Title:Genetics of Bladder Malignant Tumors in Childhood
Volume: 17
Issue: 1
Author(s): Andrea Zangari, Johan Zaini and Caterina Gulia
Affiliation:
Keywords:
RMS, Urothelial neoplasms, IMT, Pediatric age, Malignancy, Cancer genetics.
Abstract: Bladder masses are represented by either benign or malignant entities. Malignant bladder
tumors are frequent causes of disease and death in western countries. However, in children they are
less common. Additionally, different features are found in childhood, in which non epithelial tumors
are more common than epithelial ones. Rhabdomyosarcoma is the most common pediatric bladder tumor,
but many other types of lesions may be found, such as malignant rhabdoid tumor (MRT), inflammatory
myofibroblastic tumor and neuroblastoma. Other rarer tumors described in literature include
urothelial carcinoma and other epithelial neoplasms. Rhabdomyosarcoma is associated to a variety of genetic syndromes
and many genes are involved in tumor development. PAX3-FKHR and PAX7-FKHR (P-F) fusion state has important
implications in the pathogenesis and biology of RMS, and different genes alterations are involved in the pathogenesis
of P-F negative and embryonal RMS, which are the subsets of tumors most frequently affecting the bladder. These
genes include p53, MEF2, MYOG, Ptch1, Gli1, Gli3, Myf5, MyoD1, NF1, NRAS, KRAS, HRAS, FGFR4, PIK3CA,
CTNNB1, FBXW7, IGF1R, PDGFRA, ERBB2/4, MET, BCOR. Malignant rhabdoid tumor (MRT) usually shows
SMARCB1/INI1 alterations. Anaplastic lymphoma kinase (ALK) gene translocations are the most frequently associated
alterations in inflammatory myofibroblastic tumor (IMT). Few genes alterations in urothelial neoplasms have been reported
in the paediatric population, which are mainly related to deletion of p16/lnk4, overexpression of CK20 and overexpression
of p53. Here, we reviewed available literature to identify genes associated to bladder malignancies in children
and discussed their possible relationships with these tumors.
