A recent study shows that SYT-SSX2, the mutant gene in synovial sarcoma, activates the Wnt pathway which leads to disease progression:
http://www.ncbi.nlm.nih.gov/pubmed/23921231
In the study, they used a compound designed by Stemsynergy and managed to prevent tumor progression in mice:
http://www.fortmilltimes.com/2013/08/08/2877295/stemsynergy-announces-breakthrough.html
Human trials next?