Childhood Cancer Genomics (PDQ®) 6/8 —Health Professional Version - National Cancer Institute

Childhood Cancer Genomics (PDQ®)—Health Professional Version - National Cancer Institute

Sarcomas

In This Section

• Osteosarcoma
• Ewing Sarcoma
• Rhabdomyosarcoma

Osteosarcoma

The genomic landscape of osteosarcoma is distinctive from that of other childhood cancers. It is characterized by an exceptionally high number of structural variants with relatively small numbers of single nucleotide variants compared with many adult cancers.[1,2]

Key observations regarding the genomic landscape of osteosarcoma are summarized below:

• The number of structural variants observed for osteosarcoma is very high, at more than 200 structural variants per genome;[1,2] thus, osteosarcoma has the most chaotic genome among childhood cancers. The Circos plots shown in Figure 9 illustrate the exceptionally high numbers of intra- and inter-chromosomal translocations that typify osteosarcoma genomes.

  ENLARGE

  Figure 9. Circos plots of osteosarcoma cases from the National Cancer Institute's Therapeutically Applicable Research to Generate Effective Treatments (TARGET) project. The red lines in the interior circle connect chromosome regions involved in either intra- or inter-chromosomal translocations. Osteosarcoma is distinctive from other childhood cancers because it has a large number of intra- and inter-chromosomal translocations. Credit: National Cancer Institute.
• The number of mutations per osteosarcoma genome that affect protein sequence (approximately 25 per genome) is higher than that of some other childhood cancers (e.g., Ewing sarcoma and rhabdoid tumors) but is far below that for adult cancers such as melanoma and non-small cell lung cancer.[1,2]
• Genomic alterations in TP53 are present in most osteosarcoma cases, with a distinctive form of TP53 inactivation occurring by structural variations in the first intron of TP53that lead to disruption of the TP53 gene.[1] Other mechanisms of TP53 inactivation are also observed, including missense and nonsense mutations and deletions of the TP53gene.[1,2] The combination of these various mechanisms for loss of TP53 function leads to biallelic inactivation in most cases of osteosarcoma.
• MDM2 amplification is observed in a minority of osteosarcoma cases (approximately 5%) and provides another mechanism for loss of TP53 function.[1,2]
• RB1 is commonly inactivated in osteosarcoma, sometimes by mutation but more commonly by deletion.[1,2]
• Other genes with recurrent alterations in osteosarcoma include ATRX and DLG2.[1] Additionally, pathway analysis showed that the PI3K/mammalian target of rapamycin (mTOR) pathway was altered by mutation/loss/amplification in approximately one-fourth of patients, with PTEN mutation/loss being the most common alteration.[2]
• The range of mutations reported for osteosarcoma tumors at diagnosis do not provide obvious therapeutic targets, as they primarily reflect loss of tumor suppressor genes (e.g., TP53, RB1, PTEN) rather than activation of targetable oncogenes.

Several germline mutations are associated with susceptibility to osteosarcoma; Table 3 summarizes the syndromes and associated genes for these conditions.

Mutations in TP53 are the most common germline alterations associated with osteosarcoma. Mutations in this gene are found in approximately 70% of patients with Li-Fraumeni syndrome (LFS), which is associated with increased risk of osteosarcoma, breast cancer, various brain cancers, soft tissue sarcomas, and other cancers. While rhabdomyosarcoma is the most common sarcoma arising in patients aged 5 years and younger with TP53-associated LFS, osteosarcoma is the most common sarcoma in children and adolescents aged 6 to 19 years.[3] One study observed a high frequency of young osteosarcoma cases (age <30 years) carrying a known LFS-associated or likely LFS-associated TP53 mutation (3.8%) or rare exonic TP53 variant (5.7%), with an overall TP53mutation frequency of 9.5%.[4] Another study observed germline TP53 mutations in 7 of 59 osteosarcoma cases (12%) subjected to whole-exome sequencing.[2] Other groups have reported lower rates (3%–7%) of TP53 germline mutations in patients with osteosarcoma.[5,6]

Table 3. Genetic Diseases That Predispose to Osteosarcomaa

Syndrome	Description	Location	Gene	Function
AML = acute myeloid leukemia; IL-1 = interleukin-1; MDS = myelodysplastic syndrome; RANKL = receptor activator of nuclear factor kappa beta ligand; TNF = tumor necrosis factor.
aAdapted from Kansara et al.[7]
Bloom syndrome [8]	Rare inherited disorder characterized by short stature and sun-sensitive skin changes. Often presents with a long, narrow face, small lower jaw, large nose, and prominent ears.	15q26.1	BLM(RecQL3)	DNA helicase
Diamond-Blackfan anemia [9]	Inherited pure red cell aplasia. Patients at risk for MDS and AML. Associated with skeletal abnormalities such as abnormal facial features (flat nasal bridge, widely spaced eyes).		Ribosomal proteins	Ribosome production [9,10]
Li-Fraumeni syndrome [11]	Inherited mutation in TP53 gene. Affected family members at increased risk of bone tumors, breast cancer, leukemia, brain tumors, and sarcomas.	17p13.1	P53	DNA damage response
Paget disease [12]	Excessive breakdown of bone with abnormal bone formation and remodeling, resulting in pain from weak, malformed bone.	18q21-qa22	LOH18CR1	IL-1/TNF signaling; RANKL signaling pathway
		5q31
		5q35-qter
Retinoblastoma [13]	Malignant tumor of the retina. Approximately 66% of patients are diagnosed by age 2 years and 95% of patients by age 3 years. Patients with heritable germ cell mutations at greater risk of subsequent neoplasms.	13q14.2	RB1	Cell-cycle checkpoint
Rothmund-Thomson syndrome (also called poikiloderma congenitale) [14,15]	Autosomal recessive condition. Associated with skin findings (atrophy, telangiectasias, pigmentation), sparse hair, cataracts, small stature, and skeletal abnormalities. Increased incidence of osteosarcoma at a younger age.	8q24.3	RTS(RecQL4)	DNA helicase
Werner syndrome [16]	Patients often have short stature and in their early twenties, develop signs of aging, including graying of hair and hardening of skin. Other aging problems such as cataracts, skin ulcers, and atherosclerosis develop later.	8p12-p11.2	WRN(RecQL2)	DNA helicase; exonuclease activity

Refer to the following PDQ summaries for more information about these genetic syndromes:

• Genetics of Breast and Gynecologic Cancers (Li-Fraumeni syndrome).
• Genetics of Skin Cancer (Bloom syndrome, Rothmund-Thomson syndrome, and Werner syndrome).

(Refer to the PDQ summary on Osteosarcoma and Malignant Fibrous Histiocytoma Treatment for information about the treatment of osteosarcoma.)

Ewing Sarcoma

The detection of a translocation involving the EWSR1 gene on chromosome 22 band q12 and any one of a number of partner chromosomes is the key feature in the diagnosis of Ewing sarcoma (refer to Table 4).[17] The EWSR1 gene is a member of the TET family [TLS/EWS/TAF15] of RNA-binding proteins.[18] The FLI1 gene is a member of the ETS family of DNA-binding genes. Characteristically, the amino terminus of the EWSR1 gene is juxtaposed with the carboxy terminus of the STS family gene. In most cases (90%), the carboxy terminus is provided by FLI1, a member of the family of transcription factor genes located on chromosome 11 band q24. Other family members that may combine with the EWSR1 gene are ERG, ETV1, ETV4 (also termed E1AF), and FEV.[19] Rarely, TLS, another TET family member, can substitute for EWSR1.[20] Finally, there are a few rare cases in which EWSR1 has translocated with partners that are not members of the ETS family of oncogenes. The significance of these alternate partners is not known.

Besides these consistent aberrations involving the EWSR1 gene at 22q12, additional numerical and structural aberrations have been observed in Ewing sarcoma, including gains of chromosomes 2, 5, 8, 9, 12, and 15; the nonreciprocal translocation t(1;16)(q12;q11.2); and deletions on the short arm of chromosome 6. Trisomy 20 may be associated with a more aggressive subset of Ewing sarcoma.[21]

Three papers have described the genomic landscape of Ewing sarcoma and all show that these tumors have a relatively silent genome, with a paucity of mutations in pathways that might be amenable to treatment with novel targeted therapies.[22-24] These papers also identified mutations in STAG2, a member of the cohesin complex, in about 15% to 20% of the cases, and the presence of these mutations was associated with advanced-stage disease. CDKN2A deletions were noted in 12% to 22% of cases. Finally, TP53 mutations were identified in about 6% to 7% of cases and the coexistence of STAG2 and TP53 mutations is associated with a poor clinical outcome.[22-24]

Figure 10 below from a discovery cohort (n = 99) highlights the frequency of chromosome 8 gain, the co-occurrence of chromosome 1q gain and chromosome 16q loss, the mutual exclusivity of CDKN2A deletion and STAG2 mutation, and the relative paucity of recurrent single nucleotide variants for Ewing sarcoma.[22]

ENLARGE

Figure 10. A comprehensive profile of the genetic abnormalities in Ewing sarcoma and associated clinical information. Key clinical characteristics are indicated, including primary site, type of tissue, and metastatic status at diagnosis, follow-up, and last news. Below is the consistency of detection of gene fusions by RT-PCR and whole-genome sequencing (WGS). The numbers of structural variants (SV) and single-nucleotide variants (SNV) as well as indels are reported in grayscale. The presence of the main copy-number changes, chr 1q gain, chr 16 loss, chr 8 gain, chr 12 gain, and interstitial CDKN2A deletion is indicated. Listed last are the most significant mutations and their types. For gene mutations, “others” refers to: duplication of exon 22 leading to frameshift (STAG2), deletion of exon 2 to 11 (BCOR), and deletion of exons 1 to 6 (ZMYM3). Reprinted from Cancer Discovery, Copyright 2014, 4 (11), 1342–53, Tirode F, Surdez D, Ma X, et al., Genomic Landscape of Ewing Sarcoma Defines an Aggressive Subtype with Co-Association of STAG2 and TP53 mutations, with permission from AACR.

Ewing sarcoma translocations can all be found with standard cytogenetic analysis. A more rapid analysis looking for a break apart of the EWS gene is now frequently done to confirm the diagnosis of Ewing sarcoma molecularly.[25] This test result must be considered with caution, however. Ewing sarcomas that utilize the TLS translocations will have negative tests because the EWSR1 gene is not translocated in those cases. In addition, other small round tumors also contain translocations of different ETS family members with EWSR1, such as desmoplastic small round cell tumor, clear cell sarcoma, extraskeletal myxoid chondrosarcoma, and myxoid liposarcoma, all of which may be positive with a EWSfluorescence in situ hybridization (FISH) break-apart probe. A detailed analysis of 85 patients with small round blue cell tumors that were negative for EWSR1 rearrangement by FISH with an EWSR1 break-apart probe identified eight patients with FUS rearrangements.[26] Four patients who had EWSR1-ERG fusions were not detected by FISH with an EWSR1break-apart probe. The authors do not recommend relying solely on EWSR1 break-apart probes for analyzing small round blue cell tumors with strong immunohistochemical positivity for CD99.

Small round blue cell tumors of bone and soft tissue that are histologically similar to Ewing sarcoma but do not have rearrangements of the EWSR1 gene have been analyzed and translocations have been identified. These include BCOR-CCNB3, CIC-DUX4, and CIC-FOX4.[27-30] The molecular profile of these tumors is different from the profile of EWS-FLI1translocated Ewing sarcoma, and limited evidence suggests that they have a different clinical behavior. In almost all cases, the patients were treated with therapy designed for Ewing sarcoma on the basis of the histologic and immunohistologic similarity to Ewing sarcoma. There are too few cases associated with each translocation to determine whether the prognosis for these small round blue cell tumors is distinct from the prognosis of Ewing sarcoma of similar stage and site.[27-30]

Genome-wide association studies have identified susceptibility loci for Ewing sarcoma at 1p36.22, 10q21, and 15q15.[31-33] Deep sequencing through the 10q21.3 region identified a polymorphism in the EGR2 gene, which appears to cooperate with and magnify the enhanced activity of the gene product of the EWSR1-FLI1 fusion that is seen in most patients with Ewing sarcoma.[32] The polymorphism associated with the increased risk is found at a much higher frequency in whites than in blacks or Asians, possibly contributing to the epidemiology of the relative infrequency of Ewing sarcoma in the latter populations. Three new susceptibility loci have been identified at 6p25.1, 20p11.22, and 20p11.23.[33]

Table 4. EWS and TLS Fusions and Translocations in Ewing Sarcoma

TET Family Partner	Fusion With ETS-like Oncogene Partner	Translocation	Comment
aThese partners are not members of the ETS family of oncogenes.
EWS	EWSR1-FLI1	t(11;22)(q24;q12)	Most common; ~85% to 90% of cases
	EWSR1-ERG	t(21;22)(q22;q12)	Second most common; ~10% of cases
	EWSR1-ETV1	t(7;22)(p22;q12)	Rare
	EWSR1-ETV4	t(17;22)(q12;q12)	Rare
	EWSR1-FEV	t(2;22)(q35;q12)	Rare
	EWSR1-NFATc2a	t(20;22)(q13;q12)	Rare
	EWSR1-POU5F1a	t(6;22)(p21;q12)
	EWSR1-SMARCA5a	t(4;22)(q31;q12)	Rare
	EWSR1-ZSGa	t(6;22)(p21;q12)
	EWSR1-SP3a	t(2;22)(q31;q12)	Rare
TLS (also called FUS)	TLS-ERG	t(16;21)(p11;q22)	Rare
	TLS-FEV	t(2;16)(q35;p11)	Rare

(Refer to the PDQ summary on Ewing Sarcoma Treatment for information about the treatment of Ewing sarcoma.)

Rhabdomyosarcoma

The embryonal and alveolar histologies have distinctive molecular characteristics that have been used for diagnostic confirmation, and may be useful for assigning risk group, determining therapy, and monitoring residual disease during treatment.[34-38]

1. Embryonal histology: Embryonal tumors often show loss of heterozygosity at 11p15 and gains on chromosome 8.[39-41] Embryonal tumors have a higher background mutation rate and higher single-nucleotide variant rate than do alveolar tumors, and the number of somatic mutations increases with older age at diagnosis.[42,43] Genes with recurring mutations include those in the RAS pathway (e.g., NRAS, KRAS, HRAS, and NF1), which together are observed in approximately one-third of cases. Other genes with recurring mutations include FGFR4, PIK3CA, CTNNB1, FBXW7, and BCOR, all of which are present in fewer than 10% of cases.[42,43]
   Embryonal histology with anaplasia: Anaplasia has been reported in a minority of children with rhabdomyosarcoma, primarily arising in children with the embryonal subtype who are younger than 10 years.[44,45] Rhabdomyosarcoma with nonalveolar, anaplastic morphology may be a presenting feature for children with Li-Fraumeni syndrome and germline TP53 mutations.[46] Among eight consecutively presenting children with rhabdomyosarcoma and TP53 germline mutations, all showed anaplastic morphology. Among an additional seven children with anaplastic rhabdomyosarcoma and unknown TP53 germline mutation status, three of the seven children had functionally relevant TP53 germline mutations. The median age at diagnosis of the 11 children with TP53 germline mutation status was 40 months (range, 19–67 months).
2. Alveolar histology: About 70% to 80% of alveolar tumors are characterized by translocations between the FOXO1 gene on chromosome 13 and either the PAX3 gene on chromosome 2 (t(2;13)(q35;q14)) or the PAX7 gene on chromosome 1 (t(1;13)(p36;q14)).[34,39,47] Other rare fusions include PAX3-NCOA1 and PAX3-INO80D.[42] Translocations involving the PAX3 gene occur in approximately 59% of alveolar rhabdomyosarcoma cases, while the PAX7 gene appears to be involved in about 19% of cases.[34] Patients with solid-variant alveolar histology have a lower incidence of PAX-FOXO1 gene fusions than do patients showing classical alveolar histology.[48] For the diagnosis of alveolar rhabdomyosarcoma, FOXO1 gene rearrangement may be detected with good sensitivity and specificity using either fluorescence in situhybridization or reverse transcription–polymerase chain reaction.[49]
   The alveolar histology that is associated with the PAX7 gene in patients with or without metastatic disease appears to occur at a younger age and may be associated with longer event-free survival rates than those associated with PAX3 gene rearrangements.[50-55] Patients with alveolar histology and the PAX3 gene are older and have a higher incidence of invasive tumor (T2). Around 22% of cases showing alveolar histology have no detectable PAX gene translocation.[38,48] In addition to FOXO1 rearrangements, alveolar tumors are characterized by a lower mutational burden than are fusion-negative tumors, with fewer genes having recurring mutations.[42,43] BCOR and PIK3CA mutations and amplification of MYCN, MIR17HG, and CDK4 have also been described.
3. Spindle cell/sclerosing histology: Spindle cell/sclerosing rhabdomyosarcoma has been proposed as a separate entity in the World Health Organization Classification of Tumours of Soft Tissue and Bone.[56] For congenital/infantile spindle cell rhabdomyosarcoma, a study reported that 10 of 11 patients showed recurrent fusion genes. Most of these cases had truncal primary tumors, and no paratesticular tumors were found. Novel VGLL2 rearrangements were observed in seven patients (63%), including VGLL2-CITED2 fusion in four patients and VGLL2-NCOA2 in two patients.[57] Three patients (27%) harbored different NCOA2 gene fusions, including TEAD1-NCOA2in two patients and SRF-NCOA2 in one patient. All fusion-positive congenital/infantile spindle cell rhabdomyosarcoma patients with available long-term follow-up were alive and well, and no patients developed distant metastases.[57] Further study is needed to better define the prevalence and prognostic significance of these gene rearrangements in young children with spindle cell rhabdomyosarcoma.
   In older children and adults with spindle cell/sclerosing rhabdomyosarcoma, a specific MYOD1 mutation (p.L122R) has been observed in a large proportion of patients.[57-60] Activating PIK3CA mutations were common in MYOD1-mutated cases (4 of 10); when they were present, they were associated with sclerosing histology.[57] The presence of the MYOD1 mutation is associated with an increased risk of treatment failure.[57-59] In one study that included nine children aged 1 year or older with spindle cell/sclerosing histology and MYOD1 mutations, seven had a fatal outcome despite aggressive multimodality treatment.[57]

These findings highlight the important differences between embryonal and alveolar tumors. Data demonstrate that PAX-FOX01 fusion-positive alveolar tumors are biologically and clinically different from fusion-negative alveolar tumors and embryonal tumors.[38,61-64] In a study of Intergroup Rhabdomyosarcoma Study Group cases, which captured an entire cohort from a single prospective clinical trial, the outcome for patients with translocation-negative alveolar rhabdomyosarcoma was better than that observed for translocation-positive cases. The outcome was similar to that seen in patients with embryonal rhabdomyosarcoma and demonstrated that fusion status is a critical factor for risk stratification in pediatric rhabdomyosarcoma.

(Refer to the PDQ summary on Childhood Rhabdomyosarcoma Treatment for information about the treatment of childhood rhabdomyosarcoma.)

References

1. Chen X, Bahrami A, Pappo A, et al.: Recurrent somatic structural variations contribute to tumorigenesis in pediatric osteosarcoma. Cell Rep 7 (1): 104-12, 2014. [PUBMED Abstract]
2. Perry JA, Kiezun A, Tonzi P, et al.: Complementary genomic approaches highlight the PI3K/mTOR pathway as a common vulnerability in osteosarcoma. Proc Natl Acad Sci U S A 111 (51): E5564-73, 2014. [PUBMED Abstract]
3. Ognjanovic S, Olivier M, Bergemann TL, et al.: Sarcomas in TP53 germline mutation carriers: a review of the IARC TP53 database. Cancer 118 (5): 1387-96, 2012. [PUBMED Abstract]
4. Mirabello L, Yeager M, Mai PL, et al.: Germline TP53 variants and susceptibility to osteosarcoma. J Natl Cancer Inst 107 (7): , 2015. [PUBMED Abstract]
5. Toguchida J, Yamaguchi T, Dayton SH, et al.: Prevalence and spectrum of germline mutations of the p53 gene among patients with sarcoma. N Engl J Med 326 (20): 1301-8, 1992. [PUBMED Abstract]
6. McIntyre JF, Smith-Sorensen B, Friend SH, et al.: Germline mutations of the p53 tumor suppressor gene in children with osteosarcoma. J Clin Oncol 12 (5): 925-30, 1994. [PUBMED Abstract]
7. Kansara M, Thomas DM: Molecular pathogenesis of osteosarcoma. DNA Cell Biol 26 (1): 1-18, 2007. [PUBMED Abstract]
8. German J: Bloom's syndrome. XX. The first 100 cancers. Cancer Genet Cytogenet 93 (1): 100-6, 1997. [PUBMED Abstract]
9. Lipton JM, Federman N, Khabbaze Y, et al.: Osteogenic sarcoma associated with Diamond-Blackfan anemia: a report from the Diamond-Blackfan Anemia Registry. J Pediatr Hematol Oncol 23 (1): 39-44, 2001. [PUBMED Abstract]
10. Idol RA, Robledo S, Du HY, et al.: Cells depleted for RPS19, a protein associated with Diamond Blackfan Anemia, show defects in 18S ribosomal RNA synthesis and small ribosomal subunit production. Blood Cells Mol Dis 39 (1): 35-43, 2007 Jul-Aug. [PUBMED Abstract]
11. Li FP, Fraumeni JF Jr, Mulvihill JJ, et al.: A cancer family syndrome in twenty-four kindreds. Cancer Res 48 (18): 5358-62, 1988. [PUBMED Abstract]
12. Grimer RJ, Cannon SR, Taminiau AM, et al.: Osteosarcoma over the age of forty. Eur J Cancer 39 (2): 157-63, 2003. [PUBMED Abstract]
13. Wong FL, Boice JD Jr, Abramson DH, et al.: Cancer incidence after retinoblastoma. Radiation dose and sarcoma risk. JAMA 278 (15): 1262-7, 1997. [PUBMED Abstract]
14. Wang LL, Gannavarapu A, Kozinetz CA, et al.: Association between osteosarcoma and deleterious mutations in the RECQL4 gene in Rothmund-Thomson syndrome. J Natl Cancer Inst 95 (9): 669-74, 2003. [PUBMED Abstract]
15. Hicks MJ, Roth JR, Kozinetz CA, et al.: Clinicopathologic features of osteosarcoma in patients with Rothmund-Thomson syndrome. J Clin Oncol 25 (4): 370-5, 2007. [PUBMED Abstract]
16. Goto M, Miller RW, Ishikawa Y, et al.: Excess of rare cancers in Werner syndrome (adult progeria). Cancer Epidemiol Biomarkers Prev 5 (4): 239-46, 1996. [PUBMED Abstract]
17. 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]
18. Urano F, Umezawa A, Yabe H, et al.: Molecular analysis of Ewing's sarcoma: another fusion gene, EWS-E1AF, available for diagnosis. Jpn J Cancer Res 89 (7): 703-11, 1998. [PUBMED Abstract]
19. Hattinger CM, Rumpler S, Strehl S, et al.: Prognostic impact of deletions at 1p36 and numerical aberrations in Ewing tumors. Genes Chromosomes Cancer 24 (3): 243-54, 1999. [PUBMED Abstract]
20. Sankar S, Lessnick SL: Promiscuous partnerships in Ewing's sarcoma. Cancer Genet 204 (7): 351-65, 2011. [PUBMED Abstract]
21. 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]
22. Tirode F, Surdez D, Ma X, et al.: Genomic landscape of Ewing sarcoma defines an aggressive subtype with co-association of STAG2 and TP53 mutations. Cancer Discov 4 (11): 1342-53, 2014. [PUBMED Abstract]
23. Crompton BD, Stewart C, Taylor-Weiner A, et al.: The genomic landscape of pediatric Ewing sarcoma. Cancer Discov 4 (11): 1326-41, 2014. [PUBMED Abstract]
24. Brohl AS, Solomon DA, Chang W, et al.: The genomic landscape of the Ewing Sarcoma family of tumors reveals recurrent STAG2 mutation. PLoS Genet 10 (7): e1004475, 2014. [PUBMED Abstract]
25. Monforte-Muñoz H, Lopez-Terrada D, Affendie H, et al.: Documentation of EWS gene rearrangements by fluorescence in-situ hybridization (FISH) in frozen sections of Ewing's sarcoma-peripheral primitive neuroectodermal tumor. Am J Surg Pathol 23 (3): 309-15, 1999. [PUBMED Abstract]
26. Chen S, Deniz K, Sung YS, et al.: Ewing sarcoma with ERG gene rearrangements: A molecular study focusing on the prevalence of FUS-ERG and common pitfalls in detecting EWSR1-ERG fusions by FISH. Genes Chromosomes Cancer 55 (4): 340-9, 2016. [PUBMED Abstract]
27. Pierron G, Tirode F, Lucchesi C, et al.: A new subtype of bone sarcoma defined by BCOR-CCNB3 gene fusion. Nat Genet 44 (4): 461-6, 2012. [PUBMED Abstract]
28. Specht K, Sung YS, Zhang L, et al.: Distinct transcriptional signature and immunoprofile of CIC-DUX4 fusion-positive round cell tumors compared to EWSR1-rearranged Ewing sarcomas: further evidence toward distinct pathologic entities. Genes Chromosomes Cancer 53 (7): 622-33, 2014. [PUBMED Abstract]
29. Sugita S, Arai Y, Tonooka A, et al.: A novel CIC-FOXO4 gene fusion in undifferentiated small round cell sarcoma: a genetically distinct variant of Ewing-like sarcoma. Am J Surg Pathol 38 (11): 1571-6, 2014. [PUBMED Abstract]
30. Cohen-Gogo S, Cellier C, Coindre JM, et al.: Ewing-like sarcomas with BCOR-CCNB3 fusion transcript: a clinical, radiological and pathological retrospective study from the Société Française des Cancers de L'Enfant. Pediatr Blood Cancer 61 (12): 2191-8, 2014. [PUBMED Abstract]
31. Postel-Vinay S, Véron AS, Tirode F, et al.: Common variants near TARDBP and EGR2 are associated with susceptibility to Ewing sarcoma. Nat Genet 44 (3): 323-7, 2012. [PUBMED Abstract]
32. Grünewald TG, Bernard V, Gilardi-Hebenstreit P, et al.: Chimeric EWSR1-FLI1 regulates the Ewing sarcoma susceptibility gene EGR2 via a GGAA microsatellite. Nat Genet 47 (9): 1073-8, 2015. [PUBMED Abstract]
33. Machiela MJ, Grünewald TGP, Surdez D, et al.: Genome-wide association study identifies multiple new loci associated with Ewing sarcoma susceptibility. Nat Commun 9 (1): 3184, 2018. [PUBMED Abstract]
34. Barr FG, Smith LM, Lynch JC, et al.: Examination of gene fusion status in archival samples of alveolar rhabdomyosarcoma entered on the Intergroup Rhabdomyosarcoma Study-III trial: a report from the Children's Oncology Group. J Mol Diagn 8 (2): 202-8, 2006. [PUBMED Abstract]
35. Kelly KM, Womer RB, Barr FG: Minimal disease detection in patients with alveolar rhabdomyosarcoma using a reverse transcriptase-polymerase chain reaction method. Cancer 78 (6): 1320-7, 1996. [PUBMED Abstract]
36. Edwards RH, Chatten J, Xiong QB, et al.: Detection of gene fusions in rhabdomyosarcoma by reverse transcriptase-polymerase chain reaction assay of archival samples. Diagn Mol Pathol 6 (2): 91-7, 1997. [PUBMED Abstract]
37. Sartori F, Alaggio R, Zanazzo G, et al.: Results of a prospective minimal disseminated disease study in human rhabdomyosarcoma using three different molecular markers. Cancer 106 (8): 1766-75, 2006. [PUBMED Abstract]
38. Davicioni E, Anderson MJ, Finckenstein FG, et al.: Molecular classification of rhabdomyosarcoma--genotypic and phenotypic determinants of diagnosis: a report from the Children's Oncology Group. Am J Pathol 174 (2): 550-64, 2009. [PUBMED Abstract]
39. Merlino G, Helman LJ: Rhabdomyosarcoma--working out the pathways. Oncogene 18 (38): 5340-8, 1999. [PUBMED Abstract]
40. Koufos A, Hansen MF, Copeland NG, et al.: Loss of heterozygosity in three embryonal tumours suggests a common pathogenetic mechanism. Nature 316 (6026): 330-4, 1985 Jul 25-31. [PUBMED Abstract]
41. Scrable H, Witte D, Shimada H, et al.: Molecular differential pathology of rhabdomyosarcoma. Genes Chromosomes Cancer 1 (1): 23-35, 1989. [PUBMED Abstract]
42. Shern JF, Chen L, Chmielecki J, et al.: Comprehensive genomic analysis of rhabdomyosarcoma reveals a landscape of alterations affecting a common genetic axis in fusion-positive and fusion-negative tumors. Cancer Discov 4 (2): 216-31, 2014. [PUBMED Abstract]
43. Chen X, Stewart E, Shelat AA, et al.: Targeting oxidative stress in embryonal rhabdomyosarcoma. Cancer Cell 24 (6): 710-24, 2013. [PUBMED Abstract]
44. Kodet R, Newton WA Jr, Hamoudi AB, et al.: Childhood rhabdomyosarcoma with anaplastic (pleomorphic) features. A report of the Intergroup Rhabdomyosarcoma Study. Am J Surg Pathol 17 (5): 443-53, 1993. [PUBMED Abstract]
45. Qualman S, Lynch J, Bridge J, et al.: Prevalence and clinical impact of anaplasia in childhood rhabdomyosarcoma : a report from the Soft Tissue Sarcoma Committee of the Children's Oncology Group. Cancer 113 (11): 3242-7, 2008. [PUBMED Abstract]
46. Hettmer S, Archer NM, Somers GR, et al.: Anaplastic rhabdomyosarcoma in TP53 germline mutation carriers. Cancer 120 (7): 1068-75, 2014. [PUBMED Abstract]
47. Dumont SN, Lazar AJ, Bridge JA, et al.: PAX3/7-FOXO1 fusion status in older rhabdomyosarcoma patient population by fluorescent in situ hybridization. J Cancer Res Clin Oncol 138 (2): 213-20, 2012. [PUBMED Abstract]
48. Parham DM, Qualman SJ, Teot L, et al.: Correlation between histology and PAX/FKHR fusion status in alveolar rhabdomyosarcoma: a report from the Children's Oncology Group. Am J Surg Pathol 31 (6): 895-901, 2007. [PUBMED Abstract]
49. Thway K, Wang J, Wren D, et al.: The comparative utility of fluorescence in situ hybridization and reverse transcription-polymerase chain reaction in the diagnosis of alveolar rhabdomyosarcoma. Virchows Arch 467 (2): 217-24, 2015. [PUBMED Abstract]
50. Sorensen PH, Lynch JC, Qualman SJ, et al.: PAX3-FKHR and PAX7-FKHR gene fusions are prognostic indicators in alveolar rhabdomyosarcoma: a report from the children's oncology group. J Clin Oncol 20 (11): 2672-9, 2002. [PUBMED Abstract]
51. Krsková L, Mrhalová M, Sumerauer D, et al.: Rhabdomyosarcoma: molecular diagnostics of patients classified by morphology and immunohistochemistry with emphasis on bone marrow and purged peripheral blood progenitor cells involvement. Virchows Arch 448 (4): 449-58, 2006. [PUBMED Abstract]
52. Kelly KM, Womer RB, Sorensen PH, et al.: Common and variant gene fusions predict distinct clinical phenotypes in rhabdomyosarcoma. J Clin Oncol 15 (5): 1831-6, 1997. [PUBMED Abstract]
53. Barr FG, Qualman SJ, Macris MH, et al.: Genetic heterogeneity in the alveolar rhabdomyosarcoma subset without typical gene fusions. Cancer Res 62 (16): 4704-10, 2002. [PUBMED Abstract]
54. Missiaglia E, Williamson D, Chisholm J, et al.: PAX3/FOXO1 fusion gene status is the key prognostic molecular marker in rhabdomyosarcoma and significantly improves current risk stratification. J Clin Oncol 30 (14): 1670-7, 2012. [PUBMED Abstract]
55. Duan F, Smith LM, Gustafson DM, et al.: Genomic and clinical analysis of fusion gene amplification in rhabdomyosarcoma: a report from the Children's Oncology Group. Genes Chromosomes Cancer 51 (7): 662-74, 2012. [PUBMED Abstract]
56. Nascimento AF, Barr FG: Spindle cell/sclerosing rhabdomyosarcoma. In: Fletcher CDM, Bridge JA, Hogendoorn P, et al., eds.: WHO Classification of Tumours of Soft Tissue and Bone. 4th ed. Lyon, France: IARC Press, 2013, pp 134-5.
57. Alaggio R, Zhang L, Sung YS, et al.: A Molecular Study of Pediatric Spindle and Sclerosing Rhabdomyosarcoma: Identification of Novel and Recurrent VGLL2-related Fusions in Infantile Cases. Am J Surg Pathol 40 (2): 224-35, 2016. [PUBMED Abstract]
58. Kohsaka S, Shukla N, Ameur N, et al.: A recurrent neomorphic mutation in MYOD1 defines a clinically aggressive subset of embryonal rhabdomyosarcoma associated with PI3K-AKT pathway mutations. Nat Genet 46 (6): 595-600, 2014. [PUBMED Abstract]
59. Agaram NP, Chen CL, Zhang L, et al.: Recurrent MYOD1 mutations in pediatric and adult sclerosing and spindle cell rhabdomyosarcomas: evidence for a common pathogenesis. Genes Chromosomes Cancer 53 (9): 779-87, 2014. [PUBMED Abstract]
60. Szuhai K, de Jong D, Leung WY, et al.: Transactivating mutation of the MYOD1 gene is a frequent event in adult spindle cell rhabdomyosarcoma. J Pathol 232 (3): 300-7, 2014. [PUBMED Abstract]
61. Davicioni E, Anderson JR, Buckley JD, et al.: Gene expression profiling for survival prediction in pediatric rhabdomyosarcomas: a report from the children's oncology group. J Clin Oncol 28 (7): 1240-6, 2010. [PUBMED Abstract]
62. Williamson D, Missiaglia E, de Reyniès A, et al.: Fusion gene-negative alveolar rhabdomyosarcoma is clinically and molecularly indistinguishable from embryonal rhabdomyosarcoma. J Clin Oncol 28 (13): 2151-8, 2010. [PUBMED Abstract]
63. Davicioni E, Finckenstein FG, Shahbazian V, et al.: Identification of a PAX-FKHR gene expression signature that defines molecular classes and determines the prognosis of alveolar rhabdomyosarcomas. Cancer Res 66 (14): 6936-46, 2006. [PUBMED Abstract]
64. Skapek SX, Anderson J, Barr FG, et al.: PAX-FOXO1 fusion status drives unfavorable outcome for children with rhabdomyosarcoma: a children's oncology group report. Pediatr Blood Cancer 60 (9): 1411-7, 2013. [PUBMED Abstract]