Genetic analysis of childhood endodermal sinus tumors by comparative genomic hybridization

Childhood endodermal sinus tumors (CEST) are a distinct category of germ ce ll tumors that involve the testis and extragonadal sites of young children. Recurrent deletions of Ip and 6q have been reported by classic cytogenetic analysis of a small number of cases. Comparative genomic hybridization, a technique that screens the entire genome for genetic abnormalities, is appl ied to additionally define the genetic changes present in CESTs. Sixteen fr ozen CESTs (10 testicular, 6 extragonadal) obtained from Pediatric Oncology Group-affiliated institutions or from the Cooperative Human Tissue Network were analyzed. The most common changes were gain of 20q (10 tumors), 1q(6 tumors), 11q and 22 (4 tumors each), and loss of 6q (8 tumors with common d eleted region of 6q24-qter), 16q (4 tumors), and Ip (4 tumors). Localized r egions of gain were identified at 8q24 (2 tumors both showings c-myc amplif ication by fluorescence in situ hybridization). Gain of 12p, characteristic of adolescent germ cell tumor, was present in one testicular tumor. Compar ative genomic hybridization was useful in defining genetic differences betw een adult and childhood tumors, in determining the common regions deleted o n chromosome 6, and in identifying other involved loci to be correlated wit h clinical parameters in future studies.