma and nonmelanoma skin cancers, and multiple types of carcinomas (e.g., adrenocortical carcinoma, nasopharyngeal carcinoma, and most adult-type carcinomas such as breast cancer, colorectal cancer, etc.).[8] These diagnoses account for about 4% of cancers diagnosed in children aged 0 to 14 years, compared with about 20% of cancers diagnosed in adolescents aged 15 to 19 years (refer to Figures 1 and 2).[9]

    Most cancers within subgroup XI are either melanomas or thyroid cancer, with the remaining subgroup XI cancer types accounting for only 1.3% of cancers in children aged 0 to 14 years and 5.3% of cancers in adolescents aged 15 to 19 years.

These rare cancers are extremely challenging to study because of the low incidence of patients with any individual diagnosis, the predominance of rare cancers in the adolescent population, and the lack of clinical trials for adolescents with rare cancers such as melanoma.

Pie chart showing age-adjusted and age-specific cancer incidence rates for patients aged 0-14 years (SEER 2009-2012).
Figure 1. Age-adjusted and age-specific (0–14 years) Surveillance, Epidemiology, and End Results (SEER) cancer incidence rates from 2009 to 2012 by International Classification of Childhood Cancer group and subgroup and age at diagnosis, including myelodysplastic syndrome and group III benign brain/central nervous system tumors for all races, males, and females. Pie chart showing age-adjusted and age-specific cancer incidence rates for patients aged 15-19 years (SEER 2009-2012).
Figure 2. Age-adjusted and age-specific (15–19 years) Surveillance, Epidemiology, and End Results (SEER) cancer incidence rates from 2009 to 2012 by International Classification of Childhood Cancer group and subgroup and age at diagnosis, including myelodysplastic syndrome and group III benign brain/central nervous system tumors