Embryonal rhabdomyosarcoma (ERMS) is a rare histological form of cancer of connective tissue wherein the mesenchymally-derived malignant cells resemble the primitive developing skeletal muscle of the embryo. It is the most common soft tissue sarcoma occurring in children. ERMS is also known as Fusion-Negative rhabdomyosarcoma (FN-RMS), as tumors of this subtype are unified by their lack of a PAX3-FOXO1 fusion oncogene (or other PAX fusions seen in alveolar rhabdomyosarcoma).
ERMS (or FN-RMS) is the more common of two major sub-types of rhabdomyosarcoma, the other being alveolar rhabdomyosarcoma (ARMS) also known as Fusion Positive RMS (FP-RMS). Commonly, FN-RMS is driven by a mutation in the RAS family of proto-oncogenes, creating a powerful signal which is now known to promoter tumor growth by preventing muscle lineage progression by blocking expression of the transcription factor MYOG .Inhibition of this signaling pathway with trametinib has been recently shown to overcome this differentiation block and reduce tumor progression in animal models of FN-RMS.
FN-RMS has been informally classified as a "small round blue cell tumor" because of the characteristic microscopic appearance of its cells after histological staining with hematoxylin and eosin.
The prognosis for rhabdomyosarcoma has improved greatly in recent decades, with over 70% of patients surviving for five years after diagnosis. Nevertheless, some FN-RMS patients with a rare Leu122Arg mutation in MYOD1 gene have very poor outcome.
- Masola V, Maran C, Tassone E, Zin A, Rosolen A, Onisto M (2009). "Heparanase activity in alveolar and embryonal rhabdomyosarcoma: implications for tumor invasion". BMC Cancer. 9: 304. doi:10.1186/1471-2407-9-304. PMC 2743710. PMID 19715595.
- Shern, Jack F.; Chen, Li; Chmielecki, Juliann; Wei, Jun S.; Patidar, Rajesh; Rosenberg, Mara; Ambrogio, Lauren; Auclair, Daniel; Wang, Jianjun (Jan 2014). "Comprehensive genomic analysis of rhabdomyosarcoma reveals a landscape of alterations affecting a common genetic axis in fusion-positive and fusion-negative tumors". Cancer Discovery. 4 (2): 216–231. doi:10.1158/2159-8290.CD-13-0639. ISSN 2159-8290. PMC 4462130. PMID 24436047.
- Yohe, Marielle E.; Gryder, Berkley E.; Shern, Jack F.; Song, Young K.; Chou, Hsien-Chao; Sindiri, Sivasish; Mendoza, Arnulfo; Patidar, Rajesh; Zhang, Xiaohu (2018-07-04). "MEK inhibition induces MYOG and remodels super-enhancers in RAS-driven rhabdomyosarcoma". Science Translational Medicine. 10 (448): eaan4470. doi:10.1126/scitranslmed.aan4470. ISSN 1946-6234. PMID 29973406.
- Breitfeld PP, Meyer WH (August 2005). "Rhabdomyosarcoma: new windows of opportunity". Oncologist. 10 (7): 518–27. doi:10.1634/theoncologist.10-7-518. PMID 16079319.
- Kohsaka, Shinji; Shukla, Neerav; Ameur, Nabahet; Ito, Tatsuo; Ng, Charlotte K Y; Wang, Lu; Lim, Diana; Marchetti, Angela; Viale, Agnes (2014-05-04). "A recurrent neomorphic mutation in MYOD1 defines a clinically aggressive subset of embryonal rhabdomyosarcoma associated with PI3K-AKT pathway mutations". Nature Genetics. 46 (6): 595–600. doi:10.1038/ng.2969. ISSN 1061-4036. PMC 4231202. PMID 24793135.