| Research Abstract |
Sixteen Japanese Ewing tumors were available for analysis of chromosomal aberrations by comparative genomic hybridization and 11 tumors for expression of chimeric EWS transcripts. These results in Japanese patients were compared with those of 62 ETs in European Caucasian patients registered in the European Intergroup Cooperative Ewing's Sarcoma Study. Ten of 11 Japanese ETs and 31 of 62 European Caucasian ETs had type I (EWS exon 7 to FLI1 exon 6) fusion transcripts. In Japanese ETs, the median numbers of chromosomal aberrations were 2.0 and 6.0 in 11 primary tumors and five relapsed tumors, respectively. In European Caucasian ETs, the median number of changes were 2.5 and 5.0 in 52 primary and 10 relapsed tumors, respectively. Frequent gains were 8q (38%), 8p (31%) and 12q (25%) in Japanese ETs and 8q (52%), 8p (48%) and 12q (19%) in European Caucasian ETs. Frequent losses were 19q (44%), 19p (38%) and 17p (25%) in Japanese ETs and 16q (21%), 19q (18%) and 17p (15%) in European Caucasian ETs. The incidence of losses of 19p (P=0.0215) and 19q (P=0.0277) were significantly higher in Japanese ETs than in European Caucasian ETs.
In 14 cases of synovial sarcoma, chromosomal aberrations were detected in 10 cases. Gain (4.4) was more frequent than loss (0.9). The frequent gain included in 12q15 (5 cases), 12q22 (5 cases), 12q24.3 (5 cases), the frequent losses existed in 3p14 (2 cases) and 6q (2 cases). High-level gain was observed in 12q15, 12q22, and 12q24.3. Gain of 12q15 (p=0.021) and 12q22 (p=0.021) were more frequent in monophasic type than in biphasic type. Gain of 3q32, 4q26-qter, 5p, 5q 14-q23, and 11p and loss of 1p33-pter, 3p21, 11q12, 16p, 17p, 22q were more frequently observed in European cases and gain of 12q 15 and 12q22 were frequent in Japanese cases.
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