Fortunately, cancer in children and adolescents is rare, although the overall incidence of childhood cancer has been slowly increasing since 1975. Children and adolescents with cancer should be referred to medical centers that have a multidisciplinary team of cancer specialists with experience treating the cancers that occur during childhood and adolescence. This multidisciplinary team approach incorporates the skills of the primary care physician, pediatric surgical subspecialists, radiation oncologists, pediatric 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. 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/families. Clinical trials for children and adolescents 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 therapies for childhood cancers has been achieved through clinical trials. Information about ongoing clinical trials is available from the NCI Web site.
Dramatic improvements in survival have been achieved for children and adolescents with cancer. Between 1975 and 2002, childhood cancer mortality has decreased by more than 50%. For Ewing sarcoma, the 5-year survival rate has increased over the same time from 59% to 76% for children younger than 15 years and from 20% to 49% for adolescents aged 15 to 19 years. Childhood and adolescent cancer survivors require close follow-up 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.Origin and Incidence of Ewing Sarcoma
Studies using immunohistochemical markers, cytogenetics,[4,5] molecular genetics, and tissue culture  indicate that Ewing sarcoma is derived from a primordial bone marrow–derived mesenchymal stem cell.[7,8] Older terms such as primitive neuroectodermal tumor, Askin tumor (Ewing sarcoma of chest wall), and extraosseous Ewing sarcoma (often combined in the term Ewing sarcoma family of tumors) refer to this same tumor.
The incidence of Ewing sarcoma is approximately three cases per 1 million per year and has remained unchanged for 30 years. Data from the Surveillance, Epidemiology, and End Results (SEER) registries report an overall incidence of Ewing sarcoma of one case per 1 million in the U.S. population. The incidence in patients aged 10 to 19 years is between nine and ten cases per 1 million. The same analysis suggests that the incidence of Ewing sarcoma in the United States is nine times greater in Caucasians than in African Americans.
The median age of patients with Ewing sarcoma is 15 years, and more than 50% of patients are adolescents. Well-characterized cases of Ewing sarcoma in neonates and infants have been described.[11,12] Based on data from 1,426 patients entered on European Intergroup Cooperative Ewing Sarcoma Studies (EI-CESS), 59% of patients are male and 41% are female. Primary sites of bone disease include the following:
- Lower extremity (41%).
- Pelvis (26%).
- Chest wall (16%).
- Upper extremity (9%).
- Spine (6%).
- Skull (2%).
For extraosseous primary tumors, the most common primary sites of disease include the following:
- Trunk (32%).
- Extremity (26%).
- Head and neck (18%).
- Retroperitoneum (16%).
- Other sites (9%).
Approximately 25% of patients will have metastatic disease at diagnosis.
The U.S. NCI SEER database was used to compare patients younger than 40 years with Ewing sarcoma who presented with skeletal and extraosseous primary sites. Patients with extraosseous Ewing sarcoma were more likely to be older, female, nonwhite, and have axial primary sites and were less likely to have pelvic primary sites when compared with patients with skeletal Ewing sarcoma.Table 1. Characteristics of Children With Extraosseous Ewing Sarcoma and Skeletal Ewing Sarcoma
|Characteristic||Extraosseous Ewing Sarcoma||Skeletal Ewing Sarcoma||P Value|
|Mean age (range), years||20 (0-39)||16 (0-39)||<.001|
|White (nonwhite race)||85% (15%)||93% (8%)||<.001|
|Axial primary sites (non-axial primary)||73% (27%)||54% (46%)||<.001|
|Pelvic primary sites (nonpelvic primary)||20% (80%)||27% (73%)||.001|
Prognostic Factors for Ewing Sarcoma
The two major types of prognostic factors for patients with Ewing sarcoma are as follows:Pretreatment factors
- Site of tumor: Patients with Ewing sarcoma in the distal extremities have the best prognosis. Patients with Ewing sarcoma in the proximal extremities have an intermediate prognosis, followed by patients with central or pelvic sites.[15-17] Patients with tumors of the sacrum have a very poor prognosis.
- Tumor size or volume: Tumor size or volume has been shown to be an important prognostic factor in most studies. Cutoffs of a volume of 100 mL or 200 mL and/or single dimension greater than 8 cm are used to define larger tumors. Larger tumors tend to occur in unfavorable sites.[17,19]
- Age: Infants and younger patients (aged <15 years) have a better prognosis than adolescents aged 15 years or older, young adults, or adults.[12,15-17] In North American studies, patients younger than 10 years have a better outcome than those aged 10 to 17 years at diagnosis (relative risk [RR], 1.4). Patients older than 18 years have an inferior outcome (RR, 2.5). A retrospective review of two consecutive German trials for Ewing sarcoma identified 47 patients older than 40 years. With adequate multimodal therapy, survival was comparable to the survival observed in adolescents treated on the same trials.
- Gender: Girls with Ewing sarcoma have a better prognosis than boys.[10,16]
- Serum lactate dehydrogenase (LDH): Increased serum LDH levels prior to treatment are associated with inferior prognosis. Increased LDH levels are also correlated with large primary tumors and metastatic disease.
- Metastases: Any metastatic disease defined by standard imaging techniques or bone marrow aspirate/biopsy by morphology is an adverse prognostic factor. The presence or absence of metastatic disease is the single most powerful predictor of outcome. Metastases at diagnosis are detected in about 25% of patients. Patients with metastatic disease confined to lung have a better prognosis than patients with extrapulmonary metastatic sites.[15,17,22] The number of pulmonary lesions does not seem to correlate with outcome, but patients with unilateral lung involvement do better than patients with bilateral lung involvement. Patients with metastasis to bone only seem to have a better outcome than patients with metastases to both bone and lung. Based on an analysis from the SEER database, regional lymph node involvement in patients is associated with an inferior overall outcome when compared with patients without regional lymph node involvement.
- Standard cytogenetics: Complex karyotype (defined as the presence of 5 or more independent chromosome abnormalities at diagnosis) and modal chromosome numbers lower than 50 appear to have adverse prognostic significance.
- Detectable fusion transcripts in morphologically normal marrow: Reverse transcriptase polymerase chain reaction can be used to detect fusion transcripts in bone marrow. In a single retrospective study utilizing patients with normal marrow morphology and no other metastatic site, fusion transcript detection in marrow was associated with an increased risk of relapse.
- Other biological factors: Overexpression of the p53 protein, Ki67 expression, and loss of 16q may be adverse prognostic factors.[28-30] High expression of microsomal glutathione S-transferase, an enzyme associated with resistance to doxorubicin, is associated with inferior outcome for Ewing sarcoma.
The following are not considered to be adverse prognostic factors for Ewing sarcoma:
- Pathologic fracture: Pathologic fractures do not appear to be a prognostic factor.
- Histopathology: The degree of neural differentiation is not a prognostic factor in Ewing sarcoma.[33,34]
- Molecular pathology: The EWS-FL1 translocation associated with Ewing sarcoma can occur at several potential breakpoints in each of the genes which join to form the novel segment of DNA. Once thought to be significant, two large series have shown the EWS-FL1 translocation breakpoint site is not an adverse prognostic factor.[36,37]
Multiple studies have shown that patients with minimal or no residual viable tumor after presurgical chemotherapy have a significantly better event-free survival compared with patients with larger amounts of viable tumor.[38-41] Female gender and younger age predict a good histologic response to preoperative therapy. For patients who receive preinduction and postinduction chemotherapy positron emission tomography (PET) scans, decreased PET uptake following chemotherapy correlated with good histologic response and better outcome.[43,44] Patients with poor response to presurgical chemotherapy have an increased risk for local recurrence.References
- Smith MA, Seibel NL, Altekruse SF, et al.: Outcomes for children and adolescents with cancer: challenges for the twenty-first century. J Clin Oncol 28 (15): 2625-34, 2010. [PUBMED Abstract]
- Guidelines for the pediatric cancer center and role of such centers in diagnosis and treatment. American Academy of Pediatrics Section Statement Section on Hematology/Oncology. Pediatrics 99 (1): 139-41, 1997. [PUBMED Abstract]
- Olsen SH, Thomas DG, Lucas DR: Cluster analysis of immunohistochemical profiles in synovial sarcoma, malignant peripheral nerve sheath tumor, and Ewing sarcoma. Mod Pathol 19 (5): 659-68, 2006. [PUBMED Abstract]
- Delattre O, Zucman J, Melot T, et al.: The Ewing family of tumors--a subgroup of small-round-cell tumors defined by specific chimeric transcripts. N Engl J Med 331 (5): 294-9, 1994. [PUBMED Abstract]
- Dagher R, Pham TA, Sorbara L, et al.: Molecular confirmation of Ewing sarcoma. J Pediatr Hematol Oncol 23 (4): 221-4, 2001. [PUBMED Abstract]
- Llombart-Bosch A, Carda C, Peydro-Olaya A, et al.: Soft tissue Ewing's sarcoma. Characterization in established cultures and xenografts with evidence of a neuroectodermic phenotype. Cancer 66 (12): 2589-601, 1990. [PUBMED Abstract]
- Suvà ML, Riggi N, Stehle JC, et al.: Identification of cancer stem cells in Ewing's sarcoma. Cancer Res 69 (5): 1776-81, 2009. [PUBMED Abstract]
- Tirode F, Laud-Duval K, Prieur A, et al.: Mesenchymal stem cell features of Ewing tumors. Cancer Cell 11 (5): 421-9, 2007. [PUBMED Abstract]
- Esiashvili N, Goodman M, Marcus RB Jr: Changes in incidence and survival of Ewing sarcoma patients over the past 3 decades: Surveillance Epidemiology and End Results data. J Pediatr Hematol Oncol 30 (6): 425-30, 2008. [PUBMED Abstract]
- Jawad MU, Cheung MC, Min ES, et al.: Ewing sarcoma demonstrates racial disparities in incidence-related and sex-related differences in outcome: an analysis of 1631 cases from the SEER database, 1973-2005. Cancer 115 (15): 3526-36, 2009. [PUBMED Abstract]
- Kim SY, Tsokos M, Helman LJ: Dilemmas associated with congenital ewing sarcoma family tumors. J Pediatr Hematol Oncol 30 (1): 4-7, 2008. [PUBMED Abstract]
- van den Berg H, Dirksen U, Ranft A, et al.: Ewing tumors in infants. Pediatr Blood Cancer 50 (4): 761-4, 2008. [PUBMED Abstract]
- Raney RB, Asmar L, Newton WA Jr, et al.: Ewing's sarcoma of soft tissues in childhood: a report from the Intergroup Rhabdomyosarcoma Study, 1972 to 1991. J Clin Oncol 15 (2): 574-82, 1997. [PUBMED Abstract]
- Applebaum MA, Worch J, Matthay KK, et al.: Clinical features and outcomes in patients with extraskeletal Ewing sarcoma. Cancer 117 (13): 3027-32, 2011. [PUBMED Abstract]
- Cotterill SJ, Ahrens S, Paulussen M, et al.: Prognostic factors in Ewing's tumor of bone: analysis of 975 patients from the European Intergroup Cooperative Ewing's Sarcoma Study Group. J Clin Oncol 18 (17): 3108-14, 2000. [PUBMED Abstract]
- Bacci G, Longhi A, Ferrari S, et al.: Prognostic factors in non-metastatic Ewing's sarcoma tumor of bone: an analysis of 579 patients treated at a single institution with adjuvant or neoadjuvant chemotherapy between 1972 and 1998. Acta Oncol 45 (4): 469-75, 2006. [PUBMED Abstract]
- Rodríguez-Galindo C, Liu T, Krasin MJ, et al.: Analysis of prognostic factors in ewing sarcoma family of tumors: review of St. Jude Children's Research Hospital studies. Cancer 110 (2): 375-84, 2007. [PUBMED Abstract]
- Bacci G, Boriani S, Balladelli A, et al.: Treatment of nonmetastatic Ewing's sarcoma family tumors of the spine and sacrum: the experience from a single institution. Eur Spine J 18 (8): 1091-5, 2009. [PUBMED Abstract]
- Ahrens S, Hoffmann C, Jabar S, et al.: Evaluation of prognostic factors in a tumor volume-adapted treatment strategy for localized Ewing sarcoma of bone: the CESS 86 experience. Cooperative Ewing Sarcoma Study. Med Pediatr Oncol 32 (3): 186-95, 1999. [PUBMED Abstract]
- Grier HE, Krailo MD, Tarbell NJ, et al.: Addition of ifosfamide and etoposide to standard chemotherapy for Ewing's sarcoma and primitive neuroectodermal tumor of bone. N Engl J Med 348 (8): 694-701, 2003. [PUBMED Abstract]
- Pieper S, Ranft A, Braun-Munzinger G, et al.: Ewing's tumors over the age of 40: a retrospective analysis of 47 patients treated according to the International Clinical Trials EICESS 92 and EURO-E.W.I.N.G. 99. Onkologie 31 (12): 657-63, 2008. [PUBMED Abstract]
- Miser JS, Krailo MD, Tarbell NJ, et al.: Treatment of metastatic Ewing's sarcoma or primitive neuroectodermal tumor of bone: evaluation of combination ifosfamide and etoposide--a Children's Cancer Group and Pediatric Oncology Group study. J Clin Oncol 22 (14): 2873-6, 2004. [PUBMED Abstract]
- Paulussen M, Ahrens S, Craft AW, et al.: Ewing's tumors with primary lung metastases: survival analysis of 114 (European Intergroup) Cooperative Ewing's Sarcoma Studies patients. J Clin Oncol 16 (9): 3044-52, 1998. [PUBMED Abstract]
- Paulussen M, Ahrens S, Burdach S, et al.: Primary metastatic (stage IV) Ewing tumor: survival analysis of 171 patients from the EICESS studies. European Intergroup Cooperative Ewing Sarcoma Studies. Ann Oncol 9 (3): 275-81, 1998. [PUBMED Abstract]
- Applebaum MA, Goldsby R, Neuhaus J, et al.: Clinical features and outcomes in patients with Ewing sarcoma and regional lymph node involvement. Pediatr Blood Cancer 59 (4): 617-20, 2012. [PUBMED Abstract]
- Roberts P, Burchill SA, Brownhill S, et al.: Ploidy and karyotype complexity are powerful prognostic indicators in the Ewing's sarcoma family of tumors: a study by the United Kingdom Cancer Cytogenetics and the Children's Cancer and Leukaemia Group. Genes Chromosomes Cancer 47 (3): 207-20, 2008. [PUBMED Abstract]
- Schleiermacher G, Peter M, Oberlin O, et al.: Increased risk of systemic relapses associated with bone marrow micrometastasis and circulating tumor cells in localized ewing tumor. J Clin Oncol 21 (1): 85-91, 2003. [PUBMED Abstract]
- Abudu A, Mangham DC, Reynolds GM, et al.: Overexpression of p53 protein in primary Ewing's sarcoma of bone: relationship to tumour stage, response and prognosis. Br J Cancer 79 (7-8): 1185-9, 1999. [PUBMED Abstract]
- López-Guerrero JA, Machado I, Scotlandi K, et al.: Clinicopathological significance of cell cycle regulation markers in a large series of genetically confirmed Ewing's sarcoma family of tumors. Int J Cancer 128 (5): 1139-50, 2011. [PUBMED Abstract]
- Ozaki T, Paulussen M, Poremba C, et al.: Genetic imbalances revealed by comparative genomic hybridization in Ewing tumors. Genes Chromosomes Cancer 32 (2): 164-71, 2001. [PUBMED Abstract]
- Scotlandi K, Remondini D, Castellani G, et al.: Overcoming resistance to conventional drugs in Ewing sarcoma and identification of molecular predictors of outcome. J Clin Oncol 27 (13): 2209-16, 2009. [PUBMED Abstract]
- Bramer JA, Abudu AA, Grimer RJ, et al.: Do pathological fractures influence survival and local recurrence rate in bony sarcomas? Eur J Cancer 43 (13): 1944-51, 2007. [PUBMED Abstract]
- Parham DM, Hijazi Y, Steinberg SM, et al.: Neuroectodermal differentiation in Ewing's sarcoma family of tumors does not predict tumor behavior. Hum Pathol 30 (8): 911-8, 1999. [PUBMED Abstract]
- Luksch R, Sampietro G, Collini P, et al.: Prognostic value of clinicopathologic characteristics including neuroectodermal differentiation in osseous Ewing's sarcoma family of tumors in children. Tumori 85 (2): 101-7, 1999 Mar-Apr. [PUBMED Abstract]
- de Alava E, Kawai A, Healey JH, et al.: EWS-FLI1 fusion transcript structure is an independent determinant of prognosis in Ewing's sarcoma. J Clin Oncol 16 (4): 1248-55, 1998. [PUBMED Abstract]
- van Doorninck JA, Ji L, Schaub B, et al.: Current treatment protocols have eliminated the prognostic advantage of type 1 fusions in Ewing sarcoma: a report from the Children's Oncology Group. J Clin Oncol 28 (12): 1989-94, 2010. [PUBMED Abstract]
- Le Deley MC, Delattre O, Schaefer KL, et al.: Impact of EWS-ETS fusion type on disease progression in Ewing's sarcoma/peripheral primitive neuroectodermal tumor: prospective results from the cooperative Euro-E.W.I.N.G. 99 trial. J Clin Oncol 28 (12): 1982-8, 2010. [PUBMED Abstract]
- Paulussen M, Ahrens S, Dunst J, et al.: Localized Ewing tumor of bone: final results of the cooperative Ewing's Sarcoma Study CESS 86. J Clin Oncol 19 (6): 1818-29, 2001. [PUBMED Abstract]
- Rosito P, Mancini AF, Rondelli R, et al.: Italian Cooperative Study for the treatment of children and young adults with localized Ewing sarcoma of bone: a preliminary report of 6 years of experience. Cancer 86 (3): 421-8, 1999. [PUBMED Abstract]
- Wunder JS, Paulian G, Huvos AG, et al.: The histological response to chemotherapy as a predictor of the oncological outcome of operative treatment of Ewing sarcoma. J Bone Joint Surg Am 80 (7): 1020-33, 1998. [PUBMED Abstract]
- Oberlin O, Deley MC, Bui BN, et al.: Prognostic factors in localized Ewing's tumours and peripheral neuroectodermal tumours: the third study of the French Society of Paediatric Oncology (EW88 study). Br J Cancer 85 (11): 1646-54, 2001. [PUBMED Abstract]
- Ferrari S, Bertoni F, Palmerini E, et al.: Predictive factors of histologic response to primary chemotherapy in patients with Ewing sarcoma. J Pediatr Hematol Oncol 29 (6): 364-8, 2007. [PUBMED Abstract]
- Hawkins DS, Schuetze SM, Butrynski JE, et al.: [18F]Fluorodeoxyglucose positron emission tomography predicts outcome for Ewing sarcoma family of tumors. J Clin Oncol 23 (34): 8828-34, 2005. [PUBMED Abstract]
- Denecke T, Hundsdörfer P, Misch D, et al.: Assessment of histological response of paediatric bone sarcomas using FDG PET in comparison to morphological volume measurement and standardized MRI parameters. Eur J Nucl Med Mol Imaging 37 (10): 1842-53, 2010. [PUBMED Abstract]
- Lin PP, Jaffe N, Herzog CE, et al.: Chemotherapy response is an important predictor of local recurrence in Ewing sarcoma. Cancer 109 (3): 603-11, 2007. [PUBMED Abstract]